Masking method for coating a microneedle array

This application claims priority to US Provisional Patent Application No. 60 / 629,209 filed on November 18, 2004, which is incorporated herein in its entirety.

The present invention relates to a method for coating a microneedle array.

Even with approved chemical enhancers, only a limited number of molecules with proven therapeutic value can be transported through the skin. The main barrier to the transport of molecules through the skin is the stratum corneum (the outermost layer of the skin).

Devices containing sequences of relatively small structures are sometimes referred to as microneedles or micropins, which are disclosed for use in connection with the delivery of therapeutic agents and other substances through the skin and other surfaces. The device is typically pressed against the skin for the purpose of puncturing the stratum corneum so that therapeutic agents and other substances pass through the stratum corneum and into the tissues beneath it.

Microneedle devices with fluid reservoirs and conduits through which therapeutic material is delivered to the skin have been proposed, but such as the ability to create very fine channels that are reliably usable for fluid flow. Well, there are still many drawbacks to this system.

Microneedle devices with a dry coating on the surface of the microneedle array have desirable features compared to fluid reservoir devices. This device is generally simpler and can inject therapeutic material directly into the skin without the need to provide reliable control of fluid flow through very fine channels in microneedle devices. it can.

<p> The ability to provide a consistent coating at one or more desired locations on the microneedle array is an important feature for microneedle devices with dry coatings. Despite the many well-known methods of providing dry coatings on a flat surface in general, coating of microneedle arrays poses difficulties due to the high surface irregularities inherent in any array design.</p>

<p> It has been found that by masking the substrate of the microneedle array, the drying rate and coating position of the coating fluid can be adjusted and controlled.</p><p> The present invention provides, among other things, a substrate and a microneedle array having at least one needle; the substrate is at least partially covered with a masking layer, and at least one needle is at least partially exposed. A method of coating a microneedle array comprising the steps of providing a removable masking layer on the microneedle array so that it remains; and the step of applying a coating material to at least a portion of the exposed portion of the microneedle array. provide.</p><p> The invention will be further understood by those skilled in the art by considering the rest of the disclosure, including a detailed description of the invention and the appended claims.</p><p> As used herein, certain terms will be understood as having the meanings set forth below.</p><p> As used herein, an "array" includes one or more structures that can be punctured in the stratum corneum to facilitate transdermal delivery of therapeutic agents or through the skin or to facilitate sampling of fluids into the skin. Refers to the medical device described.</p><p> A "microstructure", "microneedle" or "microarray" is a specific array associated with an array in which it is possible to puncture the stratum corneum to facilitate transdermal delivery of therapeutic agents or sampling of fluids through the skin. Refers to a microstructure. As an example, microstructures can include needle or needle-like structures, as well as other structures capable of piercing the stratum corneum.</p><p> The features and advantages of the present invention will be understood by considering the detailed description of preferred embodiments and the appended claims. These and other features and advantages of the invention are described below in connection with various exemplary embodiments of the invention. The abstracts of the invention as described above are not intended to explain each or all of the disclosed embodiments of the invention. The drawings and detailed description below are specifically intended to illustrate exemplary embodiments.</p><p> Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.</p>

An embodiment of the method of the present invention is shown in FIGS. 1 to 3. FIG. 1 shows an uncoated microneedle array 200 having a substrate 220 and microneedles 210 projecting from the substrate 220. The masking fluid 230 is applied to the microneedle array 200 (shown in FIG. 2), thereby coating the substrate 220. The coating fluid 235 is then applied (shown in Figure 3A). The coating fluid 235 is preferably applied so that it does not interfere with the masking fluid 230. The coating fluid 235 preferably forms a separate layer above the masking fluid 230. Partially evaporate the coating fluid as shown in Figure 3B. As shown in FIG. 3C, the coating fluid is completely evaporated, leaving a dry coating 240 on the tip of the microneedle 210. Partially evaporate the masking fluid 230 as shown in Figure 3D. Completely evaporate the masking fluid 230, as shown in FIG. 3E.

It should be understood that the continuous evaporation described above does not need to be carried out in such a discontinuous, stepwise manner. That is, both the coating fluid and the masking fluid may be evaporated simultaneously so that the level of the masking fluid can be reduced as shown in FIG. 3B before all of the coating fluid is evaporated. Similarly, the dry coating shown in FIG. 3E may take any of many different shapes. As shown, it may be a thin layer coating on the top of each microneedle, but it may form more droplet shape at the tip, or similarly partial the bottom of the microneedle. May be coated. To adjust the position of the dry coating, it is desirable to adjust the relative rate of evaporation and / or mixing of the masking fluid and the coating fluid. The dry coated portion may be adhered to the substrate.

The masking fluid does not need to uniformly coat the substrate as shown in FIG. 2, but may form a meniscus due to the surface tension effect as shown in FIG. Although this meniscus is shown as a concave shape, it may have a convex shape. The shape of the meniscus is a number of factors, including the type of masking fluid, the type of substrate and microneedle material, the size of the microneedles, the spacing between the microneedles, and the surface treatment of either the microneedles and / or the substrate. May be adjusted by.

In one embodiment (not shown), the masking fluid may first be applied to cover the entire microneedle. The masking fluid may then be partially evaporated or partially removed so that the microneedles to which the coating material is applied are partially exposed. The coating material may then be applied after the microneedles have been exposed, or the coating material may be applied over the masking fluid while the masking fluid is still completely covering the microneedles. Once the masking fluid has been removed and the array exposed, the coating material is then applied to the exposed portion of the microneedle array.

A wide variety of masking fluids are selected, and the type of substrate and microneedle material, the size of the microneedles, the spacing between the microneedles, the surface treatment of either the substrate and / or the microneedle, the coating fluid It can depend on a number of factors, including the type of treatment, any therapeutic agent contained within the coating fluid, and the intended application of the dry coated microneedle array.

In one aspect, the density of the fluid in the masking layer is higher than the density of the coating solution. Microneedle arrays are typically placed in an orientation in which the substrate is supported from the bottom and the coating fluid is applied from the top. In this case, the higher density of the fluid in the masking layer can help prevent or minimize mixing of the masking fluid and the coating solution. In one aspect, the masking fluid is substantially immiscible with the coating fluid. It must be understood that the masking and coating fluids do not have to be completely miscible due to their substantial immiscibility, but the relative solubility of one on the other is relatively small and insignificant. .. For example, the solubility of the masking fluid in the coating fluid (or vice versa) is less than about 5% by weight, preferably less than about 1% by weight. In one embodiment, the one or more solutes contained in the coating fluid are substantially insoluble in the masking fluid. It should be understood that the solubility of one or more solutes is relatively small and insignificant, although substantially insoluble does not require one or more solutes to be completely insoluble. For example, the solubility of the coating fluid solute in the masking fluid is less than 10%, and preferably less than 1%, of the solubility of the solute in the coating fluid.

In one aspect, the masking fluid preferably has a vapor pressure lower than the vapor pressure of the coating fluid. That is, the volatility of the fluid in the masking layer is lower than the volatility of the coating fluid. This may help substantially evaporate the coating fluid before the masking fluid evaporates. In one embodiment, the volatility or vapor pressure may be determined and compared at the drying temperature that both the masking fluid and the coating fluid undergo. Drying of the masking fluid and / or coating fluid may be performed at any suitable temperature. For example, drying may be performed under ambient conditions (eg, about 20 ° C to 23 ° C) under conditions that are essentially unrestricted to evaporation, in addition to being provided naturally by typical atmospheric conditions. Alternatively, the drying rate can be varied by holding the array in an environment saturated with masking fluid and / or coating fluid vapor, partially or completely. This can be done by adding vapor directly to the environment surrounding the array, or by placing the array in a partially closed environment to accumulate vapor in the area surrounding the array. For example, the array may be held in a closed Petri dish during drying. Yet another option is to hold the array in a drying oven that can combine temperature increase and / or air flow to accelerate the drying rate. Yet another option is to hold the masking fluid at a different temperature (eg, lower temperature) than the coating fluid to facilitate evaporation due to the difference between the two fluids. In one option, it is desirable to adjust the vapor pressure of the masking fluid so that it evaporates at about the same rate as the coating fluid or at a faster rate than the coating fluid. Such adjustments allow, for example, full side coating of microneedles or partial coating of substrate, which is desirable depending on the intended use of the dry coated microneedle array. In another embodiment, the coat

Fluorinated solvents such as hydrofluoroethers, hydrofluoroalkanes, perfluoroalkanes and other perfluorinated compounds have a relatively high density and are relatively miscible with water and / or many conventional organic solvents. Therefore, it may be particularly suitable for use as a masking fluid. An example of a suitable fluorination solvent is 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6,6-dodecafluoro-2-trifluoromethyl-hexane (3M). 3M Company (3M Co.), 3M (Registered Trademark) Novec (Registered Trademark), Engineered Fluid (available as Engineered Fluid) HFE-7500), Ethylnonafluoroisobutyl ether and Ethylnonafluorobutyl ether (3M Company (3M)) Co. to 3M (registered trademark) Novec (registered trademark) Engineered Fluid (a mixture available as HFE-7200), FC-43 FLUORINERT (registered trademark) Electronic Liquid (registered trademark) Electronic Liquid) (a mixture of primary 12-carbon perfluoro compounds available from 3M Co.), as well as FC-5312 Fluorinert® Electronic Liquid (3M Company (3M)). A mixture of primary 15 carbon perfluoro compounds available from Co.)). For example, if the coating solution comprises a low density organic solvent such as hexane or heptane, water may be suitable as a masking fluid.

The coating solution comprises a carrier fluid or solvent and at least one dissolved or dispersed coating material that ultimately results in a dry coating on the microneedle array. The carrier fluid or solvent must be selected so that the coating can dissolve or disperse the intended material. The dispersed material may be in the form of a suspension, i.e., particles dispersed or suspended in a carrier fluid or solvent. Examples of suitable carrier fluids or solvents include water, ethanol, methanol, isopropanol, ethyl acetate, hexane and heptane. The coating solution may contain additional excipients, including, for example, viscosity modifiers, stabilizers, surfactants and other additives. Examples of suitable additional excipients include sucrose, trehalose, raffinose, lactose, ovalbumin, potassium citrate, polyvinylpyrrolidone, polyoxyethylene sorbitan ester (ie, polysorbate) and hydroxyethyl cellulose. In one embodiment, the coating solution preferably wets the masking layer, i.e. it spreads relatively uniformly across the masking layer. Such spread preferably leads to a relatively uniform application of the coated material to the microneedle array. Alternatively, the surface properties of the coating solution and / or masking fluid control the spread amount of the coating solution, thereby allowing the application of a controlled amount of coating material at a particular location on the microneedle array. It may be adjusted. Evaporation of the carrier fluid may occur under ambient conditions or may be regulated by changing the temperature or pressure of the ambient atmosphere of the microneedle array. Evaporation conditions are preferably selected to avoid decomposition of the coating material.

After the addition of the first masking fluid to the microneedle array, the second masking fluid may optionally be added. For example, a hydrofluoroether masking fluid may be added to the array followed by ethanol to prepare a masking layer. Then, the coating solution is then added as described above. The second masking fluid can assist in changing the relative evaporation rate or adjusting the surface tension between different fluids.

In another embodiment, the coating may be applied directly as a solid, as in the case of spray coating. In this case, the carrier fluid is optional or unnecessary. In another embodiment, the masking layer may be in the form of a solid or semi-solid layer. The masking layer in the form of the masking film 300 is shown in FIG. Such a film may be, for example, a thin polymer film. It is perforated by the microneedle to a predetermined height so that only the tip of the microneedle is exposed. As shown in FIG. 6, the coating solution may be applied to the needle tip. The coating solution may be applied as a continuous layer as shown in FIG. 3A.

The dry coating material is adhered onto the microneedle array. In one embodiment, the dry coating material is preferentially adhered onto the microneedles. Priority attachment means that the amount of dry coating per unit surface region is greater on the microneedles than on the substrate. More preferably, the dry coating material is preferentially attached on or near the tip of the microneedle. In some cases, more than half by weight, sometimes more than 90%, and occasionally more than 95% of dry coating material is adhered on the microneedles. In some cases, the dry coating is preferentially placed in the upper half of the microneedle, i.e. the microneedle portion away from the substrate. In one embodiment, substantially no dry coating material is attached on the substrate, i.e., substantially all dry coating material is attached on the microneedles. In one embodiment, substantially all dry coating material is adhered onto the upper half of the microneedles. By virtually all, it must be understood that trace amounts of dry coating material, such as less than about 5% by weight, preferably less than about 1% by weight of dry coating material, do not adhere to the top half of the microneedles. .. The thickness of the dry coating material may vary depending on the location of the microneedle array and the intended application of the coated microneedle array. The thickness of the dry coating is typically less than 50 microns, often less than 20 microns, and sometimes less than 10 microns. With respect to the thickness of the coating, it is desirable to be smaller near the tip of the microneedle so as not to interfere with the ability of the microneedle to effectively puncture the skin.

In one embodiment, different portions of the coating material may be preferentially attached at different positions on the microneedle array. For example, if the coating material comprises a pharmaceutically effective substance (eg, an antigen), it is desirable to preferentially attach the pharmaceutically effective substance on or near the tip of the microneedle. In some cases, more than half by weight, sometimes more than 90%, and occasionally more than 95% of pharmaceutically effective substances are attached on the microneedles. In some cases, the pharmaceutically effective substance is preferentially placed in the upper half of the microneedle, i.e. the microneedle portion away from the substrate. In one embodiment, substantially no pharmaceutically effective substance adheres to the substrate, i.e., substantially all pharmaceutically effective substances adhere to the microneedles. In one embodiment, substantially all pharmaceutically effective substances are attached to the upper half of the microneedles. By virtually all, trace amounts of pharmaceutically effective material, such as less than about 5% by weight, preferably less than about 1% by weight of pharmaceutically effective material, should not adhere to the upper half of the microneedle. Must be understood.

The dry coating material remains solid or semi-solid after removal of the carrier fluid. However, when referring to a dry coating material, it should be understood that a relatively small amount of carrier fluid and / or masking fluid may remain in the resulting dry coating material. For example, if the carrier fluid comprises water, the resulting dry coating will typically be about 0.1-30% by weight water, often about 1% to 20% by weight water, and sometimes about 1-10% by weight. May contain% by weight of water.

When a masking film is utilized, it is preferably a liquid impervious film, and preferably a polymeric film. Examples of suitable polymer films include polypropylene, polyethylene or polyethylene terephthalate. The masking film may have a surface coating such as a silicone or fluorochemical release coating. This repels the aqueous coating fluid from the masking film and beads the coating solution onto the exposed needle tip. Alternatively, the masking film may have a hydrophilic coating. It can repel the organic coating fluid from the masking film.

In one embodiment, the masking film is removed after the carrier fluid is evaporated, leaving a dry-coated microneedle array as shown in FIG. 3E. Alternatively, the masking film may be left in place and a dry coated microneedle array with the masking film as shown in FIG. 6C can be applied directly to the skin surface. In another option (not shown), the carrier fluid can be evaporated and then the film can be pushed downwards into contact with the substrate. Arrays coated with masking film may have additional utility, as described in US Patent Application Publication No. 2003/0135161, which is incorporated herein by reference. The masking film can be perforated by the microneedle array by any suitable method, including simultaneous delivery of force and ultrasonic energy and other methods described in US Patent Application Publication No. 2003/0135161.

In one embodiment, the two immiscible solutions may be agitated or agitated to form a temporarily uniform emulsion applicable to the microneedle array. After application to the microneedle array, the emulsion can then be phase separated, leaving a fluid layer that acts as a masking layer with respect to the substrate and a fluid layer that acts as a coating solution. These layers may then be evaporated to leave the dry coating film as described above.

In another embodiment, the masking layer may be a semi-solid or solid layer that can be converted to a liquid and then removed. Examples of suitable masking layers are temperature-reactive gels, electrorheological fluids, reversible gels, eg silica or polymer gels that are sensitive to either pH or ions, or any other suitable temporary or Examples include reversible gels.

A typical temperature-reactive gel useful as a masking layer is a gel formed from propylene oxide-ethylene oxide block copolymers, such as Pluronic® F-77 (available from BASF). A microneedle array of aqueous gels with a solid content of approximately 1% by applying a solution of the temperature-reactive propylene oxide-ethylene oxide block copolymer to the substrate and then heating the array to a temperature above 34 ° C to form a gel. May be prepared above. The coating solution is applied to the exposed microneedles and then dried. The dry-coated array may then be cooled to room temperature, thereby returning the gel to a liquid state and removing it from the array. Other examples of temperature-reactive gels can also be found in US Pat. No. 4,474,751, which is incorporated herein by reference.

A microneedle array substrate for a low solid content hydrogel solution that gels upon exposure to salts as described in U.S. Pat. Nos. 5,340,572 and 5,192,535, which are incorporated herein by reference. May be applied to provide a masking layer. The salt solution may then be added to the hydrogel solution to gel the hydrogel solution. The coating solution may then be applied to the gelled masking layer and dried. This leaves a dry-coated microneedle array on the exposed portion of the microneedles. The pH or ionic content of the gelled masking layer may then be altered to return the gel to a liquid state that can be easily removed from the microneedle array.

A charged colloidal fluid may be applied as a masking layer. Upon application of the electric field, the colloidal fluid can form a gel that can act as a semi-solid masking layer. The coating solution is then applied to the gelled masking layer and dried, thereby leaving a dry-coated microneedle array on the exposed portion of the microneedles. The electric field can then be removed and the masking layer can be converted to a liquid state. This liquid can be removed from the array and / or evaporated.

In another embodiment, the masking layer may be a solid layer comprising a frozen fluid such as ice. The coating solution is applied and dried, leaving a dry-coated microneedle array on the exposed portion of the microneedles. The ice layer is then warmed to liquid water that can be removed by any conventional means.

In any of the above embodiments, immersion, brushing, drop coating, precision volumetric comprising to apply the masking fluid to the array substrate or to apply the coating solution to the masked microneedle array. ), Any of many conventional coating methods may be used, including gravure coating and spray coating. In one embodiment, the coating solution and / or masking solution may be applied as a metered amount of one or more drops spread across the array substrate.

In one embodiment, the microneedle array shown in FIG. 3E may be applied to the skin surface in the form of a patch shown in more detail in FIG. FIG. 7 shows a microneedle device comprising patch 20 in the form of a combination of array 22, pressure sensitive adhesive 24 and backing 26. Part of the array 22 shows the microneedles 10 projecting from the surface 14 of the microneedle substrate. The microneedles 10 may be arranged in any desired pattern or may be randomly dispersed on the surface of the microneedle substrate 14. As shown, the microneedles 10 are arranged in evenly spaced rows. In one embodiment, the array of the invention is about 0.1 cm.²Larger, about 20 cm²Less than, preferably about 0.5 cm²Larger, about 5 cm²It has a surface area facing less than the end. In one embodiment (not shown), part of the substrate surface 14 of patch 20 is unpatterned. In one embodiment, the unpatterned surface has an area greater than about 1 percent and less than about 75 percent of the total area of the device surface facing the patient's skin surface. In one embodiment, the unpatterned surface is approximately 0.10 square inches (0.65 cm).²) Larger, about 1 square inch (6.5 cm)²) Has an area less than. In another embodiment (shown in FIG. 7), the microneedles are placed on substantially the entire surface area of the array 22.

Microneedle devices useful in various embodiments of the invention may include any of a variety of configuration, such as those described in the following patents and patent applications, incorporated herein by reference. One embodiment for a microneedle device comprises the structure disclosed in US Patent Application Publication No. 2003/0045837. The microstructure disclosed in this patent application is in the form of a microneedle having a tapered structure containing at least one channel formed on the outer surface of each microneedle. The microneedles may have a base extended in one direction. A channel in a microneedle having an elongated base can extend from one of the ends of the elongated base toward the tip of the microneedle. The channels formed along the sides of the microneedles may optionally end as short as the tips of the microneedles. The microneedle array may include a conduit structure formed on the surface of the substrate on which the microneedle array is located. Channels in the microneedles may be in fluid communication with the conduit structure. Another embodiment of the microneedle device comprises the structure disclosed in US Patent Application No. 10/621620, filed July 17, 2003, which is co-pending. This patent describes microneedles with a tapered shape with a truncated tip and a controlled aspect ratio. Yet another embodiment for microneedle devices comprises the structure disclosed in US Pat. No. 6,091,975 (Daddona et al.). This patent describes a blade-like microprotrusion for puncturing the skin. Yet another embodiment of the microneedle device is U.S. Pat. No. 6,313, It comprises the structure disclosed in specification 612 (Sherman et al.). This patent describes a tapered structure with a hollow central channel. Yet another embodiment of the microarray comprises the structure disclosed in WO 00/74766 (Gartstein et al.). This patent describes a hollow microneedle having at least one longitudinal blade on the upper surface of the tip of the microneedle.

Prior to applying the masking layer and coating material, one or more surfaces of the microneedle array may be modified by coating or surface primary treatment. For example, a thin layer of material may be applied to the entire surface of the array prior to applying the masking layer. Such coatings can alter the hydrophilicity or hydrophobicity of the array, thereby affecting the ability of the masking layer and / or coating solution to wet the array. Such coatings are such that the coating is partially or completely dissolved in the coating solution before the carrier solvent has completely evaporated, thereby leaving a dry mixture of the coating primary treatment material and the coating material applied thereafter. And may be partially or completely miscible. Examples of such coatings include polymer coatings, dry powders and amorphous glass.

Examples of suitable polymer coatings include polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, fluoropolymers and mixtures thereof. Such polymer coatings can be prepared on the array by applying a polymer solution (eg, aqueous solution or ethanol solution) to the array and evaporating the solvent, thereby leaving a dry polymer coating behind. Alternatively, the coating may be applied directly as a solid material, for example by the use of heat or plasma adhesion. Examples of dry powders include potassium aluminum sulfate dodecahydrate, aluminum hydroxide monohydrate, sucrose, trehalose and lactose. Examples of thin layers of material that are cured onto the array are plasma-attached diamond-like glass films, such as those described in US Pat. No. 6,881,538 (Haddad et al.), US Pat. No. 5,440,446. Applied by UV-polymerized acrylates, plasma-adhered fluoropolymers, such as those described in the specification (Shaw et al.), Or conventional coating methods such as spray coating or roll coating, followed by any suitable radiation. These include any other thin layer that is crosslinked using.

The surface of the microneedles may be changed by a surface primary treatment that simply changes the chemical functionality of the surface. Typical surface primary treatments include various plasma treatments capable of varying surface functionality. For example, the polycarbonate may be plasma treated with nitrogen plasma to produce amide functionality or plasma treated with oxygen plasma to produce carboxylate functionality. A combination of nitrogen and oxygen plasma treatments may be used to provide mixed surface functionality.

The coating solution may contain one or more biologically active materials, pharmaceutically effective substances and therapeutically active substances. In one embodiment, a drug (any agent) such as a vaccine, a microneedle device suitable for use in the present invention, through the skin in various transdermal deliveries, or into the skin for intradermal or topical treatment. May be used to deliver). In one embodiment, the macromolecular weight drug may be delivered transdermally. Increasing the molecular weight of a drug typically results in a decrease in unassisted transdermal delivery. Microneedle devices suitable for use in the present invention have utility for the delivery of macromolecules that are usually difficult to deliver by passive transdermal delivery. Examples of such macromolecules include proteins, peptides, nucleotide sequences, monoclonal antibodies, DNA vaccines, polysaccharides such as heparin and antibiotics such as ceftriaxone.

In another embodiment, a microneedle device suitable for use in the present invention improves transdermal delivery of small molecules that are difficult or impossible to deliver by passive transdermal delivery or It may have practicality to make it possible. Examples of such molecules include salt-type; ionic molecules, such as bisphosphonates containing sodium alendronate or sodium pamidronate; and molecules with physicochemical properties that do not contribute to passive transdermal delivery.

In another embodiment, a microneedle device suitable for use in the present invention is for improving molecular delivery to the skin, for example, in dermatological treatment, vaccine delivery, or in increasing the immune response of a vaccine adjunct. Can have practicality. Examples of suitable vaccines include influenza vaccine, lime disease vaccine, mad dog disease vaccine, sardine vaccine, mumps cold vaccine, varicella vaccine, natural pox vaccine, hepatitis vaccine, pertussis vaccine, ruin vaccine, diphtheria vaccine, encephalitis vaccine, etc. Yellow fever vaccine, recombinant protein vaccine, DNA vaccine, polio vaccine, therapeutic cancer vaccine, herpes vaccine, pneumonia vaccine, meningitis vaccine, whooping cough) vaccine, tetanus vaccine, typhoid vaccine, cholera vaccine, tuberculosis vaccine and combinations thereof. Thus, the term "vaccine" includes, but is not limited to, proteins, polysaccharides, oligosaccharides or antigens in the form of weakened or killed viruses. Additional examples of suitable vaccines and vaccine adjuncts are described in US Patent Application Publication No. 2004/0049150, the disclosure of which is incorporated herein by reference.

Microneedle devices are for immediate delivery where they may be applied and immediately removed from the application site, or they may be left in place for an extended period ranging from a few minutes to as long as a week. May be used. In one aspect, the extension period of delivery may be 1 to 30 minutes to allow complete delivery of the drug than would be obtained by application and immediate removal. In another embodiment, the extension period of delivery may be 4 hours to 1 week to result in release of the drug.

<u style="single">Total array content of tetanus toxoid by high performance liquid chromatography (HPLC)</u> Sample extraction solvents containing 50 mM potassium perchlorate, 50 mM potassium citrate, 20 mM sodium phosphate, 376 mM sodium chloride and 100 μg / mL bovine serum albumin were prepared. The HPLC sample solution was prepared by placing the array in a polypropylene cup, adding 1.0 mL of sample extraction solvent to the cup, capping the sample cup, and sonicating for 30 minutes.

Gradient Elution HPLC (Mobile Phase A): 0.2% (v / v) Perchloric Acid; Mobile Phase B: 10% Water, 88% acetonitrile, 2% Isopropanol, 0.2% Perchloric Acid (70%); Solvent Program: 0.00 Minutes, 22% B, 1.0 mL / min; 6.00 min, 58% B, 1.0 mL / min; 6.01 min, 100% B, 1.0 mL / min; 6.50 min, 100% B, 0.5 mL / min; 10.0 min, 0% B, 0.5 mL / min; Injection volume: 100 μL; Column: Zorbax 300SB-C8 (50 × 4.6 mm, 3.5 micron) was used to quantify the amount of tetanus toxoid in the HPLC sample solution.

Calibrate a non-adjuvanted tetanus toxoid (TT) vaccine (Aventis) against lyophilized TT primary standard (List Biologics) and use as a routine standard did. A calibration curve from about 1 μg-TT / mL to 28 μg-TT / mL was obtained using a working standard. The correlation coefficient for linear regression of the calibration curve was typically higher than 0.999. Tetanus toxoid content results are averages between 6 and 10 multiple doses.

<u style="single">Tetanus toxoid tip content by high performance liquid chromatography (HPLC)</u> The tetanus toxoid content on the tip of the microneedle was measured by immobilizing the toxoid on the substrate and at the appropriate location under the microneedle so that it would not be extracted into the HPLC sample solution. The microneedle array is placed on a flat surface with the needles facing up and 10 μL of oil-based polyurethane coating solution (Minwax® Fast-Drying Polyurethane). It was applied to the array and coated with the substrate of the array. The polyurethane was cured under ambient conditions for at least 3 hours. Arrays were then extracted and analyzed as described in the full content method.

<u style="single">Aluminum content by inductively coupled plasma (ICP)</u> For aluminum analysis by ICP, a 0.5 mL aliquot of the HPLC sample solution (above) was diluted to 5.0 mL with 4% nitric acid. The analysis was calibrated by using 1, 2, 4, 5, 6, 8 and 11 μg / mL aluminum standards. The correlation coefficient for linear regression of the calibration curve was typically higher than 0.999.

<u style="single">Enzyme-linked immunosorbent assay (ELISA)</u> Quantification of anti-tetanus toxoid IgG from rabbit serum was performed by ELISA. The solid phase is coated with tetanus toxoid and anti-tetanus toxoid IgG from rabbit serum samples is bound. The plate is washed and rabbit IgG is detected by anti-rabbit IgG-HRP conjugate. Assays were standardized for EP veterinary standard rabbit anti-tetanus toxoid BRP batch (Batch) 1 (EDQM-European Pharmacopeia Commission Catalog No. C2425600). 1000 Arbitrary Units (AU) from this ELISA is equivalent to 1 International Unit (IU). Unless otherwise stated, anti-tetanus toxoid IgG results are reported as a geometric average of 5 iterations.

<u style="single">Microneedle array</u> The microneedle array was prepared as follows. Squares concentrated on one side of the disc (1 cm)²) Microneedle array (37 x 37) partially patterned circular disc (2 cm area)², Thickness 1.02 mm) was prepared. The needles were regularly spaced at a distance of 275 microns between adjacent needle tips in a square pattern. The individual needles were in the shape of a pyramid at the square base with a height of 250 microns and a lateral length of 83.3 microns. The tip was truncated to have a flat square top with a lateral length of 5 microns. The array was injection molded and manufactured from polycarbonate according to the general description provided in WO 05/82596 (Lexan® HPS1R-1125, GE Plastics). , Massachusetts, Pittsfield (MA)). The center of the disc is then die-cut and a microneedle array with microneedles on approximately 90% of the surface on the pattern side of the disc (area = 1 cm).²) Was provided. The microneedle array had about 1200 microneedles.

<u style="single">Example 1</u> Prepare an aluminum mixture of 6.0 g aluminum sulphate dihydrate (Penta, USP grade), 0.24 g aluminum hydroxide monohydrate and 100 mL water and super until the solution is almost clear. Sonicated. Then a Six-Jet sprayer modified with a small volume reservoir, turbulence generator and array cage (Model 9306, TSI Inc., Shoreview, Minnesota). The aluminum mixture was spray coated onto the array for 1 minute using MN)). The coating rate was nominally 20 μg of aluminum per minute. The microneedle array was then placed on a flat surface with the needles pointing upwards. HFE-7500 3M® Novec® Engineered Fluid, 3-ethoxy-1,1,1,2,3,4,4,5,5,6,6, 6-Dodecafluoro-2-trifluoromethyl-hexane (3M Company (3M)) Co.), St. Paul, MN, Minnesota) was used as the masking fluid. Using a pipette, an aliquot (25 μL) of masking fluid was applied to the center of the array and spread across the array. The antigen coating formulation is the same part of the tetanus toxoid (Statens Serum). Institute) Lot 92-1, 888 Lf / mL) and prepared by mixing ethanol. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 16 μg. The antigen coating formulation and masking fluid were dried under ambient conditions for about 30 minutes to provide a dry antigen coating on the array. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a relatively smooth coating on the surface of the microneedles. The total tetanus toxoid array content measured by reverse phase HPLC was 18.2 μg (st.dev. = 1.2 μg). The aluminum content of the coated array as measured by ICP was 40 μg (st.dev. = 10 μg).

<u style="single">Example 2</u> The coated array was prepared according to the procedure described in Example 1, except that the aluminum mixture was spray coated onto the array for 3 minutes prior to application of the antigen coating formulation and a 13 μL aliquot of masking fluid was used. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a mass or sphere of material at or near the tip of the microneedle. The total tetanus toxoid array content measured by reverse phase HPLC was 19.1 μg (st.dev. = 1.0 μg). The aluminum content of the coated array as measured by ICP was 57 μg (st.dev. = 21 μg).

<u style="single">Example 3</u> With the following exceptions, coated arrays were prepared according to the procedure described in Example 1. An antigen-coated formulation was prepared by mixing 1 part tetanus toxoid, 3 parts water and 4 parts ethanol. A 13 μL aliquot of masking fluid was used. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 4 μg. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a relatively smooth coating on the surface of the microneedles. The total tetanus toxoid array content measured by reverse phase HPLC was 4.4 μg (st.dev. = 0.2 μg). The aluminum content of the coated array as measured by ICP was 13 μg (st.dev. = 6 μg).

<u style="single">Example 4</u> The coated array was prepared according to the procedure described in Example 3, except that the aluminum mixture was spray coated onto the array for 5 minutes prior to applying the antigen coating formulation. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a mass or sphere of material at or near the tip of the microneedle. The total tetanus toxoid array content measured by reverse phase HPLC was 4.7 μg (st.dev. = 0.4 μg). The aluminum content of the coated array as measured by ICP was 94 μg (st.dev. = 19 μg).

<u style="single">Example 5</u> The coated array was prepared according to the procedure described in Example 2, except that the aluminum mixture was spray coated onto the array for 5 minutes prior to applying the antigen coating formulation. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a relatively smooth coating on the surface of the microneedles. The total tetanus toxoid array content measured by reverse phase HPLC was 17.9 μg (st.dev. = 0.8 μg). The aluminum content of the coated array as measured by ICP was 65 μg (st.dev. = 8 μg).

<u style="single">Example 6</u> With the following exceptions, coated arrays were prepared according to the procedure described in Example 1. The aluminum mixture was spray coated onto the array for 3 minutes before applying the antigen coating formulation. An antigen-coated formulation was prepared by mixing 2 parts of tetanus toxoid, 2 parts of water and 4 parts of ethanol. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 8 μg. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a relatively smooth coating on the surface of the microneedles. The total tetanus toxoid array content measured by reverse phase HPLC was 7.6 μg (st.dev. = 0.7 μg). The aluminum content of the coated array as measured by ICP was 23 μg (st.dev. = 6 μg).

<u style="single">Example 7</u> With the following exceptions, coated arrays were prepared according to the procedure described in Example 1. An aluminum mixture was prepared with a ratio of 6.0 g of potassium aluminum sulphate dihydrate (Penta, USP grade), 0.06 g of aluminum hydroxide monohydrate and 100 mL of water. An antigen-coated formulation was prepared by mixing 1 part of tetanus toxoid with 1 part of water. A 13 μL aliquot of masking fluid was used. Before applying the antigen coating formulation, ethanol (13 μL) was applied to the center of the masking fluid using a pipette. The antigen coating formulation was then applied over ethanol. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 16 μg. Testing of the antigen-coated array by scanning electron microscopy (SEM) showed a smooth coating on the surface of the microneedles. The total tetanus array array content measured by reverse phase HPLC was 16.8 μg (st.dev. = 0.8 μg). The aluminum content of the coated array as measured by ICP was 15 μg (st.dev. = 3 μg).

<u style="single">In vivo anti-tetanus toxoid IgG and tetanus toxoid removal</u> Microneedle devices were prepared by adhering the antigen-coated arrays of Examples 1-2 to the adhesive backing. New Zealand white (New Zealand) array using an applicator as commonly described in U.S. Patent Application No. 60 / 578,651. White) Applied to female rabbits (N = 5). The literature is incorporated herein by reference. The applicator piston mass was 2.88 g, and the device was applied at a speed of 6.19 m / s. The abdominal area of each rabbit was closely clipped and shaved, being careful not to irritate the skin. One device was applied to each rabbit and kept in place for 20 minutes prior to removal. Fourteen days after the first application, each rabbit was applied with a second device (having the same coating as the first device) and again held in place for 20 minutes prior to removal. Serum samples were taken from each rabbit 21 days after the first application and analyzed for anti-tetanus toxoid IgG levels by ELISA. The results are summarized in Table 1. The remaining amount of tetanus toxoid in the array removed from the rabbit was tested by HPLC. The amount of tetanus toxoid removed from the array was determined by calculating the difference between initial tetanus toxoid levels and residual tetanus toxoid levels. The results are summarized in Table 2.

<tables num="1"><img file="JP4927751B2_D0001.tif" /></tables>

<u style="single">Example 8</u> The masking fluid used was FC-43 FLUORINERT® Electronic Liquid, a mixture of primary 12-carbon perfluoro compounds (3M Company (3M Co.), St. Paul, Minnesota). Coated arrays were prepared according to the procedure described in Example 1, except that there was and the amount of masking fluid applied was 15 μL. The tetanus toxoid content of the coated array, as measured by reverse phase HPLC, was 17.6 μg (st.dev. = 1.8 μg). The tetanus toxoid content on the tip of the microneedle was measured to be 2.7 μg (st.dev. = 0.2 μg).

<u style="single">Example 9</u> The microneedle array was placed on a flat surface with the needles pointing upwards. FC-43 FLUORINERT® Electronic Liquid was used as the masking fluid. Using a pipette, an aliquot (15 μL) of masking fluid was applied to the center of the array and spread across the array. The antigen coating formulation is the same part of the tetanus toxoid (Statens Serum). Institute) Lot 92-1, 888 Lf / mL) and prepared by mixing ethanol. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 16 μg. The antigen coating formulation and masking fluid were dried under ambient conditions for about 30 minutes to provide a dry antigen coating on the array. The total tetanus array array content measured by reverse phase HPLC was 23.6 μg (st.dev. = 0.1 μg). The content of the tetanus toxoid tip was measured as 21.7 μg (st.dev. = 1.2 μg).

<u style="single">Example 10</u> 825 mg polyvinylpyrrolidone (PVP) in 25 mL of water (Plasdone® K-29/32, Povidone USP, ISP Technologies, Wayne, NJ) Was added and mixed until the PVP was dissolved to prepare the PVP reservoir. 50 mg polysorbate 80 in 25 mL ethanol (Tween®-80, Sigma Chemical) Co.), Missouri, St. Louis (MO)) was added to prepare the reservoir. A diluted storage solution was prepared by adding 2 mL of polysorbate storage solution to 18 mL ethanol. A PVP priming solution was prepared by adding 1 mL of PVP storage to 9 mL of diluted polysorbate storage. A microneedle array was placed on a flat surface with the needles pointing upwards, and an aliquot of 30 μL of PVP priming solution was applied to the center of the array using a pipette and spread across the array. The PVP priming solution was dried under ambient conditions.

Tween®-80 (90 mg) was added to water (30 mL) to prepare a Tween®-80 reservoir at a concentration of 3 mg / mL. PVP (1.8 g) was added to water (20 mL) to prepare a PVP reservoir with a concentration of 90 mg / mL. Sucrose (1.8 g) was added to water (20 mL) to prepare a sucrose storage solution at a concentration of 90 mg / mL. Potassium citrate (1.8 g) was added to water (20 mL) to prepare a potassium citrate storage solution at a concentration of 90 mg / mL. Mixing tetanus toxoid (Statens Serum Institute Lot 92-1, 888 Lf / mL) with an aliquot of Tween®-80, PVP, sucrose and potassium citrate storage. Prepared an antigen coating formulation according to.

Using a pipette, an aliquot (15 μL) of masking fluid (FC-43 FLUORINERT® Electronic Liquid) was applied to the center of the array and spread across the array. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 10 μg. The nominal amount of Tween®-80 in the applied antigen coating formulation was 6 μg. The nominal amount of PVP, sucrose and potassium citrate in the applied antigen coating formulation was 100 μg. The antigen coating formulation and masking fluid were dried under ambient conditions for about 30 minutes to provide a dry antigen coating on the array. The total tetanus array array content measured by reverse phase HPLC was 11.9 μg (st.dev. = 0.5 μg). The content of the tetanus toxoid tip was measured as 5.0 μg (st.dev. = 1.2 μg).

<u style="single">Examples 11-14</u> Coated arrays were prepared according to the procedure described in Example 10, except that the nominal amounts of PVP, sucrose and potassium citrate were changed as shown in Table 2. The tetanus toxoid content of the coated array and the tetanus toxoid content on the tip of the microneedle, as measured by reverse phase HPLC, were measured. The results are shown in Table 2.

<tables num="2"><img file="JP4927751B2_D0002.tif" /></tables>

<u style="single">In vivo tetanus toxoid adhesion</u> Microneedle devices were prepared by adhering the antigen-coated arrays of Examples 10-14 to the adhesive backing. The array was applied to hairless guinea pigs using the applicators commonly described in US Patent Application No. 60 / 578,651. This document is incorporated herein by reference. The applicator piston mass was 5.08 g, and the device was applied at a speed of 8.07 m / s. The device was applied to the soft tissue of the abdomen and the muscles of the lumbar region below the ribs and just above the pelvis. Before applying the device, the application site was cleaned with 70% isopropyl alcohol and air dried for at least 30 seconds. The device (N = 5) was removed at a specific time and the content of tetanus toxoid remaining on the array was measured by HPLC. The results are summarized in Table 3.

<tables num="3"><img file="JP4927751B2_D0003.tif" /></tables>

<u style="single">Example 15</u> A polyvinyl alcohol priming solution was prepared as follows. Water (250 mg) of polyvinyl alcohol (80% hydrolyzed, typical Mw = 9,000-10,000, CAS 9002-89-5, Aldrich, St. Louis, Missouri) 25 mL) was added to prepare a polyvinyl alcohol storage solution. An aliquot (2 mL) of polyvinyl alcohol storage solution was added to ethanol (18 mL) to prepare a polyvinyl alcohol priming solution. The microneedle array was placed on a flat surface with the needles pointing upwards, and an aliquot of 30 μL of polyvinyl alcohol priming solution was applied to the center of the array using a pipette and spread across the array. The polyvinyl alcohol priming solution was dried under ambient conditions. Then, using a pipette, the masking fluid (FC-43 FLUORINERT® Electronic Liquid) Liquid)) aliquots (15 μL) were applied to the center of the array and spread across the array. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array. The antigen coating formulation was prepared according to the general procedure described in Example 10. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 10 μg. The nominal amount of Tween®-80 in the applied antigen coating formulation was 6 μg. The nominal amount of PVP, sucrose and potassium citrate in the applied antigen coating formulation was 100 μg. The antigen coating formulation and masking fluid were dried under ambient conditions for about 30 minutes to provide a dry antigen coating on the array. The total tetanus array array content measured by reverse phase HPLC was 10.4 μg (st.dev. = 0.7 μg). The content of the tetanus toxoid tip was measured as 9.3 μg (st.dev. = 0.4 μg).

<u style="single">Examples 16-23</u> Coated arrays were prepared according to the procedure described in Example 15, except that the nominal amounts of PVP, sucrose and potassium citrate were changed as shown in Table 4. The tetanus toxoid content of the coated array and the tetanus toxoid content on the tip of the microneedle, as measured by reverse phase HPLC, were measured. The results are shown in Table 4.

<tables num="4"><img file="JP4927751B2_D0004.tif" /></tables>

<u style="single">Example 24</u> Coated arrays were prepared according to the procedure described in Example 16. The total tetanus toxoid array content measured by reverse phase HPLC was 10.7 μg (st.dev. = 0.9 μg). The content of the tetanus toxoid tip was measured as 8.7 μg (st.dev. = 0.6 μg). The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 5.

<u style="single">Example 25</u> Coated arrays were prepared according to the procedure described in Example 17. The total tetanus toxoid array content measured by reverse phase HPLC was 11.4 μg (st.dev. = 0.3 μg). The content of the tetanus toxoid tip was measured as 8.6 μg (st.dev. = 0.5 μg). The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 5.

<u style="single">Example 26</u> Coated arrays were prepared according to the procedure described in Example 18. The total tetanus array array content measured by reverse phase HPLC was 10.8 μg (st.dev. = 0.3 μg). The content of the tetanus toxoid tip was measured as 6.8 μg (st.dev. = 0.9 μg). The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 5.

<u style="single">Example 27</u> Coated arrays were prepared according to the procedure described in Example 22. The total tetanus toxoid array content measured by reverse phase HPLC was 11.7 μg (st.dev. = 0.3 μg). The content of the tetanus toxoid tip was measured as 5.3 μg (st.dev. = 1.0 μg). The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 5.

<tables num="5"><img file="JP4927751B2_D0005.tif" /></tables>

<u style="single">Example 28</u> Microneedle arrays were prepared as described above and processed as follows. The array was plasma treated using the Plasma-Therm VII 7000 Series Plasma Processing System. Forming a diamond-like glass thin film by plasma adhesion by supplying a mixture of tetramethylsilane (150 standard cubic centimeters / minute, sccm) and oxygen (200 sccm) gas in uncompressed plasma with 2000 W RF power applied for 15 seconds. did. The array was then treated with oxygen plasma (400 sccm) at 300 W power for 60 seconds under a pressure of 150 mTorr to remove elements and covalent carbon from the surface atomic layer, resulting in a hydrophilic surface.

Using a pipette, Masking Fluid (FC-43 Fluorinert® Electronic Liquid) Liquid)) aliquots (15 μL) were applied to the center of the array and spread across the array. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array. The antigen coating formulation was prepared according to the general procedure described in Example 10. The nominal amount of tetanus toxoid in the applied antigen coating formulation was 10 μg. The nominal amount of Tween®-80 in the applied antigen coating formulation was 6 μg. The nominal amount of PVP, sucrose and potassium citrate in the applied antigen coating formulation was 100 μg. The antigen coating formulation and masking fluid were dried under ambient conditions for about 30 minutes to provide a dry antigen coating on the array. The total tetanus toxoid array content measured by reverse phase HPLC was 12.1 μg (st.dev. = 0.6 μg). The content of the tetanus toxoid tip was measured as 9.6 μg (st.dev. = 1.2 μg). The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 7.

<u style="single">Examples 29 ~ 32</u> Coated arrays were prepared according to the procedure described in Example 28, except that the nominal amounts of PVP, sucrose and potassium citrate were changed as shown in Table 6. The tetanus toxoid content of the coated array and the tetanus toxoid content on the tip of the microneedle, as measured by reverse phase HPLC, were measured. The results are shown in Table 6. The array was applied to hairless guinea pigs as described in the section "In vivo tetanus toxoid adhesion". The amount of tetanus toxoid remaining on the array after removal from the hairless guinea pig was measured by HPLC. The results are summarized in Table 7.

<tables num="6"><img file="JP4927751B2_D0006.tif" /></tables>

<tables num="7"><img file="JP4927751B2_D0007.tif" /></tables>

<u style="single">Example 33</u> A reservoir was prepared by mixing sucrose (1.053 g) and Tween®-80 (0.1053 g) in 100 mL of water. A volume (1.0 mL) of 0.02 micron fluorescent beads (Molecular Probes, Inc.), FluoSpheres carboxylate modified microspheres from Eugene, Oregon, red Fluorescent (580/605), 2.0% solid) was added to 19 mL of sucrose storage to prepare a coating formulation. The nominal concentration of sucrose is 1.0% (w / v), Tween®-80 is 0.1% (w / v), and fluorescent beads are 0.1% (w / v). It was.

Microneedle arrays were prepared as described above and processed as follows. The array was plasma treated using the Plasma-Therm VII 7000 Series Plasma Processing System. Diamond-like glass thin by plasma adhesion by supplying a mixture of tetramethylsilane (150 standard cubic centimeters / minute, sccm) and oxygen (500 sccm) gas forming plasma under 300 m Torr pressure with 500 W RF power applied for 2 minutes. A film was formed. The array was then treated with oxygen plasma (500 sccm) at 300 W power for 2 minutes under a pressure of 300 mTorr to remove elements and covalent carbon from the surface atomic layer, resulting in a hydrophilic surface. Equivalent surface treatment of a flat polycarbonate sheet yielded a material with a forward contact angle of 8 ° to deionized water at room temperature.

The treated microneedle array was placed on a flat surface with the needles pointing upwards. FC-43 FLUORINERT® Electronic Liquid was used as the masking fluid. Using a pipette, an aliquot (15 μL) of masking fluid was applied to the center of the array and spread across the array. Using a pipette, a 10 μL aliquot of the antigen coating formulation was applied to the center of the masking fluid on the array and dried. The coating formulation and masking fluid were dried under ambient conditions for at least 12 hours to provide a dry coating on the array. The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 100 percent of the microneedles were covered with a dry coating.

<u style="single">Example 34</u> The microneedle array was coated as described in Example 33, except that a diamond-like glass thin film was formed with a mixture of tetramethylsilane (50 sccm) and oxygen (500 sccm). Equivalent surface treatment of a flat polycarbonate sheet resulted in a material having a forward contact angle with respect to deionized water at room temperature. The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 24 percent of the microneedles were covered with a dry coating.

<u style="single">Example 35</u> The microneedle array was coated as described in Example 33, except that a diamond-like glass thin film was formed with a mixture of tetramethylsilane (150 sccm) and oxygen (500 sccm). Equivalent surface treatment of a flat polycarbonate sheet yielded a material with a forward contact angle of 40 ° to deionized water at room temperature. The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 20 percent of the microneedles were covered with a dry coating.

<u style="single">Example 36</u> Microneedle arrays were coated as described in Example 33, except that the coating formulation was prepared at a nominal sucrose concentration of 25% (w / v). The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 61 percent of the microneedles were covered with a dry coating.

<u style="single">Example 37</u> Microneedle arrays were coated as described in Example 34, except that the coating formulation was prepared at a nominal sucrose concentration of 25% (w / v). The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 27 percent of the microneedles were covered with a dry coating.

<u style="single">Example 38</u> Microneedle arrays were coated as described in Example 35, except that the coating formulation was prepared at a nominal sucrose concentration of 25% (w / v). The array was observed under a microscope and the percentage of microneedles coated with a dry coating was determined. Approximately 19 percent of the microneedles were covered with a dry coating.

The present invention is described by reference to some of those embodiments. The above detailed descriptions and examples are provided for clarity understanding only, from which unnecessary limitations are not understood. It will be apparent to those skilled in the art that the described embodiments can be modified without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the exact details of the composition and structure described herein, but rather to the claims.

<figref num="1">It is a schematic cross-sectional view of the microneedle array before coating.</figref><figref num="2">FIG. 5 is a schematic cross-sectional view of an array in which masking fluid is applied to a substrate.</figref><figref num="3A">It is a schematic cross-sectional view of the array to which the coating fluid was applied.</figref><figref num="3B">It is a schematic cross-sectional view of the array which evaporated a part of the coating fluid.</figref><figref num="3C">FIG. 5 is a schematic cross-sectional view of an array in which a coating fluid is evaporated so that a dry coating remains.</figref><figref num="3D">It is a schematic cross-sectional view of the array which evaporated a part of the masking fluid.</figref><figref num="3E">FIG. 5 is a schematic cross-sectional view of an array in which the masking fluid is evaporated so that an array having a dry coating remains on the needle tip.</figref><figref num="4">FIG. 6 is a schematic cross-sectional view of another embodiment of a microneedle array in which a masking fluid is applied to a substrate.</figref><figref num="5">It is a schematic cross-sectional view of the microneedle array to which a masking film was applied.</figref><figref num="6A">It is a schematic cross-sectional view of the microneedle array of FIG. 5 to which the coating fluid was applied.</figref><figref num="6B">It is a schematic plan view of the microneedle array of FIG. 5 to which the coating fluid is applied.</figref><figref num="6C">FIG. 5 is a schematic cross-sectional view of an array in which the coating is evaporated so that the dry coating remains.</figref><figref num="7">It is a schematic perspective view of a patch microneedle device.</figref>