Methods and devices for drug delivery to ocular tissue using microneedle.

(54) Title: METHODS AND DEVICES FOR THE ADMINISTRATION OF DRUGS TO THE EYE TISSUE USING A MICRO-NEEDLE.

(54) Title: METHODS AND DEVICES FOR DRUG DELIVERY TO OCULAR TISSUE USING MICRONEEDLE.

(57) Summary

Methods and devices are provided for targeted administration of a drug to a patient's eye. In one embodiment the method includes inserting a hollow microneedle into the sclera of the eye at an insertion site and infusing a fluid drug formulation through the inserted microneedle and into the suprachoroidal space of the eye, where the infused fluid drug formulation flows within the suprachoroidal space away from the insertion site during the infusion. The fluid drug formulation can flow circumferentially into the retinochoroidal tissue, macula, and optic nerve in the posterior segment of the eye.

(57) Abstract

Methods and devices are provided for targeted administration of a drug to a patient's eye. In one embodiment, the method ineludes inserting a hollow microneedle into the selera of the eye at an insertion site and infusing a fluid drug formulation through the inserted microneedle and into the suprachoroidai space of the eye, w herein the infused fluid drug formulation flow sw ithin the suprachoroidai space away from the insertion site during the infusion. The fluid drug formulation may How circumferentially tow ard the retinochoroidal tissue, macula, and optic nerve in the posterior segment of the eye.

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PATENT TITLE No. 360969

Headlines):

Home:

Denomination:

EMORY UNIVERSITY; GEORGIA TECH RESEARCH CORPORATION

1784 North Decatur Road, Suite 130, Atlanta, Georgia, 3022, USA.

METHODS AND DEVICES FOR THE ADMINISTRATION OF DRUGS TO THE EYE TISSUE USING A MICRO NEEDLE.

Classification: CIP

Inventor (s):

A61K9 / Q &amp; 5Al1FS / (»; f AplKD / IOs ,, A61M5 / 00; Α6 ^ ΐφΑΟΒ5Υ00ν ^ Ο7ΖΜ P27 / 06 CPC: ^ 61l £ W8 * A61F9 / 0017; A61K9 / 1 $ R $ IM6ft58; A61M31 / 00; A61M37 / 00 / 0015;

UM31R5? / O2; A61 P27 / fl »PASiMfl2 ^ / 002 &lt;A6ljl2037 / 0061: A61M2210 / 0612 MAF ^ X ^ PRAUSNITjZ *, hOW ^^ W &amp; HAUSEFrJsAWRKUMAR RAJNIKANT ΡΑφA61M5 / 31; A61M5 / 158;

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Number?

MX / a / 20 ^ / M, tZ

Industrial extendable, counted to ceilings.

the Industrial Property Law 999, 01/26/2004, 06/16/2005, the 1st, 3rd section V subsection a), 4 '___ signed on 07/01/2002, 07/15/2004, [ Organic tuto of the Mexican Institute of the 3rd and 5th Subsection a) of the Agreement that delegates regional offices, Divisional Deputy Directors, ístrial. (DOF 12/15/1999, amended on 02/04/2000,

Effective Date of V Exp Date

The reference patent in accordance with the ai from the date of presenti

Who subscribes to this title is (Official Gazette of the Federation '

01/25/2006, 05/06/2009, 01/06/2010, and 12th fractions I and III of Regulation 28/07/2004 and 09/07/2007); articles 1, 3,

Industrial Property (DOF 12/27/1999, refonmi faculties in the Deputy Directors General. Coi

Departmental Coordinators and other subordinates of 07/29/2004, 08/04/2004 and 09/13/2007).

This letter is signed with advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law, 3rd of its Regulations, and 1 section III, 2 section V, 26 BIS and 26 TER of the Agreement establishing the guidelines for the use of the Electronic Payment and Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.

THE DIVISIONAL DIRECTOR OF PATENTS

NAHANNY CANAL REYES

<img file="MX360969B_D0003.tif" />

Original string:

NAHANNY MARISOL CANAL REYES (00001000000403252793 | Tax Administration Service | 1695 || MX / 2019/516 | MX / a / 2012/012495 | Patent title PCT | 1027 | RGZ | Pág (s) | cX57ch3ywsuXgYzGWGimZILSOEE =

Digital stamp:

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5LmdWUJM60hl0yvY3KEfCAczlmQbiqS53SwscJfNwOOnqELZ1gz02nUt62X + y0VTJa3Ocffy7gzd11FITYgMe1iYwUXWXKXXKXXXKXXKXXKXXKXXHXWXKHXWXWXKWWHW

F92NJnrBh0YK / z2CIDOM8 / VPQg6z + DHZcjJfg22rq49EOT¡0uudsQdr41IYSwP7FZKfhcWw ==

Arenal No. 550, Floor 1, Pueblo Santa Mana Tepepan, Xochimilco, 16020, Mexico City.

(55) 53340700 wvvw gob.mx/impi

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METHODS AND DEVICES FOR THE ADMINISTRATION OF EYE TISSUE USING A MICROAGUJi

WFÍ

MEXICAN PROPERTY INSTITUTE

INDUSTRIAL

<img file="MX360969B_D0005.tif" />

STATEMENT IN RELATION TO RESEARCH OR DEVELOPMENT WITH FEDERAL FINANCING

The present invention was made with the support of the United States government pursuant to Contracts No. 8 RO1 EB00260-03 and No. R24EY017045-01, which were granted by the National Institute of Health. The United States government has certain rights regarding the invention.

BACKGROUND OF THE INVENTION

The present invention generally belongs to the field of ophthalmic therapies and more particularly to the use of a microneedle for injection of a fluid pharmacological formulation into eye tissues for targeted and localized administration of a drug.

Administration of a drug to the eye is extremely difficult, particularly administration of macromolecules and administration to the back of the eye. Many inflammatory and proliferative diseases of the posterior region of the eye require long-term pharmacological treatments. Examples of such diseases include macular degeneration, diabetic retinopathy, and uveitis. It is difficult to administer effective doses of the drug to the back of the eye using conventional administration methods such as topical application, which has very low efficacy, and systemic administration, which often causes significant side effects. (Geroski &amp; Edelhauser, Invest. Ophthalmol. Vis. Sci. 41: 961-64 (2000)). For example, while the drops are useful in treating diseases that affect the outer surface of the eye or the tissues in the front of the eye, the eye drops cannot penetrate significantly into the back of the eye, as might be the case. necessary for the treatment of various diseases of the retina.

IMPI

<img file="MX360969B_D0006.tif" />

Direct injection into the eye, using conventional needles and syringes Ό &amp; usually effective, but requires professional training and raises safety concerns (Maurice, J. Ocul. Pharmacol. Ther. 17: 393-401 (2001)). It would also be desirable to be able to minimize the number and / or frequency of eye injection treatments necessary to deliver therapeutically effective amounts of drug to the sites of eye tissue that need it.

The suprachoroidal space of the eye has been studied and its cannulation has been described as a possible route for drug administration. See for example, Olsen, et al., American J. Opthamology 142 (5): 777-87 (Nov. 2006); PCT Patent Application Publication No. WO 2007/100745 from Iscience Interventional Corporation.

Therefore, it would be desirable to provide better, safer, more effective techniques for the direct administration of therapeutic agents to the eye tissues. It would also be desirable to provide useful devices for such techniques that can be relatively inexpensive to produce and use. It would also be desirable to provide methods for the exact administration of the drug to the tissues of the sclera, choroid, uveal, macular, ciliary, vitreous, and retinal.

BRIEF DESCRIPTION OF THE INVENTION

Methods and devices are provided for the administration of a drug to the eye of a patient. The methods can be used, for example, in the treatment of uveitis, glaucoma, diabetic macular edema, age-related macular degeneration, or cytomegalovirus retinitis. In one aspect, the method includes inserting a hollow microneedle into the sclera of the eye at an insertion site, the needle having an opening at the tip; and injecting over a period of time a fluid pharmacological formulation, comprising a drug, through the inserted microneedle into the suprachoroidal space of the eye, where during the period the injected fluid pharmacological formulation flows into the suprachoroidal space and away from the insertion site during injection.

<img file="MX360969B_D0007.tif" />

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A, 1B, 1C and 1D are illustrations of cross sections of the tissue structures of a human eye. Entire eye (1A), corneal zoom (1B), and sclera and related tissues zoom in one eye without fluid in the suprachoroidal space (1C) or with fluid in the suprachoroidal space (ID) .

FIG. 2 is a cross sectional view of a microneedle device comprising a hollow microneedle arranged in an elongated body according to one embodiment.

FIG. 3 is a cross sectional view of the elongated body of the microneedle devices of FIG. 2.

FIG. 4 is an illustration of a microneedle device according to one embodiment.

FIG. 5 is an illustration of a microneedle device according to one embodiment.

FIGS. 6A and 6B illustrate one embodiment of a process for using a hollow microneedle to deliver drugs into the suprachoroidal space of the eye, where the process includes inserting the hollow microneedle into the sclera and injecting the fluid drug formulation into the suprachoroidal space.

FIG. 7A shows a comparison of a hollow microneedle according to an embodiment compared to a conventional 30 gauge hypodermic needle. FIG. 7B shows a schematic illustration of a custom acrylic mold to fit the entire eye.

FIGS. 8A and 8B are bright field microscope images of a sagittal cross section of a pig's eye before and after sulforadamine injection, respectively.

IMPI

<img file="MX360969B_D0008.tif" />

FIG. 9A, 9B, 9C and 9D are fluoroscopic images of a pig's eye cryosection without injection into the suprachoroidal space (9A), a cryosection of a rabbit's eye after injection of 500nm fluorescent particles in an axial plane and put as collage to form a panoramic view (9B), a cryosection of a pig's eye after injection of 500nm fluorescent particles in the sagittal direction and collage to show the anterior and posterior spaces for the microneedle insertion site (9C) and a cryosection of a human eye after injection of 500 nm fluorescent particles in the sagittal direction and collage to show the anterior and posterior spaces for the microneedle insertion site (9D). The boxes in FIG. 9B, 9C and 9D show enlarged views of the insert site of the microneedle.

FIGS. 10A and 10B are microcomputed tomography images showing the circumferential distribution of 1 pm contrast particles injected into the suprachoroidal space of a pig's eye in a cross-sectional image (10A) and the three-dimensional reconstruction of the cross-sectional images ( 10B).

FIGS. 11A, 11B, 11C and 11D are graphs showing the effect of injection pressure and microneedle length on the success rate of suprachoroidal administration of 20nm (11A) particles, of 100nm particles ( 11B), from 500nm particles (11C) and 1000nm particles (11D) in pig eyes.

FIGS. 12A and 12B are fluoroscopic images of a pig's eye cryosection after injection of 20nm (12A) particles and 1000nm (12B) particles in the sagittal direction and collage to show the anterior and posterior spaces for the microneedle insertion site. The boxes in FIG. 12A and 12B show enlarged views of the insert site of the microneedle.

FIGS. 13A and 13B are graphs showing the effect of infraocular pressure and microneedle length on the success rate of suprachoroidal delivery of 1000nm particles for simulated infraocular pressure of 18mmHg (13A) and 36mmHg (13B ).

IMPI

<img file="MX360969B_D0009.tif" />

FIG. 14 is a one-dimensional line of the visual scan of rabbit eyes after sodium fluorescein injection into the suprachoroidal space, where the "x" axis represents the position in the eye from the back (0) to the front (160 ) and the y-axis represents the fluorescent intensity at that position.

FIG. 15 is a graph showing the rate of sodium fluorescein clearance from the suprachoroidal space over time.

FIG. 16 is a graph showing the 20 nm particle clearance rate of the suprachoroidal space over time.

FIG. 17 is a graph showing the 500 nm particle clearance rate of the suprachoroidal space over time.

FIG. 18 is a block diagram of a method for administering a drug to the eye in accordance with one embodiment.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES

An effective drug delivery system for delivering a drug to the eye should optimally have four general characteristics: first, it should be minimally invasive and safe; second, the drug should be administered in such a way that it targets the desired tissues well and limits exposure to other regions of the eye; third, it should be able to control and sustain drug administration; and fourth, it should be as simple to use as possible. The modalities of the present disclosure address these needs by providing microneedle devices and methods to use them to improve the delivery of a drug to the eye.

In an advantageous and exemplary embodiment of the methods described herein, administration of a drug is accomplished by injecting (inserting) a microneedle into the sclera and injecting (infusing) a drug formulation through

<img file="MX360969B_D0010.tif" />

IMPI

MEXICAN INSTITUTE

OF THE INDUSTRIAL PROPERTY of the inserted microneedle to the suprachoroidal space of the eye. The microneedle is capable of precisely administering the drug into the suprachoroidal space for subsequent administration to nearby tissues that need treatment. The drug can be released into the eye tissues from the injected volume (or, for example, the microparticles in it) for an extended period, for example, several hours, or days, or weeks, or months, after the microneedle was inserted and withdrawal. This may beneficially provide increased bioavailability of the drug relative to, for example, administration, by topical application of the drug formulation to ocular tissue surfaces. With the present microneedle, the method advantageously includes precise control of the depth of insertion into the ocular tissue, so that the tip of the microneedle can be located in the suprachoroidal space or in the sclera but close enough to the suprachoroidal space for the injected drug formulation to flow into the suprachoroidal space. Advantageously, this can be accomplished without contacting the underlying tissues, such as the choroid and retina tissues.

The microneedles allow this administration to be performed in a minimally invasive manner superior to traditional needle approaches. For example, the microneedles herein can advantageously be inserted perpendicular to the sclera, reaching the suprachoroidal space at a short penetration distance. This is in contrast to the longer conventional needles or cannulas that must approach the suprachoroidal space at a steep angle, which involves a longer penetration passage through the sclera and other ocular tissues, increasing the size of the needle passage and consequently increasing the risk of infection and / or vascular rupture. With such long needles, the ability to precisely control insertion depth decreases relative to the microneedle approach described herein.

Advantageously, administration of the drug to the suprachoroidal space allows administration of the fluid drug formulation to a larger area of ​​tissue and to more difficult target tissues in single administration compared to previously known needle devices. Without sticking to any theory, it is believed that when the fluid drug formulation enters the suprachoroid space,

<img file="MX360969B_D0011.tif" />

ΙΜΡϊ

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY

<img file="MX360969B_D0012.tif" />

macula or optic nerve in the posterior segment of the eye, as well as anteriorly to the uvea and ciliary body. In addition, a portion of the injected fluid drug formulation may remain in the sclera near the microneedle insertion site, serving as a reservoir for the drug formulation that can subsequently diffuse into the suprachoroidal space and then into other adjacent tissues.

As used herein, the term suprachoroidal space, which is synonymous with suprachoroid or suprachoroid, describes a possible space in the region of the eye between the sclera and the choroid. This region is mainly composed of compactly grouped layers of long pigmented extensions derived from each of the two adjacent tissues; however, a space may develop in this region as a result of fluid or other material accumulation in the suprachoroidal space and adjacent tissues. Those skilled in the art will appreciate that the suprachoroid space frequently expands by fluid accumulation due to disease in the eye or as a result of trauma or surgical intervention. In the present disclosure, however, fluid accumulation is intentionally created by injecting a drug formulation into the suprachoroid to create a suprachoroid space (which is filled with the drug formulation). Without sticking to any theory, this region is believed to serve as a pathway for uveoscleral drainage (i.e., a natural process of fluid movement in the eye from one region to another) and becomes a real space in cases of choroidal detachment of the sclera.

Methods of using the microaauia

The microneedle devices described herein can be used to administer drug formulations to a patient's eye, particularly for the treatment, diagnosis, or prevention of eye disease. In a preferred embodiment, the patient is a human patient in need of treatment. The patient can be an adult or a child. In other embodiments, the patient may be a non-human mammal.

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IMPI

INSTITUTO MEXICAN, '· de: a moi; ε_Γαι-, ^ 'Dl'STRIAt

<img file="MX360969B_D0013.tif" />

A wide range of eye diseases and disorders can be treated by the methods and devices described herein. Non-limiting examples of eye diseases include uveitis, glaucoma, diabetic macular edema or retinopathy, macular degeneration, and genetic diseases. The methods described herein are particularly useful for the local administration of drugs that need to be administered to the posterior region of the eye, for example, the retinochoroidal tissue, macula, and optic nerve in the posterior segment of the eye. In one embodiment, the administration methods and devices described herein can be used in gene therapy applications. For example, the methods may deliver a fluid drug formulation into the suprachoroidal space to deliver selected DNA, RNA, or oligonucleotides to the target eye tissues.

The microneedles can be used for targeted administration to specific tissues or regions within the eye or in nearby tissue. In various modalities, the methods can be designed for drug delivery specifically to the sclera, Bruch's membrane, retinal pigment epithelium, subretinal space, retina, macula, optic disc, optic nerve, ciliary body, the trabecular meshwork, the aqueous humor, the vitreous humor and other ocular tissues or nearby tissues that need treatment.

As used herein, eye tissue and eye 10 include both the anterior segment 12 of the eye (i.e., the part of the eye in front of the lens and the posterior segment 14 of the eye (i.e., the part of the eye behind the lens). , as shown in FIG 1 A. The anterior segment 12 is joined by the cornea 16 and the lens 18, while the posterior segment 14 is joined by the sclera 20 and lens 18. Anterior segment 12 is further subdivided into anterior chamber 22, between iris 24 and cornea 18, and posterior chamber 26, between lens 18 and iris 24. The exposed part of sclera 20 in anterior segment 12 of The eye is protected by a transparent membrane referred to as the conjunctiva (not shown). Behind sclera 20 is choroid 28 and retina 27, collectively referred to as retinochoroidal tissue. The loose connective tissue, or potential space, between choroid 28 and sclera 20 is called the suprachoroidal space (not shown). FIG. 1B shows

IMPIOS

MEXICAN INSTITUTE ¿

OF IA PROPERTY

INDUSTRIAL ^^ ~ jarTg¡ and the cornea 16, which is composed of epithelium 30, Bowman's membrane 32. stroma 34, Descemet's membrane 36 and endothelium 38. FIG. 1C and FIG. 1D show the sclera 20 with the Tenon 40 capsule or conjunctiva around it 41, suprachoroidal space 42, choroid 28 and retina 27, with and without fluid in the suprachoroid space, respectively.

The method of administering a drug to the eye generally comprises the steps of inserting a hollow microneedle into the sclera and then injecting the fluid drug formulation through the hollow microneedle into the suprachoroidal space of the eye.

Insertion

In one embodiment, the insertion site is between the equator and the limbus of the eye. In another embodiment, the insertion site is between about 2mm and about 10mm behind the eye blade. In modalities, the microneedle insertion site is around the equator of the eye. In another embodiment, the insertion site is between the equator and the eye blade. In another embodiment, the insertion site is 2 to 10 mm behind the eye blade. In another embodiment, the drug formulation is introduced into the suprachoroidal space at the injection site (i.e., the tip of the microneedle) and then flows through the suprachoroidal space and away from the injection site while the injection is taking place . In another embodiment, the injection site (i.e., at the tip of the microneedle) is anterior to the equator of the eye and at least a portion of the drug formulation flows behind the equator of the eye during injection (i.e., while the drug formulation continues to flow from the microneedle). In another embodiment, the injection site (i.e., at the tip of the microneedle) is anterior to the equator of the eye, and at least part of the drug formulation flows close to the macula during injection (i.e., while the formulation pharmacology continues to flow from the microneedle).

It should be noted that the depth of insertion of the microneedle into the eye tissue is precisely controlled. Various methods can be employed to control the depth of insertion of the microneedles described herein. In a particular embodiment, the insert depth is limited by the selected length or the

<img file="MX360969B_D0014.tif" />

MEXICAN INSTITUTE OF LA FRO?; R.OAD

INDUSTRIAL

<img file="MX360969B_D0015.tif" />

effective length of the microneedle. The effective length is the part available for insertion into the tissue, that is, the length that extends from the base and would be inserted if there were no deformation in the tissue; it does not include any nearby parts of the microneedle that extend inward or through the base and therefore cannot be inserted into the tissue. That is, the microneedle can have a length approximately equal to the desired penetration depth. In one embodiment, the microneedle is short enough so that the tip of the microneedle can be inserted substantially at the base of the sclera (i.e., near the border of the sclera and choroid), without fully penetrating through the sclera. In another embodiment, the tip of the microneedle is inserted through the sclera into the suprachoroid space without penetrating through the choroid.

In another embodiment, the microneedles are designed to be longer than the desired depth of penetration, but the microneedles are inserted in a controlled manner only partially into the tissue. Partial insertion can be controlled by the mechanical properties of the tissue, which curves and hollows out during the micro-needle insertion process. In this way, as the microneedle is inserted into the tissue, its movement partially and elastically deforms the tissue and partially penetrates the tissue. By controlling the degree to which the tissue is deformed, the depth of insertion of the microneedle into the tissue can be controlled.

Additional insertion control features are described later in the Control Features for Direction of Microneedle Movement in Methods section below.

In another embodiment, a microneedle is inserted into the tissue using a rotary drill technique and / or a vibratory action. In this way, the microneedle can be inserted to a desired depth, for example, drilling with the microneedle a desired number of rotations, corresponding to a desired depth in the tissue. See, eg, US Patent Publication No. 20050137525 A1 to Wang et al., Which is incorporated herein in its entirety by this reference, for a disclosure of drill microneedles. The rotary drill technique and / or vibratory action can be applied during the insertion step, the retraction step, or both.

IMPI

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX360969B_D0016.tif" />

Invection

In a preferred embodiment, the fluid drug formulation is injected into the suprachoroidal space through a hollow microneedle by transferring the drug formulation from a source reservoir to the eye tissue using a pressure gradient (eg, pump, syringe). In other embodiments, the drug formulation can be transferred from a source reservoir to the eye tissue using an electric hood (eg, iontophoresis) or other externally applied energy (eg, ultrasound / acoustic energy).

In one embodiment, the amount of fluid drug formulation injected into the suprachoroidal space from the inserted microneedle is from 10 microliters to 200 microliters, for example from 50 to 150 pL. In another embodiment, from about 10 microliters to about 500 microliters, for example, from 50 to 250 pL, are injected through the microneedle into the suprachoroidal space.

In one embodiment, the transfer force or injection pressure of the fluid drug formulation through the microneedle causes the fluid drug formulation to flow into the suprachoroid space and reach the back of the eye during the administration process (i.e., during the injection). This can occur in less than one or two minutes, such as 1 second to 100 seconds, for example, 10 seconds to 30 seconds. In one aspect, the fluid drug formulation conveniently flows circumferentially within the suprachoroidal space during the injection process to a site that is at least 2.5 mm from the insertion site, to a site that is at least 5 mm from the site of insertion or to a site that is at least 10 mm from the insertion site. Conveniently, the fluid drug formulation flows circumferentially within the suprachoroidal space from the insertion site to the back of the eye (i.e., the retinochoroidal tissue, macula, and optic nerve in the posterior segment of the eye).

The amount of drug administered into the eye tissue can also be controlled, in part, by the type of microneedle used and the mode of use of

<img file="MX360969B_D0017.tif" />

this. In one exemplary embodiment, a hollow microneedle is inserted into the occuter tissue-and ----- is progressively retracted from the ocular tissue after insertion to deliver a fluid drug, where after achieving a certain dosage, administration may stop by deactivating the fluid transfer force, such as pressure (for example, from a mechanical device, such as a syringe) or an electric field, to avoid uncontrolled drug loss / administration. Conveniently, the amount of drug administered is controlled by transferring the fluid drug formulation to a suitable injection pressure. In certain embodiments, the injection pressure may be at least 150 kPa, at least 250 kPa, or at least 300 kPa. The appropriate injection pressure may vary with the particular patient or species.

Those skilled in the art will appreciate, however, that the desired injection pressure to administer an adequate amount of fluid drug formulation can be influenced by the insertion depth of the microneedle and the composition of the fluid drug formulation. For example, a higher injection pressure may be required in modalities where the fluid pharmacological formulation for administration to the eye is in the form of or includes nanoparticles or microparticles that encapsulate the active agent or microbubbles. Nanoparticle and microparticle encapsulation procedures are well known in the art.

Additional injection control characteristics are described later in the section Control of transport through the microneedle, later.

In one embodiment, the method of administering a drug to the eye may further include partial retraction of the hollow microneedle after the insertion step and before and / or during injection of the drug formulation. In a particular embodiment, the partial retraction of the microneedle occurs prior to the step of injecting the fluid drug formulation into the eye tissue. The insertion / retraction step can form a pocket and beneficially allow the fluid drug formulation to flow from the microneedle without being hampered or less hampered by eye tissue at the opening of the microneedle tip. This pocket can be filled with pharmacological formulation, but it also serves as a conduit through which the

<img file="MX360969B_D0018.tif" />

......."to"

IMPI

MEXICAN INSTITUTE ·.

INDUSTR INDUSTRIAL PROPERTY fluid drug formulation can flow from the microneedle, through the pocket into the suprachoroidal space. FIG. 6A shows a hollow microneedle 130 inserted into sclera 20, with pharmacological formulation 131 temporarily located in the cavity of the microneedle. (The communication between the fluid drug formulation and the reservoir is not shown.) FIG. 6B shows microneedle 130 after partial retraction and injection of fluid drug formulation 131 into the suprachoroidal space. The arrows show the circumferential fluid of the drug formulation through the suprachoroidal space.

In a particular embodiment, the microneedle injects a drug formulation through the sclera into the suprachoroidal space for a controlled (i.e., sustained, extended, or modulated over time) release of a drug to one or more nearby or ocular tissues. This sustained release or extended release or modulated release is generally more prolonged than that obtained by topical application of the drug formulation to the eye tissue. In a particular embodiment, there is an extended, sustained, or modulated release of the drug formulation after at least one needle is withdrawn from the eye tissue. This delivery method can be particularly advantageous with ocular tissues, where it is desirable that the insertion and removal process occur for as short a period of time as possible to minimize patient discomfort, compared to transdermal microneedle patch applications. , where the patches can usually be used (with inserted microneedles) for an extended period of time without patient discomfort.

Other steps, modalities and applications

In another aspect, the method of administering a drug to a patient's eye may include monitoring microneedle insertion and / or injection of the fluid drug formulation to ensure accurate release of the fluid drug formulation into the suprachoroidal space (FIG. 18). Such monitoring can be accomplished using image-assisted feedback methods during one or more of these steps, non-limiting examples include conventional microscopy, MRI, x-ray, confocal microscopy, optical coherence tomography (for example, CT scan).

IMPI

<img file="MX360969B_D0019.tif" />

anterior segment optical coherence, Heidelberg retinal tomography, spectral domain optical coherence tomography), fluorescein angiography, indocyanine green angiography, high-definition stereoscopic background photography, autofluorescence imaging, ultra-wide-field imaging, and various techniques ultrasound. Therefore, the method may further comprise determining whether an initial injection of the fluid drug formulation flowed into the suprachoroidal space of the eye and away from the insertion site. If an initial injection is determined to be successful, a desired volume of the fluid drug formulation can be injected, and the injection is interrupted by removing the fluid transfer force, such as pressure, and removing the microneedle from the eye. If, however, the initial injection of the fluid drug formulation is determined to be unsuccessful (i.e., substantially none of the drug formulation flowed into the suprachoroidal space of the eye and away from the insertion site), then the microneedle can be repositioned and the process can be repeated until successful administration is achieved.

The microneedle may optionally be part of a series of two or more needles such that the method additionally includes inserting at least a second microneedle into the sclera without penetrating through the sclera. In one embodiment, where a series of two or more microneedles are inserted into the eye tissue, the pharmaceutical formulations of each of the two or more microneedles may be identical or different from each other, in drugs, formulation, volume / quantity of pharmacological formulation, or a combination of these parameters. In one case, the different types of drug formulations can be injected using one or more microneedles. For example, inserting a second hollow microneedle comprising a second drug formulation into the eye tissue will result in the administration of a second drug formulation into the eye tissue.

The microneedle devices described herein can be adapted to remove substances, such as fluids, tissue, or samples of molecules from the eye.

Those of skill in the art will appreciate, however, that other types of microneedles (eg, solid microneedles) and other methods of administering the drug formulation into eye tissue may be used in place of or in conjunction with

IMPT

<img file="MX360969B_D0020.tif" />

with the injection methods described herein. River limiting examples - include dissolving, at least in part, a coating of a micro-needle drug formulation; peeling off, at least in part, a coating of a drug formulation (eg, as a substantially intact layer, or in fragments) from a microneedle; breaking or dissolving a microneedle from a base of which the microneedle forms an integral part of or is connected to it; or any combination of these.

The microneedle devices described herein can also be adapted for the use of one or more microneedles as a sensor to detect analytes, electrical activity, and optical or other signals. The sensor may include pressure, temperature, chemical, and / or electromagnetic field sensors (eg, light). Biosensors can be placed in or within the microneedle, or within the device in communication with body tissue through the microneedle. The microneedle biosensor can be any of four main transducer classes; potentiometric, amperometric, optical and physiochemical. In one embodiment, a hollow microneedle is filled with a substance, such as a gel, that has associated sensor functionality. In a detection application based on binding to a substrate or on an enzyme-mediated reaction, the substrate or enzyme can be immobilized inside the needle. In another embodiment, a waveguide may be incorporated into the microneedle device to direct light to a specific location, or for detection, for example, using means such as a pH dye for color evaluation. Similarly, heat, electricity, light, ultrasound, or other forms of energy can be accurately transmitted to directly stimulate, damage, or heal specific tissue or for diagnostic purposes.

The microneedle device

The microneedle device includes a hollow microneedle. The device may include an elongated cover to support the proximal end of the microneedle. The device further includes a means for driving a fluid drug formulation through the microneedle. For example, the medium may be a flexible or rigid conduit fluidly connected to the base or proximal end of the microneedle. The medium may also include a pump or other devices to create a gradient of

IMPI

<img file="MX360969B_D0021.tif" />

pressure to cause fluid to flow through the device. The conduit may have an operable connection to a source of the fluid drug formulation. The source can be any suitable container, in one embodiment, the source can be in the form of a conventional syringe. The source may be a desired unit dose container.

Microaauia

As used herein, the term "gap" includes a single, straight gap through the center of the microneedle, as well as multiple gaps that follow a complex passage through the microneedles, multiple entry and exit points from the or gaps and criss-cross or network gaps. That is, a hollow microneedle has a structure that includes one or more continuous passages from the base of the microneedle to an outlet point on the body part and / or the tip of the microneedle distal to the base.

As used herein, the term "microneedle" refers to a conduit body that has a base, a body, and a tip that is suitable for insertion into the sclera and other ocular tissues and that has dimensions suitable for insertion. minimally invasive and for injection of a fluid drug formulation, as described herein. That is, the microneedle has an effective length or length that does not exceed 2000 microns and a width (or diameter) that does not exceed 500 microns.

In various embodiments, the microneedle can be around 50 pm to 2000 pm in length. In another particular embodiment, the microneedle may have a length of from about 150 pm to about 1500 pm, from about 300 pm to about 1250 pm, from about 500 pm to about 1250 pm, from about 700 pm to around 1000 or around 800 to around 1000 pm. In a preferred embodiment, the length of the microneedle is around 1000 pm. In various modalities, the next part! of the microneedle has a maximum width or transverse dimension of about 50 pm to 500 pm, from about 50 pm to about 400 pm, from about 100 pm to about 400 pm, from about 200 pm to about

<img file="MX360969B_D0022.tif" />

E ¡? E la PRoriEr-Ai _s INDUSTRIAL **,

400 pm or from around 100 pm to around 250 pm, with an opening-from-around-the-clock fireplace from around 5 pm to around 400 pm. In a particular embodiment, the proximal portion of the microneedle has a maximum width or transverse dimension of about 400 µm.

Those skilled in the art will appreciate, however, that in embodiments where the tip of the microneedle is chamfered, the opening diameter may be greater than the outside diameter of the proximal portion of the microneedle. The microneedle may be manufactured to have an aspect ratio (anchovy) of from about 1: 1.5 to about 1:10. Other lengths, widths and aspect ratios are planned.

The microneedle can have a straight or tapered body. In one embodiment, the diameter of the microneedle is larger at the end of the microneedle base and is reduced to a point at the end distal to the base. The microneedle can also be manufactured to have a body that includes a straight (ie non-conical) part and a conical (eg, beveled) part. The microneedles can be formed by bodies that have a circular cross section in the perpendicular, or the cross section can be non-circular. The tip portion of the microneedles can have a variety of configurations. The tip of the microneedle can be symmetrical or asymmetric with respect to the longitudinal axis of the body. The tips can be chamfered, tapered, square or rounded. In particular embodiments, the microneedle may be designed such that the tip portion of the microneedle is basically the only portion of the microneedle that is inserted into the eye tissue (i.e., the tip portion is larger than 75 % of total microneedle length, greater than 85% of total microneedle length or greater than about 95% of total microneedle length). In other particular embodiments, the microneedle may be designed such that the tip portion of the microneedle is only a part of the microneedle that is inserted into the eye tissue and is generally less than about 75% of the total length of the the microneedle, less than about 50% of the total length of the microneedle or less than about 25% of the total length of the microneedle. For example, in one embodiment the microneedle has a total effective length of between 500 pm and 1000 pm, wherein the tip portion is less than about 400 pm in length, less than about 300 pm or less than about 200 p.m.

Base

<img file="MX360969B_D0023.tif" />

ΙΜ

The microneedle extends from a base. The base can be an integral part of or be separate from the microneedle. The base can be rigid or flexible. The base can be basically flat or it can be curved, for example, in the shape of the surface of the eye tissue at the injection site, or, for example, it can be curved contrary to the eye surface (for example, convex) in the form of minimize contact between the base and the eye tissue. Conveniently, the base is shaped to allow minimal contact with the surface of the eye at the point of insertion. For example, in one embodiment, the base extends only a minimum distance from the body of the microneedle, basically perpendicularly. In another embodiment, the base may be shaped so that it can lift the eye tissue toward the microneedle, to counteract the deviation of the eye tissue and facilitate insertion of the microneedle into the eye tissue (for example, the base can extend from the microneedle towards the tip part of the microneedle so as to pinch the eye tissue). Some of such embodiments may be based, at least in part, on the devices described in US Patent No. 6,743,211, the relevant disclosure of which is incorporated herein by this reference.

In a particular embodiment, the microneedle device has a single microneedle. In one embodiment, illustrated in FIG. 5, the microneedle device 130 is shown including a convex base 132 and a hollow microneedle 134 having a cavity 140, through which a fluid drug formulation (not shown) can be administered to the eye through the which biological fluid can be removed from the eye. Hollow microneedle 134 includes a proximal portion 136 and a tip 138.

The microneedle can extend from the base of the microneedle device at any angle suitable for insertion into the eye. In a particular embodiment, the microneedle extends from the base at an angle of about 90 degrees to provide approximately perpendicular insertion of the microneedles into the surface of the eye. In another particular embodiment, the microneedle extends from the base at an angle of about 60 to about 90 degrees.

Needle series

<img file="MX360969B_D0024.tif" />

In an alternative embodiment, the device includes a series of two or more microneedles. For example, the device may include a series of between 2 and 1000 microneedles (for example, between 2 and 100). In one embodiment, a device can include between 1 and 10 microneedles. A series of microneedles can include a mixture of different microneedles. For example, a series may include microneedles having different lengths, base part diameters, tip part shapes, spaces between microneedles, drug coatings, etc. In embodiments where the microneedle device comprises a series of two or more microneedles, the angle at which a single microneedle extends from the base may be independent of the angle at which another microneedle in the series extends from the base.

Device examples

FIGS. 2-5 show examples of modalities of microneedle devices. In one embodiment, FIG. 2-3, shows microneedle device 110 including a hollow microneedle 114 having a hollow cavity 140 through which a fluid pharmacological formulation (not shown) can be administered to the eye through which a biological fluid can be removed from the eye. The microneedle includes a proximal portion 116 and a tip 118. The microneedle 114 may extend from a base comprising, for example, an elongated body 112 having a distal end from which the proximal portion 116 and the tip 118 of the microneedle extend. The elongated body may further comprise a means for supporting 111 a portion of the base of the microneedle that extends beyond the distal end of base 112, such as a thread or a stem. An example of an embodiment of the elongated body 112 for holding the microneedle is shown in FIG. 3. and comprises a cover 113 and a base 115 having a recess 117 therein. Cap 113 and base 115 of elongated body 112 conveniently comprise a means for manually adjusting the length of the needle (i.e., the proximal end and tip of the microneedle extending from base 112) protruding from the elongated body cap. Said means may include, for example, threads 119 that allow it to screw and unscrew the cover 113 from the base part 115 of the elongated body. FIG. 4 shows an example of an embodiment where the base 115 of the elongated body can be operatively connected to an actuator 120 for the

<img file="MX360969B_D0025.tif" />

Controlada controlled injection of a fluid drug formulation through the microneedle into the suprachoroidal space.

The microneedle device may further comprise a reservoir for containing the fluid drug formulation, the fluid drug reservoir is operatively communicated with the hollow of the microneedle at a location distal to the tip end of the microneedle. The fluid reservoir may be an integral part of the microneedle, an integral part of the elongated body, or may be separate from the microneedle and the elongated body.

Manufacture of micro-guides

The microneedle can be formed by / being made from different biocompatible materials, including metals, glasses, semiconductor materials, ceramics or polymers. Examples of suitable metals include stainless steel, gold, titanium, nickel, iron, gold, tin, chromium, copper, and alloys of these suitable for pharmaceutical use. The polymer can be biodegradable or non-biodegradable. Examples of suitable biocompatible and biodegradable polymers include polylactides, polyglycolides, polylactide-co-glycolides (PLGA), polyanhydros, polyorthoesters, polyether esters, polycaprolactones, polyesteramides, (poly) butyric acid, (poly) valeric acid, polyurethanes, and copolymers. these. Representative non-biodegradable polymers include various thermoplastics and other known polymeric structural materials for the manufacture of medical devices. Examples include nylon, polyesters, polycarbonates, polyacrylates, polymers of ethylene-vinyl acetates and other acyl-substituted cellulose acetates, non-degradable polyurethanes, polystyrene, polyvinylchloride, polyvinyl fluoride, (poly) vinyl imidazole, chlorosulfonate polyolefins. , polyethylene oxide, mixtures and copolymers of these. Biodegradable microneedles can provide a higher level of safety when compared to non-biodegradable needles, so they are harmless even if they are inadvertently broken in eye tissue.

The microneedle can be manufactured by a variety of methods known in the art or as described in the Examples below. In one embodiment, the

<img file="MX360969B_D0026.tif" />

IMPI hollow microneedle is manufactured using a laser or a similar optical energy source. In one example, a microcannula can be cut using a laser to represent the desired microneedle length. The laser can also be used to shape one or multiple openings at the tip. One or multiple cuts can be made to a single microcannula to form the desired microneedle structure. In one example, the microcannula can be made of metal, such as stainless steel, and can be cut using a laser with a wavelength in the infrared region of the light spectrum (0.7 - 300 pm). Further refinement can be performed using metal electropolishing techniques known to those skilled in the art. In another embodiment, the microneedle length and optional beveling are formed from physical sharpening processes, which may include, for example, sharpening a metal cannula against a mobile abrasive surface. The manufacturing process may additionally include precision sharpening, microsphere jetting, and ultrasonic cleaning to achieve the precise desired shape of the microneedle tip.

Further details of possible manufacturing techniques are described, for example, in US Patent Application Publication No. 2006/0086689 A1 to Raju et al., US Patent Application Publication No. 2006/0084942 to Kim et al. , US Patent Application Publication No. 2005/0209565 to Yuzhakov et al., US Patent Application Publication No. 2002/0082543 A1 to Park et al., US Patent No. 6,334,856 to Alien et al., US Patent No. 6,611,707 to Prausnitz et al., US Patent No. 6,743,211 to Prausnitz et al., all of which are incorporated herein by this reference for their disclosure of microneedle manufacturing techniques.

Fluid drug formulation

The fluid drug formulation can be in the form of a liquid drug, a liquid solution that includes a drug in a suitable solvent, or a liquid suspension. The liquid suspension can include microparticles or nanoparticles dispersed in a liquid vehicle suitable for injections. In various embodiments, the drug can be included in the liquid vehicle, in the microparticles or nanoparticles, or in both. The fluid drug formulation is fluid enough to flow in and

<img file="MX360969B_D0027.tif" />

within the suprachoroidal space. In a preferk modality fluid drug formulation is around 1 cP at 37 ° C.

A wide variety of drugs for administration to ocular tissues can be formulated with the microneedle devices and methods herein. As used herein, the term "drug" refers to essentially any prophylactic, therapeutic, or diagnostic agent, i.e., a useful ingredient for medical, veterinary, or cosmetic applications. The drug can be selected from proteins, suitable peptides, and fragments thereof, which can be natural, synthesized, or recombinantly produced. The drug can be selected from suitable oligonucleotides (eg, antisense oligonucleotide agents), polynucleotides (eg, therapeutic DNA), ribozymes, dsRNA, siRNA, siRNA, gene therapy vectors, and / or vaccines for therapeutic use. The drug can be an aptamer (eg, an oligonucleotide or peptide molecule that binds to a specific target molecule).

Representative examples of the types of drug for administration to eye tissues include antibiotics, antiviral agents, analgesics, anesthetics, antihistamines, anti-inflammatory agents, and antineoplastic agents. Non-limiting examples of specific drugs and drug classes include β-adrenoceptor antagonists (eg, carteolol, cetamolol, betaxolol, levobunolol, metipranolol, timolol), miotics (eg, pilocarpine, carbachol, physostigmine), sympathomimetics (eg, adrenaline , dipivephrine), carbonic anhydrase inhibitors (for example acetazolamide, dorzolamide), prostaglandins, antimicrobial compounds, including antibacterial and antifungal (for example, chloramphenicol, chlortetracycline, ciprofloxacin, framycetin, fusidic acid, gentamicin, neomycin, norfloxacin, ofloxacin, polymyxin, propamidine, tetracycline, tobramycin, quinolines), antiviral compounds (eg acyclovir, cidofovir, idoxuridine) anti-inflammatory and / or antiallergic compounds (for example, steroidal compounds such as betamethasone, clobetasone, dexamethasone, fluorometolone, hydrocortisone, prednisolone and non-steroidal compounds such as antazoline, bromfenac, diclofenac, indomethacin, lodoxamide, saprofen, sodium cromoglycate), artificial / dry eye tear therapies, local anesthetics (eg ametocaine, lignocaine, oxbuprocaine,

<img file="MX360969B_D0028.tif" />

IMPI 'Ν ^ τιτυτο Mexican DF LA PROPIEDAD INDUSTRIAL proximelacaína), cyclosporine, diclofenac, urogastrone and growth factors, such as epidermal growth factor, mydriatics and cycloplegics, mitomycin C and collagenase inhibitors and treatments for macular degeneration related to age, such as sodium pegagtanib, ranibizumab, and bevacizumab.

In certain embodiments, the drug may be an integrin antagonist, a selectin agonist, an adhesion molecule antagonist (eg, Intercellular Adhesion Molecule (ICAM) -1, ICAM-2, ICAM-3, adhesion molecule platelet endothelial (PCAM), vascular cell adhesion molecule (VCAM)), or a cytokine that induces leukocyte adhesion or a growth factor antagonist (eg tumor necrosis factor-σ (TNF-σ), interleukin- 1 /? (IL-1 β), monocyte chemoattractant protein 1 (MCP-1) and an endothelial growth factor (VEGF)), as described in US Patent No. 6,524,581 to Adamis. In certain embodiments, the drug may be sub immunoglobulin antigen binding molecules, such as Fv immunoglobulin fragments, minibodies, and the like, as described in US Patent No. 6,773,916 to Thiel et al. In another embodiment, the drug can be a diagnostic agent, such as a contrast agent, known in the art.

The drug must commonly be formulated for storage and administration by the microneedle device described herein. The "pharmacological formulation" is a formulation of a drug, which commonly includes one or more pharmaceutically acceptable excipient materials known in the art. The term "excipient" refers to any non-active ingredient in the formulation that is intended to facilitate the handling, stability, dispersibility, humidification, release kinetics and / or injection of the drug. In one embodiment, the excipient may include or consist of water or saline.

In one embodiment, the fluid drug formulation includes microparticles or nanoparticles, each of which includes at least one drug. Desirably, the microparticles or nanoparticles provide controlled release of the drug into the eye tissue. As used herein, the term microparticle encompasses microspheres, microcapsules, microparticles, and beads, which have an average diameter number of 1 to 100 pm, more preferably 1 to 25 pm. The term

<img file="MX360969B_D0029.tif" />

IMPI nanoparticles are particles that have a diameter number of 10 to 1 ü Ί nm000 nm. The microparticles may or may not be spherical in shape. Microcapsules are defined as microparticles that have an outer shell that surrounds a core of other material. The core can be liquid, gel, solid, gas, or a combination of these. In one case, the microcapsule may be a microbubble with an outer shell surrounding a gas core, where the drug is disposed on the surface of the outer shell, in the outer shell itself, or in the core. (Microbubbles can respond to acoustic vibrations as known in the art for diagnosis, or explode the microbubble to release its charge at a selected site of ocular tissue.) The microspheres can be solid spheres, can be porous and include a sponge or honeycomb-like structure formed by pores or voids in a matrix or shell material, or they can include multiple separate voids in a matrix or shell material. The microparticles or nanoparticles can additionally include a matrix material. The shell or matrix material can be a polymer, amino acid, saccharide, or other material known in the microencapsulation art.

The drug-containing microparticles or nanoparticles can be suspended in an aqueous or non-aqueous liquid vehicle. The liquid vehicle can be a pharmaceutically acceptable aqueous solution and can optionally include a surfactant. The microparticles or nanoparticles or drugs themselves can include an excipient material, such as a polymer, a polysaccharide, a surfactant, etc., which are known in the art to control the kinetics of drug release from the particles.

In one embodiment, the fluid drug formulation further includes an agent effective in degrading collagen or GAG fibers in the sclera, which can improve drug penetration / release into eye tissue. This agent can be, for example, an enzyme, such as hyaluronldase, a collagenase, or a combination of these. In a variation of this method, the enzyme is administered into the eye tissue at a different step after, or before, the injection of the drug. The enzyme or drug is administered at the same site.

<img file="MX360969B_D0030.tif" />

IMPI

In another embodiment, the drug formulation passes through the phase of administration. For example, a liquid drug formulation can be injected through hollow microneedles into the suprachoroidal space, where it becomes thick and the drug spreads out of the gel for controlled release.

Control features to direct the movement of the microneedle in the methods of use

The microneedle device may comprise a means for controllably inserting, and optionally retracting, the microneedle into the eye tissue. Furthermore, the microneedle device may include a way to control the angle at which at least one microneedle is inserted into the eye tissue (for example, inserting the at least one microneedle into the surface of the eye tissue at an angle of about 90 degrees).

The depth of insertion of the microneedle into the eye tissue can be controlled by the length of the microneedle, as well as other geometric characteristics of the microneedle. For example, a bead or other sudden change in the width of the microneedle can be used to limit the depth of insertion of the microneedle. Insertion of the microneedle can also be controlled by using a mechanical micropositioning system involving gears or other mechanical components to move the microneedle into the eye tissue a controlled distance and, similarly, it can be operated, for example, on reverse, to retract the needle a controlled distance. The depth of insertion can also be controlled by the speed at which the microneedle is inserted into the eye tissue. The retraction distance can be controlled by elastic recoil of the eye tissue into which the microneedle is inserted or by including an elastic element within the microneedle device that pulls the microneedle a specified distance after the force is released. insertion.

The insertion angle can be directed by positioning the microneedle at a first angle relative to the base of the microneedle and positioning the base at a second angle relative to the ocular surface. In one embodiment, the first angle can be around 90 ° and the second angle

<img file="MX360969B_D0031.tif" />

<img file="MX360969B_D0032.tif" />

ΙΜΡΐ can be around 0 °. The insertion angle can also be directed by causing the needle to protrude from a cover of a device through a channel in that cover that is oriented at a specific angle.

One skilled in the art may adapt mechanical systems known in the art in combination with the disclosure set forth herein and in the Examples below to design suitable structures for controlled insertion of the microneedle, the structures of which can be manually operated, from electromechanical or a combination of these.

Transport control through the microneedle

Transport of the drug formulation or biological fluid through a hollow microneedle can be controlled or monitored through the use of, for example, one or more valves, pumps, sensors, thrusters, and microprocessors. For example, in one embodiment, the microneedle device may include a micropump, microvalve, and positioner with a microprocessor programmed to control a pump or valve to control the rate of delivery of a drug formulation through the microneedle into eye tissue. Flow through a microneedle can be delivered by scattering, capillary action, a mechanical pump, electroosmosis, electrophoresis, convection, or other conductive forces. Device and microneedle designs can be made by using known pumps and other devices to utilize these conductors. In one embodiment, the microneedle device may additionally include an iontophoretic apparatus, similar to those described in US Patent 6,319,240 to Beck, to improve delivery of the drug formulation to eye tissue. In another embodiment, the microneedle devices may additionally include a flow meter or other means to monitor flow through the microneedles and to coordinate the use of the pumps and valves.

The flow of the pharmacological formulation or biological fluid can be regulated using various valves or gates known in the art. The valve may be one that selectively and repeatedly opens and closes, or it may be a disposable one, such as a fracturable barrier. Other valves or doors used in the devices of

<img file="MX360969B_D0033.tif" />

<img file="MX360969B_D0034.tif" />

IM F!

microneedle can be activated thermally, electrochemically, mechanically ο_;<img file="MX360969B_D0035.tif" /> Magnetically to selectively start, modulate, or stop the flow of material through the microneedles. In one embodiment, flow is controlled with a membrane that limits speed by acting as a valve.

The present invention may be better understood by referring to the following non-exhaustive examples.

EXAMPLES

Experiments were carried out to assess whether the microneedles could be used to pierce to the base of the sclera and target the suprachoroidal space. More specifically, experiments were carried out to assess whether hollow microneedles could deliver small molecules and particles into the suprachoroidal space of eyes of human, rabbit, and pig carcasses. Additional experiments were carried out to measure the effect of microneedle length, injection pressure, and infraocular pressure on the delivery of particles that are 20 to 1000 nm in diameter in pig eyes. Finally, experiments were carried out to examine the role of particle size and the influence of anatomical ocular barriers on administration in the suprachoroidal space.

Whole rabbit eyes (Pel-Freez Biologicals, Rogers, AR), pig eyes (Sioux-Preme Packing, Sioux Center, IA) and human eyes (Georgia Eye Bank, Atlanta, GA), all with attached optic nerves, are They were shipped on ice and stored in humid conditions at 4 ° C for up to 3 days. Prior to use, the eyes were allowed to come to room temperature and any fat or connective tissue was removed to leave the sclera exposed.

Hollow microneedles were fabricated from borosilicate micropipette tubes (Suiter Instrument, Novate CA), as previously described (J. Jiang, et al., Pharm. Res. 26: 395-403 (2009)). FIG. 7A shows a comparison of the hollow microneedle compared to the tip of a 30 gauge hypodermic needle (scale = 500 pm). A custom pen-type device was manufactured with a screw cap to position the

<img file="MX360969B_D0036.tif" />

IMP

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY micro-needle and allow precise adjustment of its length. The device was attached to a micropipette gnpnrfode (MMP-KIT, World Precision Instruments, Sarasota, FL) with tubing that was connected to a cylinder of carbon dioxide gas for injection pressure application. The support was attached to a micromanipulator (KITE, World Precision Instruments) which was used to control the insertion of the microneedle into the sclera.

FluoSpheres® modified with carboxylate (Invitrogen, Carlsbad, CA) were injected as a 2% by weight solids suspension of 20nm, 100nm, 500nm and 1000nm diameter particles. Tween 80 (Sigma-Aldrích, St. Louis. MO), at a final concentration of 0.5% by weight, was added to the suspension and sonicated prior to use. Sulforhodamine B (Sigma-Aldrich) was dissolved in Manks' Balanced Salt Solution (Medialech, Manassas, VA) to create a sulforhodamine solution of 10 ⁴ M. Barium sulfate particles (Fisher Scientific, Waltham, MA) measuring 1 pm in diameter were suspended in balanced salt solution (BSS Plus, Alcon, Fort Worth, TX) to form a 1.5 wt% suspension.

A custom acrylic mold, molded to fit an entire eye, was created to hold the eye steady and used for all experiments (FIG. 7B). A catheter was inserted through the optic nerve into the vitreous humor and connected to a BSS Plus bottle raised to a height to generate internal eye pressure (18 or 36 mm Hg). Suction was applied to a canal within the mold to hold the outer surface of the eye firm during insertion and manipulation of the microneedle. Each microneedle was pre-filled with a desired volume of material to be injected. The microneedle was placed in the support device with a determined needle length, attached to the micromanipulator and connected to the constant pressure source. The microneedles were inserted perpendicularly into the scleral tissue 5-7 mm from the posterior limbus. A set pressure was applied to induce injection. They waited thirty seconds to see if the solution injection started. If injection occurred, the pressure was raised immediately after injection of the specific volume. If visual observation of the injected material showed localization in the suprachoroidal space, the injection was considered a success. If the injection had not started within that time period, the applied pressure stopped and the needle retracted. This was not considered a successful administration.

<img file="MX360969B_D0037.tif" />

The eyes from which images were to be obtained by microscopy were removed from the preparation minutes after administration was completed. The eyes were placed in acetone or isopentane, being kept on dry ice or liquid nitrogen, causing the eye to freeze completely within minutes of placement. The frozen eye was removed from the fluid and cut by hand using a razor blade to obtain images of the injected material. Imaging was carried out using a stereo microscope using brightfield and fluorescent optics (model SZX12, Olympus America Center Valley, PA). Portions containing the sclera, choroid, and retina were placed in Optimum Cut Temperature media (Sakura Finetek, Torrance, CA) and frozen in dry ice or liquid nitrogen. These samples were cryosected 10-30 pm thick (Microm Cryo-Star HM 560MV, Walldorf, Germany) and images were obtained by brightfield and fluorescent microscopy (Nikon E600, Melville, NY) to determine the location of the material. injected into the eye. A collage was made with the images using Adobe Photoshop software (Adobe Systems, San José, CA).

The pig eyes used for the microcomputerized tomography images did not freeze after injection. Instead, the pig's eyes were injected with barium sulfate suspension and stabilized in a 30mm diameter sample tube and scanned in air using a Scanco pCT40 computer cone beam system (Scanco Medical AG, Brüttisellen, Switzerland) at 30 pm isotropic voxel size E = 55 kVp, I = 145 pA and integration time = 200 ms. Through a convolution back projection algorithm based on the techniques of Feldkamp et. to the. (J. Opt. Soc. Am. A-Opt. Image Sci. Vis. 1: 612-619 (1984)), raw data were automatically reconstructed to generate 2D gray scale tomograms. Global segmentation values ​​(Gaussian sigma, Gaussian support, and threshold) were chosen for the region of enhanced contrast as well as overall eye tissue. The grayscale tomograms were stacked, and 3D binarized images were produced applying the optimal segmentation values ​​(one image for the entire eye and one for the region into which contrast agent was injected). These images were overlaid using Scanco image processing language to demonstrate the relative 3D position of the enhanced contrast region within the entire eye.

IMPI

<img file="MX360969B_D0038.tif" />

Example 1: Administration of a model compound to the suprachoroidal space using a hollow microneedle.

Fluorescent red sulforhodamine B was used as a model compound and injected into pig eyes ex vivo using a single hollow microneedle inserted just at the base of the sclera in order to target the suprachoroidal space. A bright field microscopic image of the sagittal cross section of an untreated pig's eye, shown in FIG. 8A and 8B (scale bar: 500 pm), taken both before and after injection of 35 pL of sulforhodamine B. Normal eye tissue (FIG. 8A) can be distinguished to identify the sclera, choroid, retina, and vitreous humor. After injection of the model compound (FIG. 8B), the sulforhodamine solution can be seen just below the sclera and over the choroid in the suprachoroidal space, confirming that the solution was injected and spread within the suprachoroidal space from the site initial injection. It was possible to inject volumes up to 35 pL without spillage, but larger volumes came out of openings in the surface of the eye where the vortex veins would be found in vivo. However, subsequent experiments in pigs and rabbits in vivo demonstrated suprachoroidal administration of up to 100 pL without loss through these openings (data not shown).

Example 2: Administration of particles in the suprachoroidal space using hollow microneedles

Particles with diameters of 500nm or 1000nm were injected into the suprachoroid space of rabbit, pig, and human eyes ex vivo and images were obtained to assess the distribution and location of the particles just below the sclera. The sclera (1), choroid (2) and retina (3) were identified in a fluoroscopic image of a pig's eye cryosection without injection into the suprachoroidal space (FIG. 9A, Scale bar: 500 pm). Fluoroscopic images of cryosections of a rabbit eye were taken after injection of 500nm particles in the axial plane and a collage was made with the images to form a panoramic view (FIG. 9B, Scale bar: 500 pm). The spread of fluorescent particles (which

IMPI

<img file="MX360969B_D0039.tif" />

they appeared as bright white regions in the images) be ODséiSzó at the side of the eye's equator in a thin layer just below the sclera. A volume of 15 pL was injected and, in this particular cross section taken in the plane of the insertion site, the injection had spread approximately 20nm, corresponding to about 36% of the eye circumference.

Fluoroscopic images of pig and human eye cryosections were taken in the sagittal directions so that the images showed the front of the eye to the right and the back of the eye to the left (FIG. 9C and 9D, respectively) . These images show the ability of the microinjected particles (which appear in bright white) to spread in the suprachoroidal space both towards the front and back of the eye from the injection site. In these experiments, a single microneedle delivered 30 pL of a 2% by weight suspension of particles into the suprachoroidal space of both species. Losses at the vortex vein openings away from the injection site were observed in a similar manner to that observed with sulforhodamine injections.

The inserts in these images show enlarged views of the microneedle insertion site. In each case, the insertion site within the sclera was filled with particles. In the case of the pig (FIG. 9C) and the human (FIG. 9D), the retina was still attached and visible, and it was clear that the microneedle had not penetrated the retina. In the case of the rabbit (FIG. 9B), the retina was separated during the cryosection procedure and was not visible. These results confirmed that a microneedle had the ability to target the suprachoroidal space of rabbit, pig, and human eyes to deliver particles up to 1000 nm in diameter. The results further confirmed that these particles spread circumferentially from the injection site in all directions within the suprachoroidal space.

Microcomputed tomography (pCT) was used to obtain images of the circumferential spread and the location of the injected material in the suprachoroidal space in three dimensions using a non-invasive method. After injecting 35 pL of 1 pm diameter barium sulfate contrast agent particles into the

<img file="MX360969B_D0040.tif" />

IMPI suprachoroidal space of a pig's eye, cross-sectional images showed Has particles distributed as a thin white stripe surrounding the outer edge of the eye below, ie just below the sclera (FIG. 10A). This profile is characteristic of suprachoroidal administration and similar to the results of fluorescent imaging. Three-dimensional reconstruction of these cross-sectional images showed the spread of the particles in the posterior segment of the eye (FIG. 10B, Scale bar: 5 mm). The spread of the particles was approximately within a radius of 5 mm, although they were distributed asymmetrically around the injection site, and covered an area of ​​approximately 70 mm.² (representing 7% of the surface area of ​​the back of the eye). This further confirmed the ability of the microneedles to spread the particles over a significant portion of the posterior segment of the eye targeting the suprachoroidal space.

Example 3: Effect of parameter operation on particle delivery to the suprachoroidal space

Particles of 20,100, 500 and 1000 nm in diameter were injected into pig eyes ex vivo using a range of different microneedle lengths and injection pressures to determine the success rate of suprachoroidal administration. A tentative injection was considered to be either completely successful (complete injection of 25 pL of particle suspension into the suprachoroidal space) or completely failed (inability to inject at all). No partial injections were observed. The effect of injection pressure and microneedle length on the success rate of suprachoroidal particle delivery is shown for particles of 20nm (FIG. 11A), 100nm (FIG. 11B), 500nm (FIG . 11C) and 1000 nm (FIG. 11D) in pig eyes.

The success rate increased with higher injection pressure and with a longer microneedle length (ANOVA, p &lt;0.05). For the 20nm particles (FIG. 11A), 100% successful injections were achieved using a 250 kPa pressure with all microneedle lengths. For 100 nm particles (FIG. 11B), the pressure effects were stabilized similarly at 250 kPa and 100% success was achieved with all micro needle lengths except the shortest (700 pm). For the largest particles (500 and 1000 nm) (FIG. 11C and 11D, respectively), the effects of pressure are

IMPÍ

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX360969B_D0041.tif" />

They generally stabilized at 300 kPa and the success rate decreased significantly for shorter microneedles. Without sticking to any theory, short-length microneedles are believed to inject into the sclera, so that the particles would be forced through a portion of the sclera to reach the suprachoroidal space.

The smallest particles (20 and 100 nm) can be more easily introduced through a portion of the sclera to reach the suprachoroid space, because the space of the collagen fiber lumps in the sclera is at 300 nm. The larger particles (500 and 1000 nm), however, present a greater difficulty in crossing this anatomical barrier, therefore, the injection pressure becomes a more important parameter and the injection success rate decreases significantly.

A statistical comparison of injection rates of particles of different sizes with different microneedle lengths was made using ANOVA and is summarized in the following table.

<img file="MX360969B_D0042.tif" />

Significance was considered to be p &lt;0.05 and was indicated with an asterisk (*).

<td>Lenght of Microneedle</td><td>20 vs 100 nm</td><td>100 vs 500 nm</td><td>500 vs 1000 nm</td><td>20 vs 1000 nm</td>

<td>700 pm</td><td> 0.02*</td><td> 0.02*</td><td> 0.09</td><td> 0.02*</td>

<td>800 pm</td><td> 0.37</td><td> 0.00*</td><td> 0.10</td><td> 0.01*</td>

<td>900 pm</td><td> 0.18</td><td> 0.03*</td><td> 0.18</td><td> 0.03*</td>

<td>1000 pm</td><td> 0.18</td><td> 0.37</td><td> 0.21</td><td> 0.18</td>

Statistical analysis showed that with a microneedle length of 700 pm, where most of the sclerotic tissue must be traversed to reach the suprachoroidal space, the success rate was highly dependent on particle size. Using 800 and 900 pm microneedles, particles smaller than the collagen fiber space (20 and 100 nm) behaved similarly and particles larger than the collagen fiber space (500 and 1000 nm) were also They behaved similarly, but there was a significant difference between the 100nm and 500nm particles. The longest microneedles (1000 pm), which probably reached the base of the sclera, do not show a significant dependence on particle size, suggesting that it was no longer necessary to overcome the collagen barrier in the sclera.

Without sticking to any theory, the suggested 20 and 100nm particles below can propagate within the sclera as well as within the suprachoroidal space, while the 500 and 1000nm particles should be located exclusively in the suprachoroidal space. Propagation of 20nm particles (FIG. 12A) was compared to propagation of 1000nm particles (FIG. 12B) under identical conditions. As expected, the smallest particles exhibited significant spread in the sclera, as well as in the suprachoroid space. In contrast, the larger particles were mainly relegated to the suprachoroidal space and largely excluded from the sclera. This location of large particles was consistent with the results shown in FIG. eleven.

<img file="MX360969B_D0043.tif" />

IMPI

MEXICAN INSTITUTE K DS THE PROPERTY J

INDUSTRIAL ^ &lt;¿7

Therefore, the 20 and 100 nm particles were safely injected using a minimum microneedle length of 800 pm and a minimum pressure of 250 kPa. To administer 500 and 1000 nm particles, a minimum microneedle length of 1000 pm and a minimum pressure of 250-300 kPa were required.

Example 4: Effect of infraocular pressure on the administration of particles to the suprachoroidal space

Intraocular pressure (IOP) is the internal pressure inside the eye that keeps the eye inflated. Provides back pressure that can counteract injection pressure. To assess the effect of intraocular pressure on particle delivery to the suprachoroidal space, 1000 nm particles with two different levels of IOP, 18 and 36 mmHg, were injected. The effect of injection pressure and microneedle length on the success rate of suprachoroidal administration of 1000nm particles with simulated IOP levels of 18mmHg and 36mmHg are shown in FIG. 13A and FIG. 13B, respectively. The administration success rate generally increases with an increase in IOP. In particular, with a normal IOP, no particles were administered with the lowest injection pressure (150 kPa) or using the shortest microneedles (700 pm) and only the longest microneedles (1000 pm) achieved an index of 100% Success with the highest injection pressure (300 kPa) (FIG. 13A). In contrast, at high IOP, the particles were sometimes administered at the lowest injection pressure level and using the shortest microneedles, and a 100% success rate was achieved using both the 900 and 1000 pm microneedles with the highest injection pressure (FIG. 13B).

Without sticking to any theory, it is believed that the main effect of elevated IOP is to make the sclera surface firmer, reducing surface deviation during microneedle insertion and thereby increasing the depth of penetration in the sclera for a microneedle of a certain length. Although the depth of the microneedle insertion was not measured directly, these results suggested that the microneedle insertion could be more effective with a high IOP because it is inserted deeper into the sclera and thus increases the index of injection success.

<img file="MX360969B_D0044.tif" />

<img file="MX360969B_D0045.tif" />

ΙΜΡϊ

Mexican Institute of Industrial Property

Example 5: Administration of a model compound to the suprachoroid space in live animal models

The administration of a fluorescent molecule (sodium fluorescein) in the suprachoroidal space was evaluated using rabbits according to approved experimental protocols in live animals. A one-dimensional scan of the eye (through line of sight) was taken after the first five minutes of injection to determine the dispersion of the fluorescent molecule in the eye (FIG. 14). The "y" axis indicates the fluorescent intensity (ie, the concentration) and the x "axis represents the position in the eye from the front (160) to the back (0). Therefore, the results illustrate that within the first 5 minutes after injection, fluorescein had already flowed through the suprachoroidal space into the back of the eye and something had remained at the initial insertion site.

Similar images were taken to assess the rate of fluorescein clearance from the suprachoroidal space over time (FIG. 15). Fluorescent intensity was measured in two regions of the eye (the suprachoroidal space and the mid region of the vitreous humor) over time. The results illustrate that the volume of the injected material remains in the suprachoroidal space without passing into the mid-vitreous region and that the material substantially left the suprachoroidal space after 24 hours.

Example 6: Administration of particles in the suprachoroidal space in live animal models

Experiments were also carried out on live animals to evaluate the administration of particles in the suprachoroidal space. Fluorescent particles having a diameter of 20nm and 500nm were injected into rabbit eyes and the fluorescent intensity was evaluated to determine the amount of time that the particles remained in the two regions of the eye (the suprachoroidal space and the middle region of the vitreous).

<img file="MX360969B_D0046.tif" />

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7 INSTITUTO MEXICA NP

CELA I'XOTtXIJnl · industrial

The smallest particles (FIG. 16) were administered correct-on-the.region.-, suprachoroidal and remained in the suprachoroidal space for at least 35 days. The largest particles (FIG. 17) were successfully administered in the suprachoroidal region and remained in the suprachoroidal space for at least 24 days.

In particular, both the smallest and largest particles were well located as indicated by the low level of fluorescence in the mid-vitreous region.

The publications cited herein and the materials for which they are cited are specifically incorporated by this reference. Modifications and variations of the methods and devices described herein will be apparent to those skilled in the art from the detailed description above. Such modifications and variations are intended to be within the scope of the appended claims.