Vaporizer for inhalation and method for extraction of active ingredients from a crude natural product or other matrix

Description of equivalent WO 9911311 A1

VAPORIZER FOR INHALATION AND METHOD FOR EXTRACTION OF ACTIVE INGREDIENTS FROM A CRUDE NATURAL PRODUCT

OR OTHER MATRIX

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation- in-part of Application Serial No. 08/919,317, filed August 28, 1997, the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a vaporizer for inhalation and a method for extraction of active ingredients from a crude natural product or other matrix, by means of an ascending airstream heated to the temperature appropriate to volatilize the molecules .

The use of plants as medicinal agents has a long and successful history. The majority of medicines used today are either derived directly from plants or synthesized as variations on natural molecules. However, modern medical practice has, for the most part, abandoned the use of whole plant products because of objections concerning variability in concentration of active ingredients, and unpredictable rates of active drug release from orally ingested crude drugs. Even teas made from medicinal plants cannot fully overcome the latter objection, as the dose provided depends on compound solubility and the conditions of extraction. In addition, accurate self -titration of this dose cannot be expected to overcome either objection, considering the excessive time-lag between oral ingestion and the onset of action. The best resolution of these problems is through pulmonary ingestion of vaporized compounds, if they are sufficiently volatile. This provides a more immediate means of relief and a more accurate method for dose self-titration, as well as allowing a means for applying compounds to the pulmonary tract itself, as is necessary with diseases such as bronchial asthma, etc. Pulmonary ingestion of drugs also circumvents the "first -pass effect" by which oral drugs are transferred from the intestines and then partially or entirely metabolized by the liver, before entering the blood stream.

Unfortunately, the only technique available to accomplish pulmonary application of crude natural drugs has been via the method of smoking. This is objectionable from the medical perspective because pyrolysis products are irritating and long-term ingestion of smoke has been implicated in the etiology of various pulmonary disease states (e.g., emphysema, cancer, etc . ) .

Other objections to inhalers such as U.S. Pat. No. 87,603 (Tichenot) which continuously heats or pyrolizes a substance on a grating, and U.S. Pat. No. 1,858,580 (Collins) which steam heats a carrying agent permeated with a medicated substance, involve the lack of ability to either maximize the extraction exposure of the specimen particles, or to promote a uniform extraction of the aggregate charge through its periodic mixing. Additionally, prevention of large particle inhalation which may prove irritating to the pulmonary system of the user, and providing a demand- only flow of heated gas upon each inhalation, which spares wasteful loss of active ingredient during periods of device disuse, is not achieved.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a vaporizer and a method by which a hot gas stream vaporizes and uniformly extracts the active ingredients of a crude natural product or other specimen without pyrolysis, thereby avoiding the potentially detrimental effects of smoking. A further object of the present invention is to spare the wasteful loss of active ingredients extracted by the vaporizer due to a continuous gas flow instead of a demand-only gas flow, and also to prevent the inhalation of large particles by the user due to a lack of a filtering mechanism.

A still further object of the present invention is to prevent clogging of the vaporizer apparatus due to evaporated compounds condensing on the permeable support structure of the vaporizer apparatus.

Yet another object of the present invention is to initiate a high speed of air flow through the vaporizer, such that lofting of the crude natural product is more easily achieved, in order to maximize the extraction of the active ingredients, without excessive inhalation force.

The present invention extracts volatile active ingredients from a crude natural product, as well as other volatile substances (e.g., essential oils) impregnated into an inert matrix (e.g., paper), by means of a moving airstream heated to the temperature appropriate to volatilize the molecules of the product or substance. Transfer of these agents or ingredients as a water-free aerosol is simultaneously accomplished by this same airstream. In addition, the means of introducing the heated gas into the pulverized crude drug from below provides for the solid particulates to be suspended in the airstream, completely exposing them to the extractive gases, as well as causing a mixing of the aggregate charge upon each inhalation. In cases where prevention of labile active compound denaturation (e.g., oxidation) is required, the substitution of a stream of hot inert gas (e.g., helium, argon) for the stream of hot air can be implemented. The use of helium carries the additional advantage of raising the voice pitch of the inhaler, reminding the user that air has not been inhaled.

Upon each inhalation, the heated gas is introduced from below and ascends through, in most embodiments, a permeable support structure (e.g., fritted glass disk, etc.), subsequently causing specimen particles to be suspended within the confines of the isolation chamber. This allows a maximized gas extraction exposure for each suspended particle and promotes a uniform extraction of the aggregate charge through its periodic mixing. In addition, this method ensures that the support structure is kept clean and unclogged, since evaporated compounds are constantly swept away from its upper surface. A filter provided downstream from the permeable support structure prevents large particles from being inhaled by the user.

During device disuse in one embodiment, the heated airstream flows through a side-arm of the vaporizer apparatus, preventing wasteful loss of active ingredients. In another embodiment, the side arm can also be used to divert mixed purge gases from the specimen, when the specimen is required to be under the flow of inert gas during its extraction.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, wherein:

FIGURE 1 shows an exploded view of the completed assembly of the vaporizer apparatus according to a first embodiment of the invention.

FIGURE 2 shows the completed assembly of the vaporizer apparatus according to a first embodiment of the invention. FIGURE 3A shows the isolation chamber of the vaporizer apparatus with the specimen particles in their normal state.

FIGURE 3B shows the isolation chamber of the vaporizer apparatus with the specimen particles suspended by the ascending heated gas low through the isolation chamber.

FIGURE 4 shows the disk filter screen retention assembly of the vaporizer apparatus and a metal clip removal tool .

FIGURE 5 shows the hollow cylindrical filter screen of the invention.

FIGURE 6 shows the assembly of the hollow cylindrical filter screen of the vaporizer apparatus and a metal clip removal tool.

FIGURES 7A and 7B show the hot air gun with cradle and rod assembly of the vaporizer apparatus.

FIGURES 8, 9, and 10, show a more detailed view of the cradle and rod assembly of the vaporizer apparatus .

FIGURE 11 shows the completed assembly of the vaporizer apparatus according to a second embodiment of the invention.

FIGURE 12 shows a conical fritted disk and the isolation chamber of the vaporizer apparatus according to a third embodiment of the invention.

FIGURE 13 shows a bottom view of the integral baffle in the tubing of the vaporizer apparatus according to a third embodiment of the invention. FIGURE 14 shows a cap in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention.

FIGURE 15 shows a top view of the cap in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention.

FIGURE 16 shows the specimen particles lofted in the isolation chamber of the vaporizer apparatus according to a fourth embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A completed assembly of the first embodiment of the vaporizer apparatus 1 of the present invention is shown in Figure 2, with an exploded view shown in Figure 1. The vaporizer apparatus 1 is mounted on a source of hot air 2 (e.g., Bosch Model 1943 or Model

PHG 630-2 LCE hot air gun) , and includes an optional internal diverter 3, which acts as a baffle-cum-brace within a glass tubing 4 which connects the source of hot air 2 to an isolation chamber 5 containing a permeable support structure 6 (e.g., fritted glass disk), and to a side-arm 7. The optional internal diverter 3, which increases efficiency if used, is fitted on the source of hot air 2 in order to secure the vaporizer apparatus 1 to the hot air source 2. When the user inhales, the partial vacuum created allows hot air to stream past the curved section of the upper portion of the diverter 3 through the permeable support structure 6. Between inhalations, the diverter 3 acts as a baffle, encouraging hot air to stream out through the side-arm 7 rather than flowing upward through the permeable support structure 6.

The isolation chamber 5 holds the specimen particles 8 (see Figures 3A and 3B) on the surface 9 of the permeable support structure 6. The permeable support structure 6 is fixed to the walls of the glass tubing 4. A disk filter screen 10 is disposed above, or downstream of the isolation chamber 5, and a tubing 11 (see Figure 2) leads from the disk filter screen 10 to a mouthpiece 12 or a mask (not shown) through which the user inhales. The tubing 11 may be corrugated which allows flexing of the tube without kinking (not shown) .

The side arm 7 (see Figures 1 and 2) provides means to duct the heated air stream away from the permeable support structure 6 when the vaporizer apparatus 1 is not in use (e.g., when the user is resting between inhalations) . The side arm 7 can be equipped with a valve 24 to manually re-route the entire heated airstream through the permeable support structure 6 for ancillary purposes such as device cleaning, or as a room vaporizer upon removal of the tubing 11. As an example, the valve 24 could be provided with either a silicone stopper or, alternatively, could be manually clamped by a hemostat, pmchcock or other similar compression device (not shown) . The wall thickness of this short piece of silicone tubing also provides the user insulation from the hot glass side arm 7 underneath

Figure 4 shows the disk filter screen retention assembly. In order to assemble the disk filter screen retention assembly, the disk filter screen 10, which is made of a finely meshed material (e.g., stainless steel) , is first seated m an outer filter retention ring 13. Then, the arms 20 of a metal clip tool 21 are inserted into holes 19 which are located m the inner peripheral surface of inner filter retention ring 14, and disposed directly across from one another. The inner filter retention ring 14 is then threaded into the outer filter retention ring 13 by turning the tool 21 to tighten the inner filter retention ring 14 within the outer filter retention ring 13 and keep the disk filter screen 10 stable between the two structures 13, 14. Next, the outer filter retention ring 13 is inserted into an interface ring 15 made of a heat- resistant synthetic material (e.g., fluorocarbon) . The interface ring 15 is provided in the lower portion of a glass headpiece 16, which fits onto the upper portion of the glass tubing 4. The interface ring 15 is laterally compressed into an ovoid shape and is inserted through the bottom of the glass headpiece 16. Interface ring 15 includes an upper lip 18d, a lower lip 18c, a groove 18a, and gap 18b within the lower lip 18c of the groove 18a, all within its inner periphery, which are operative to provide a locking fit to the outer filter retention ring 13.

Namely, pins 17a, 17b, which are disposed on the outer peripheral surface of the outer filter retention ring 13, are aligned with gap 18b of groove 18a of the interface ring 15, and are inserted through the gap

18b into the groove 18a. The subassembly of the outer filter retention ring 13, inner filter retention ring 14 and disk filter screen 10, is then turned using the tool 21, to provide a locking fit of the subassembly within the interface ring 15 (bayonet-type coupling) .

To remove the disk filter screen retention assembly, the steps above are conducted in reverse order.

A hollow cylindrical filter screen 22, shown in Figure 5, can be used as an alternative to the disk filter screen 10, in order to increase the surface area of the filtering means and provide additional height for specimen particles 8 to ascend from their origin on the surface 9 of the permeable support structure 6. The cylindrical filter screen 22 is made of a meshed material (e.g., stainless steel), and is assembled within the inner filter retention ring 14 and outer filter retention ring 13 as shown in Figure 6 (like elements being denoted by like reference numerals) , in the same manner as the disk filter screen 10, discussed above. The closed top portion 23 of the hollow cylindrical filter screen 22 can have any shape, including a domed, conical or flat surface.

The vaporizer apparatus 1 (see Figures 7A-10) is supported by a support cradle 25, which can be semi- permanently attached by screws or the like, mounted in threaded holes 30 and fixed to the handle 26 of a hot air gun 2. The support cradle 25 accommodates an easily mountable/demountable rod 27 via a rod receiving channel 28 disposed in the lower portion of the support cradle 25. A receiving groove 29 fixes rod 27 via a spring-ball screw or the like, mounted in threaded hole 31. Accordingly, by using the support cradle 25 and rod 27 apparatus, the entire vaporizer apparatus 1 can be laterally stabilized. Removal of the rod 27 allows flat storage of the vaporizing apparatus 1 or alternative uses of the hot air gun 2 itself in a variety of unrelated hand-held applications .

The operation of the present invention, with respect to the first embodiment shown in Figures 1 and 2, begins when the glass headpiece 16 of the isolation chamber 5 is removed and a small charge of specimen particles 8 (crude natural product or inert particulate matrix impregnated with the desired compounds) is placed in the isolation chamber 5, and the glass headpiece 16 replaced to close the isolation chamber 5.

The source of hot air (e.g., hot air gun) 2 is then turned on to bring the air- stream to the proper predetermined temperature. The source of hot air 2 provides a heated gas flow, which the internal diverter 3, acting as a baffle, routes through the side-arm 7. Inhalation provides the drop in pressure necessary to re-route a portion of the heated gas stream past the internal diverter 3 and through the permeable support structure 6. The proper predetermined working temperature of the air stream through the vaporizer apparatus 1 will vary according to the nature of the materials being volatilized, from approximately 50 to 250 degrees Celsius, but it is generally in the 100 to 200 degree Celsius range. Inhalation draws a portion of the diverted hot airstream upwards through the permeable support structure (e.g., fritted glass disk) 6, to enter the isolation chamber 5 under the specimen charge. The aggregate charge is suspended as a cloud of particles 8, completely exposing each component particle to the extractive stream of hot air (see Figure 3B) . Accordingly, volatile components of the specimen are vaporized from the suspended specimen particles 8 by the hot air and this vapor is drawn into the pulmonary tract by inhaling, via the tubing 11 through the mouthpiece 12 or a mask (not shown) .

Cessation of inhalation stops the upward flow of heated air through the chamber and allows gravity to collapse the cloud of suspended particles 8 back into its original state as a layer on the surface 9 of the permeable support structure 6 (see Figures 3A and 3B) .

Backflow of outside unheated air through the side arm 7 during inhalation is avoided due to an overpressure maintained by the source of hot air 2 that is in excess of the pressure removed by the inhalation.

Inhalation of large particles 8 is prevented by the filter screen 10 disposed above the isolation chamber 5. When not in active use, the system functions to allow the air and, therefore, the entire vaporizer apparatus 1, to maintain its optimal temperature, while avoiding a constant flow of heated gas through the specimen particles 8 whose active ingredients are to be extracted. This bypass effect is interrupted only on demand by inhalation, thereby sparing wasteful loss of active ingredients during periods of device disuse . The disk filter screen 10 is self-cleaned at the end of each inhalation, of most specimen particles 8 by this same gravitational action. However, a sharp momentary exhalation into the tubing 11 also helps to force most residual specimen particles 8 away from the disk filter screen 10.

The exhausted charge of specimen particles 8 is emptied from the vaporizer apparatus 1 by turning off the heat source air flow, removing the glass headpiece 16 from the top of the isolation chamber 5 and then either scooping or vacuuming out the contents, or by lifting the cooled glass tubing 4 from the source of hot air 2 and inverting the vaporizer apparatus 1 to empty the contents of the isolation chamber 4. The specimen particles 8 may also be removed by simply lifting the glass headpiece 16 while sharply inhaling, thereby ensuring particles are adherent on the disk filter screen 10.

In a second embodiment of the present invention as shown in Figure 11, a heated inert gas (i.e., helium, argon) is used instead of heated air. The heated inert gas is used to evaporate volatile compounds from their matrix in order to prevent their decomposition due to exposure to atmospheric gases (e.g., oxygen). Again, like elements are denoted by like reference numerals.

The second embodiment of the vaporizer apparatus 1 (see Figure 11) includes a high pressure tank 32 of inert gas equipped with a demand-type SCUBA regulator 33 equipped with a refill port 34. A hose or tubing 35 from this regulator 33 is routed to a heat-exchange device 36. The heat exchange device 36 includes a heating band 37 or other resistance heating device made of metal, silicone, or other material, that generates heat from electrical input. A thermostatic control 38 regulates the electrical input to the heating band 37 so that the chamber or vessel 39 contained within the heat exchange device 36 is limited to a desired predetermined range of temperatures. A thermostatic sensor 40 acts as a heat detection device that determines the temperature of the heated vessel 39, and transmits the data to the thermostatic control 38. A thermometer 41 measures the internal temperature status of the contents of the vessel 39, and provides visual feedback to the user. The heating band 37 heats the heat exchange spheres 42, which are made of metal, glass, ceramic, or other suitable material . The heat exchange spheres 42 provide a large surface area upon which the percolating gases can be instantaneously heated.

The insulation 43 surrounding the vessel 39 of the heat exchange device 36 is made of glass, ceramic, or other suitable material , and traps the heat generated by the heating band 37 to ensure temperature stability for the heat exchange spheres 42. The insulation 43 is normally contained within an outer protective casing 44 made of metal or other material .

A vertical pipe 45 disposed within the vessel 39 amongst the heat exchange spheres 42, and which has an upper portion which projects upwardly out of the heat exchange device 36, has a glass tubing 46 fitted over its upper portion. The glass tubing 46 contains an isolation chamber 5, the lower portion of which seats a permeable support structure 6. A glass headpiece 16 is fitted into the isolation chamber 5.

As with the first embodiment, the isolation chamber 5 holds the specimen particles 8 (see Figures

3A and 3B) on the surface 9 of the permeable support structure 6. The permeable support structure 6 is fixed to the walls of the glass tubing 46. A filter screen 10 is disposed above, or downstream of the isolation chamber 5, and a tubing 11 leads from the filter screen 10 to a mouthpiece 12 or a mask (not shown) through which the user inhales. As with the first embodiment, the tubing 11 may be corrugated (not shown) which allows flexing of the tube without kinking. A hollow cylindrical filter screen 22 can be used instead of the disk filter screen 10.

In initial operation of the invention with respect to the second embodiment, the demand-type pressure regulator 33 of the tank 32 of inert gas, is first opened via its purge valve 47 so that the gas flows through the tubing 35 into the heat exchange vessel 39 and then out via tube opening 7, purging residual air in the vaporizer apparatus. Tube 7 is then blocked by using a stopper or suitably clamping the attached silicone tubing 24 (not shown) (see Figure 2) .

Once in the heat exchange device 36, the inert gas is heated by heat exchange spheres 42 in the heat exchange vessel 39 to the proper predetermined temperature. After charging the isolation chamber 5 with a specimen to be extracted (e.g., crude natural product or inert particulate matrix impregnated with the desired compounds) , inhalation draws additional inert gas from the pressure tank 32 via the heat exchange device 36. The heated inert gas proceeds upwards through the vertical pipe 45 and through the permeable support structure 6, entering the isolation chamber 5 which contains the charge of specimen particles 8. The remaining structure and steps in the procedure are the same as that described above with the first embodiment. In the second embodiment of the invention, side- arm 7 venting of gas is not absolutely necessary. However, if the isolation chamber 5 is to be charged with specimen particles 8 before the purging of residual air from the heat exchange vessel 39, a manually valved side-arm 7 venting feature is useful to prevent heated mixed gases from sweeping over the specimen particles 8 until the system is free of air. Removal of the exhausted charge of specimen particles 8 is initiated by removing the glass headpiece 16 from the top of the isolation chamber 5. The cooled glass tubing 46 that houses the permeable support structure 6 can then be removed from the glass tubing 45 and inverted to empty its contents resting on the surface 9. All the other removal techniques discussed above with respect to the first embodiment, can also be used. In a third embodiment of the present invention, the baffle 103 (see Figures 12 and 13) of the vaporizer apparatus 101 is formed integrally with the vertical tubing 104, the latter of which can be made from glass, plastic material (e.g., polysulfone, Torlon^®, PEEK, Liquid Crystal, etc.) or other suitable material (see Figure 12) . Radial air-cooling fins, to prevent finger burns, may optionally be provided on the outside of side-arm 102 and tubing 104 of the vaporizer apparatus 101. The side-arm 102 has a bevel

(e.g., 70°) for more diffuse air dispersal.

A Venturi restriction 105 is provided in the upper portion of tubing 104, which has an optional cylindrical flotation chamber 106 provided above the Venturi restriction (see Figure 12) . A permeable support structure made from fritted glass or other appropriate porous material, which is a conical disk

107, is provided immediately below the Venturi restriction 105 and above baffle 103. The tubing 104 has a waisted portion 108 below the Venturi restriction 105, which parallels the shape of the conical fritted disk 107. A headpiece 116 is provided above the tubing 104 at the point where tubing 104 regains its full diameter above the Venturi restriction 105, and includes a cylindrical filter screen 110, made of a meshed material (e.g., stainless steel) , similar to that of the filter screen 22 or 10 of the first embodiment of the invention.

In operation of the third embodiment of the present invention, the specimen particles 118 (crude natural product or inert particulate matrix impregnated with the desired compounds) are placed in the top of the tubing 104 and settle on the surface of the conical fritted disk 106. As with the first embodiment, the source of hot air (e.g., hot air gun) (not shown in Figure 12) is then turned on to bring the air-stream to the proper predetermined temperature, to provide a heated gas flow. Inhalation provides the drop in pressure needed to re-route a portion of the heated gas stream past the baffle 103 and through the conical permeable disk 107 to loft the specimen particles 118. However, due to the shape of the conical fritted disk 107, more surface area is provided which makes it easier to draw air through for the user. Further, the narrow gap between the conical fritted disk 107 and the parallel wall 108 of the waisted section of tubing 104, maintains a high speed air flow induced by the Venturi restriction 105, to make it easier for the user to loft the material while inhaling more normally. As described in the first embodiment, upon inhalation, the aggregate charge is suspended as a cloud of particles, completely exposing each component particle to the extractive stream of hot air, and volatile components are vaporized. The vapor is drawn through the headpiece and via tubing, to the user. The filter screen 110 prevents the inhalation of large particles .

The fourth embodiment of the present invention is similar to the third embodiment of the invention, with the exception that the hourglass -like Venturi restriction 105 m the cylindrical tubing 104 m the third embodiment, is replaced with that of spherical tubing 201 containing a cap 202 atop cylindrical neck or support tube 203 (see Figure 14) . The spherical tubing 201 is made from glass, plastic or other suitable material as described above m the third embodiment. The cap 202 is a conical disk made of glass, plastic or other suitable material as described m the third embodiment, which is welded or molded onto tube 203 m the base of the tubing 201. The cap 202 has support struts 204 (see Figure 15) at the base which is used for attachment (welding or molding) onto the cylindrical tube 203. Other than the support struts 204, the cap 202 is open at its base, and forms an internal Venturi that accelerates airflow m a manner similar to that of the Venturi restriction 105 of tube 104 of the third embodiment. This arrangement also serves to momentarily divert the flow of air in a reversed direction. In the fourth embodiment, the air diverter baffle 206 also deflects particles, which may fall down cylindrical tube 203, away from the opening of the hot air source (not shown) .

In operation of the fourth embodiment, the specimen particles 207 are placed in the top of the tubing 201, and settle around the cylindrical support 203. Due to the small orifice provided by the gap between the vertical cylindrical support 203, and the cap 202, when the user inhales, there is a localized increase in airspeed through this gap which then flows between the cylindrical support 203 and cap 202 (see Figure 16) . The specimen particles 207 are then lofted by the high speed airflow more easily, and the user can inhale more normally.

It is contemplated that numerous modifications may be made to the apparatus and procedure of the invention without departing from the spirit and scope of the invention as defined in the following claims.