Patent Application
20210378951
The present invention relates to a microneedle array and a method of producing the same. The present invention particularly relates to a microneedle array containing influenza vaccine and a method of producing the same.
In recent years, a dissolution type microneedle array in which a base material formed of a substance that is dissolvable in vivo contains a drug has been developed. Since needles of a microneedle array are thin and short, stimulation to nerves is small. Therefore, a microneedle array is also referred to as a “painless injection”.
JP2009-522288A describes a method of producing a transdermal delivery device, including a step (i) of providing a fine projection member having a plurality of fine projections; a step (ii) of providing a biocompatible coating dosage form containing a bioactive drug; a step (iii) of coating the fine projection member with the biocompatible coating dosage form to form a transdermal delivery device; and a step (iv) of packaging the transdermal delivery device under an inert atmosphere condition and/or in a partial vacuum in which the transdermal delivery device has been dried. JP2009-522288A describes that meglumine may be added as a counterion of the biological agent. The microneedle array described in JP2009-522288A is not a self-dissolving microneedle array in which a drug is administered into the body by dissolution of needle portions. In addition, WO08/132363A describes a drug obtained by stabilizing a protein, which contains meglumine.
In the related art, administration of influenza vaccine is performed by subcutaneous and intramuscular injections. However, fear of injection needles, pain during the injection, and mental stress are problems. In order to solve the problems, administration carried out using a microneedle array has been suggested as a method that does not cause pain. In particular, a microneedle array including a vaccine is expected to improve the effectiveness, and an influenza vaccine-including microneedle array is expected to be available.
Since a microneedle array is a fine preparation, the microneedle array is required to have a small volume for containing a drug and contain a drug at a higher concentration than that of an injection. Therefore, the distance between the drugs is decreased, and thus there is a possibility that the aggregation or reaction is likely to occur and the stability of the drug may be impaired. A result that even in a case of the microneedle array including influenza vaccine which has been examined by the present inventors, the stability of the influenza vaccine is impaired as compared with the injection is obtained, and thus there is a demand for improving the stability of the influenza vaccine.
Further, in a case where there is a part where the drug included in a microneedle array is not administered in a living body, a large amount of the drug is wastefully consumed. Therefore, the drug needs to be concentrated on the tip of a needle in the microneedle array.
An object of the present invention is to provide a microneedle array in which the stability of influenza vaccine is satisfactory and the utilization efficiency of the influenza vaccine is high, and a method of producing the same.
As a result of intensive examination conducted by the present inventors in order to achieve the above-described object, it was found that in a microneedle array containing influenza vaccine, the stability of the influenza vaccine with time is improved and tip filling performance of the influenza vaccine is also improved by adding meglumine or a salt thereof to a needle portion containing influenza vaccine. The present invention has been completed based on these findings.
That is, according to the present invention, the following inventions are provided.
In the influenza vaccine-including microneedle array according to the aspect of the present invention, the stability of the influenza vaccine is satisfactory, and the utilization efficiency of the influenza vaccine is high.
Hereinafter, embodiments of the present invention will be described in detail.
In the present specification, the expression “containing a drug” means that a drug having an amount enough to exhibit drug efficacy is contained in a case of puncturing the body surface. The expression “not containing a drug” means that a drug having an amount enough to exhibit drug efficacy is not contained, and a range of the amount of the drug covers from a case where the drug is not contained at all to a case where the amount thereof is not enough to exhibit the drug efficacy.
In a microneedle array according to the embodiment of the present invention, a needle portion contains meglumine, and thus the stability of influenza vaccine can be improved and the influenza vaccine can be localized at the tip of the needle portion. The effect that the stability of the influenza vaccine can be improved and the influenza vaccine can be localized at the tip of the needle portion by allowing a needle portion to contain meglumine cannot be expected in the related art. Further, the microneedle array according to the embodiment of the present invention is not intended to use the coating type described in JP2009-522288A. That is, the microneedle array according to the embodiment of the present invention is a self-dissolving microneedle array in which a drug is administered into the body by dissolution of the needle portion.
[Configuration of Microneedle Array]
The microneedle array according to the embodiment of the present invention is a self-dissolving microneedle array including a sheet portion, and a plurality of needle portions which are present on an upper surface of the sheet portion, in which each needle portion contains influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof, and the influenza vaccine which is a drug is administered into a body by dissolution of the needle portions.
In the present invention, plural means one or more.
The microneedle array according to the embodiment of the present invention includes at least a sheet portion and needle portions and a drug is carried by the needle portions in order to efficiently administer the drug into the skin.
The microneedle array according to the embodiment of the present invention is a device in which a plurality of needle portions are arranged in an array on the upper surface side of the sheet portion. It is preferable that the needle portions are arranged on the upper surface side of the sheet portion. The needle portions may be arranged directly on the upper surface of the sheet portion or may be arranged on the upper surfaces of frustum portions arranged on the upper surface of the sheet portion.
The sheet portion is a foundation for supporting the needle portions and has a planar shape as the shape of a sheet portion 116 illustrated in
The area of the sheet portion is not particularly limited, but is preferably in a range of 0.005 to 1000 mm2, more preferably in a range of 0.1 to 800 mm2, and still more preferably in a range of 1 to 800 mm2.
The thickness of the sheet portion is a distance between the surface in contact with frustum portions or needle portions and the surface on the opposite side. The thickness of the sheet portion is preferably 1 μm or greater and 2000 μm or less, more preferably 3 μm or greater and 1500 μm or less, and still more preferably 5 μm or greater and 1000 μm or less.
It is preferable that the sheet portion contains a water-soluble polymer. The sheet portion may be formed of a water-soluble polymer or may contain other additives (for example, disaccharides). Further, it is preferable that the sheet portion does not contain a drug.
The water-soluble polymer contained in the sheet portion is not particularly limited, and examples thereof include polysaccharides (such as hyaluronic acid, sodium hyaluronate, pullulan, dextran, dextrin, sodium chondroitin sulfate, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl starch, hydroxypropyl methyl cellulose, polyvinylpyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and arabic rubber) and proteins (such as gelatin). The above-described components may be used alone or in the form of a mixture of two or more kinds thereof. Among these, polysaccharides are preferable, hydroxyethyl starch, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, pullulan, dextran, sodium chondroitin sulfate, sodium hyaluronate, carboxymethyl cellulose, polyvinylpyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and polyvinyl alcohol are more preferable, and chondroitin sulfate and dextran are particularly preferable.
Disaccharides may be added to the sheet portion and examples of the disaccharides include sucrose, lactulose, lactose, maltose, trehalose, and cellobiose. Among these, sucrose, maltose, and trehalose are particularly preferable.
The microneedle array is formed of a plurality of needle portions arranged in an array on the upper surface side of the sheet portion. The needle portions have a projected structure with a tip, and the shape thereof is not limited to a needle shape having a sharp tip and may be a shape with a blunt tip.
Examples of the shape of a needle portion include a conical shape, a polygonal pyramid shape (square pyramid shape or the like), and a spindle shape. For example, a needle portion may have a shape of the needle portion 112 illustrated in any of
In a case where the microneedle array according to the embodiment of the present invention is applied to the skin, it is preferable that the needle portions are inserted into the skin and the upper surface or a part of the sheet portion is brought into contact with the skin.
The height (length) of a needle portion indicates the length of a perpendicular line drawn from the tip of the needle portion to the frustum portion or the sheet portion (in a case where a frustum portion is not present). The height (length) of a needle portion is not particularly limited, but is preferably 50 μm or greater and 3000 μm or less, more preferably 100 μm or greater and 1500 μm or less, and still more preferably 100 μm or greater and 1000 μm or less. It is preferable that the length of a needle portion is 50 μm or longer because a drug can be percutaneously administered. Further, it is preferable that the length of a needle portion is 3000 μm or less because occurrence of pain resulting from the contact of needle portions with the nerve is prevented and bleeding can be avoided.
The interface between a frustum portion (or a needle portion in a case where a frustum portion is not present) and the sheet portion is referred to as a base portion. The distance between the farthest points on a base portion of one needle portion is preferably 50 μm or greater and 2000 μm or less, more preferably 100 μm or greater and 1500 μm or less, and still more preferably 100 μm or greater and 1000 μm or less.
The number of needle portions to be arranged in one microneedle array is preferably in a range of 1 to 2000, more preferably in a range of 3 to 1000, and still more preferably in a range of 5 to 500. In a case where one microneedle array includes two needle portions, the interval between needle portions indicates the distance between feet of each perpendicular line drawn from the tip of a needle portion to a frustum portion or the sheet portion (in the case where a frustum portion is not present). In a case where one microneedle array includes three or more needle portions, the interval between needle portions to be arranged indicates an average value obtained by acquiring the distance between a foot of a perpendicular line drawn from the tip of a needle portion to a frustum portion or the sheet portion (in the case where a frustum portion is not present) and a foot of a perpendicular line drawn from the tip of a needle portion nearest to the needle portion to a frustum portion or the sheet portion and averaging the values obtained from all needle portions. The interval between needle portions is preferably 0.1 mm or greater and 10 mm or less, more preferably 0.2 mm or greater and 5 mm or less, and still more preferably 0.3 mm or greater and 3 mm or less.
The needle portions contain influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof. It is preferable that the water-soluble polymer is a biosoluble substance such that a human body is not damaged even in a case where needle portions remain in the skin.
The water-soluble polymer contained in the needle portions is not particularly limited, and examples thereof include polysaccharides (such as hyaluronic acid, sodium hyaluronate, pullulan, dextran, dextrin, sodium chondroitin sulfate, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl starch, hydroxypropyl methyl cellulose, polyvinylpyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and arabic rubber) and proteins (such as gelatin). The above-described components may be used alone or in the form of a mixture of two or more kinds thereof. Among these, polysaccharides are preferable, hydroxyethyl starch, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, pullulan, dextran, sodium chondroitin sulfate, sodium hyaluronate, carboxymethyl cellulose, polyvinylpyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and polyvinyl alcohol are more preferable, and hydroxyethyl starch and dextran are particularly preferable. Further, typically polysaccharides having no electric charge are more preferred because aggregation is unlikely to occur in a case where such polysaccharides are mixed with a drug. The water-soluble polymer contained in the needle portions may be the same as or different from the water-soluble polymer contained in the sheet portion.
The content of the water-soluble polymer contained in the needle portions is preferably 10% by mass or greater and 99% by mass or less, more preferably 10% by mass or greater and 70% by mass or less, and still more preferably 20% by mass or greater and 50% by mass or less with respect to the solid content of the needle portions.
The needle portions contain influenza vaccine as a drug.
The influenza vaccine may contain only one or two or more kinds of virus antigens. In a case where a particular influenza virus is prevalent and a particular strain of vaccine is rapidly produced and supplied, it is preferable that the vaccine contains only one virus antigen. In a case where immunity against a wide range of virus strains is imparted by vaccine administration, it is preferable that the vaccine contains two or more kinds of virus antigens. It is preferable that the influenza vaccine contains an influenza A virus antigen, an influenza B virus antigen, or mixtures thereof. It is more preferable that the influenza vaccine contains an influenza A H1N1 virus antigen, an influenza A H3N2 virus antigen, an influenza B virus antigen, or a mixture thereof. In a case where the influenza vaccine contains two or more kinds of virus antigens, the amount of antigens derived from each virus is not particularly limited, but the influenza vaccine may preferably contain equal amounts of antigens derived from each virus.
The influenza vaccine and the vaccine stock solution may contain a pharmaceutically acceptable carrier as necessary. As the pharmaceutically acceptable carrier, a carrier used to produce a vaccine can be used without limitation, and specifically, saccharides, inorganic salts, buffered saline, dextrose, water, glycerol, isotonic aqueous buffer solutions, surfactants, emulsifiers, preservatives, isotonizing agents, pH adjusters, deactivating agents, and a combination of two or more kinds thereof are appropriately blended.
The influenza vaccine and the vaccine stock solution may contain an immunopotentiator (adjuvant). Examples of the adjuvant include a mineral-containing composition, an oily emulsion, a saponin composition, a virosome, virus-like particles (VLP), and a bacterial or microbial derivative (such as a non-toxic derivative of Enterobacteriaceae lipopolysaccharide, a lipid A derivative, immunostimulatory oligonucleotide ADP ribosylated toxin, or a detoxification derivative thereof).
The content of the influenza vaccine in the entire needle portion is not particularly limited, but is preferably in a range of 0.01 μg to 200 μg in terms of the content of HA per preparation. The content thereof is more preferably in a range of 1 μg to 100 μg. HA is an abbreviation for hemagglutinin.
The mass ratio between the drug and the water-soluble polymer in the needle portion is not particularly limited, but is preferably in a range of 1/0.5 to 1/10 and more preferably in a range of 1/0.5 to 1/4.
In the present invention, the needle portions contain meglumine or a salt thereof. Further, meglumine is also referred to as methyl glucamine (N-methyl-D-glucamine).
Specific examples of the salt of meglumine include a hydrochloride, a sulfate, a carboxylate, a borate, a methanesulfonate, a p-toluenesulfonate, and an ascorbate. Among these, a hydrochloride is preferable.
The content of the meglumine or the salt thereof in the needle portions is preferably in a range of 0.01 times to 300 times the content of the influenza vaccine and more preferably in a range of 0.5 times to 3 times the content of the influenza vaccine.
The needle portions may further contain a soluble additive.
Examples of the soluble additive include saccharides.
As the saccharides, one or more of monosaccharides, disaccharides, oligosaccharides, and polysaccharides can be used. It is preferable that disaccharides can be added to the needle portions. Examples of the disaccharides include sucrose, lactulose, lactose, maltose, trehalose, and cellobiose. Among these, sucrose, maltose, and trehalose are particularly preferable.
In a case where the needle portions contain a soluble additive, the mass ratio between the drug (influenza vaccine) and the soluble additive is not particularly limited, but is preferably in a range of 1/0.1 to 1/10 and more preferably in a range of 1/0.5 to 1/3.
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto.
The needle portion 112 has a conical shape in
It is preferable that the microneedle array according to the embodiment of the present invention has a shape of the microneedle 110 of
The needle first layer 112A illustrated in
In the microneedle array according to the embodiment of the present invention, it is preferable that needle portions are arranged at intervals of approximately 0.1 to 10 needles per 1 mm in a row. It is more preferable that the microneedle array has 1 to 10000 microneedles per 1 cm2. In a case where the density of microneedles is set to 1 needle/cm2 or greater, the microneedles can efficiently puncture the skin. Further, in a case where the density of the microneedles is set to 10000 needles/cm2 or less, the microneedle array can sufficiently puncture the skin. The density of needle portions is preferably in a range of 10 to 5000 needles/cm2, more preferably in a range of 25 to 1000 needles/cm2, and particularly preferably in a range of 25 to 400 needles/cm2.
The microneedle array according to the embodiment of the present invention can be supplied in a sealed storage form together with a drying agent. As the drying agent, known drying agents (such as silica gel, calcined lime, calcium chloride, silica alumina, and a sheet-like drying agent) can be used.
[Method of Producing Microneedle Array]
According to the present invention, there is provided a method of producing the microneedle array according to the embodiment of the present invention, including a step of concentrating influenza vaccine, a step of forming needle portions using the concentrated influenza vaccine obtained in the above-described step, and a step of forming a sheet portion.
It is preferable that the step of concentrating the influenza vaccine is a step of concentrating the influenza vaccine by centrifugation.
In the present invention, the needle portions can be formed by filling a mold with a liquid containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof.
The microneedle array according to the embodiment of the present invention can be produced in conformity with the methods described in, for example, JP2013-153866A or WO2014/077242A.
(Preparation of Mold)
According to the first method, a Si substrate is coated with a photoresist, exposed, and then developed. Further, an array of shaped portions 12 having a conical shape (projection) is prepared on the surface of the original plate 11 by performing etching using reactive ion etching (RIE) or the like. In a case where the etching such as RIE or the like is performed so as to form shaped portions having a conical shape on the surface of the original plate 11, the portions having a conical shape can be formed by performing etching in an oblique direction while the Si substrate rotates. According to the second method, an array of the shaped portions 12 having a square pyramid shape or the like is formed on the surface of the original plate 11 by performing processing on a metal substrate such as Ni using a cutting tool such as a diamond bit.
Next, a mold is prepared. Specifically, a mold 13 is prepared using the original plate 11 as illustrated in
According to the first method, a silicone resin obtained by adding a curing agent to polydimethylsiloxane (PDMS, for example, SYLGARD 184 (registered trademark, manufactured by Dow Corning Toray Co., Ltd.)) is poured into the original plate 11, subjected to a heat treatment at 100° C., cured, and peeled off from the original plate 11. According to the second method, an ultraviolet (UV) cured resin which is cured by being irradiated with ultraviolet rays is poured into the original plate 11, irradiated with ultraviolet rays in a nitrogen atmosphere, and peeled off from the original plate 11. According to the third method, a solution obtained by dissolving a plastic resin such as polystyrene or polymethyl methacrylate (PMMA) in an organic solvent is poured into the original plate 11 coated with a peeling agent, dried so that the organic solvent is volatilized, and cured, and then peeled off from the original plate 11. According to the fourth method, an inverted product is produced using Ni electroforming.
In this manner, the mold 13 formed by needle-like recesses 15, which have an inverted shape of the conical shape or the pyramid shape of the original plate 11, being two-dimensionally arranged is prepared. The mold 13 prepared in the above-described manner is illustrated in
As illustrated in the (A) portion of
In a case where such a mold complex 18 is used, only the air present in the needle-like recess 15 can be released from the needle-like recess 15 without permeation of the polymer-dissolved solution filling the needle-like recess 15. In this manner, the property of transferring the shape of the needle-like recess 15 to a polymer is excellent and a sharper needle portion can be formed.
A diameter D (diameter) of the air vent hole 15C is preferably in a range of 1 to 50 μm. In a case where the diameter D of the air vent hole 15C is less than 1 μm, the air vent hole 15C cannot be sufficiently used as an air vent hole. Further, in a case where the diameter D of the air vent hole 15C is greater than 50 μm, the sharpness of the tip of a formed microneedle is damaged.
As the gas permeating sheet 19 formed of a material that permeates a gas and does not permeate a liquid, for example, a gas permeating film (POREFLON (registered trademark), FP-010, manufactured by Sumitomo Electric Industries, Ltd.) can be suitably used.
As the material used for the mold 13, an elastic material or a metal material can be used. Among these, an elastic material is preferable and a material having a high gas permeability is more preferable. The oxygen permeability, which is a representative example of the gas permeability, is preferably 1×10−12 (mL/s·m2·Pa) or greater and more preferably 1×10−10 (mL/s·m2·Pa) or greater. Further, 1 mL is 10−6 m3. In a case where the gas permeability is in the above-described range, the air present in a recess of the mold 13 can be released from the mold and a microneedle array with less defects can be produced. Specific examples of such materials include materials obtained by melting or dissolving, in a solvent, a silicone resin (for example, SYLGARD 184 (registered trademark, manufactured by Dow Corning Toray Co., Ltd.) or KE-1310ST (product number, manufactured by Shin-Etsu chemical Co., Ltd.)), a UV curable resin, or a plastic resin (for example, polystyrene or polymethyl methacrylate (PMMA)). Among these, a silicone rubber-based material is preferable since the material has durability to transfer resulting from repetitive pressure and has excellent peeling properties with respect to a material. Further, examples of the metal material include Ni, Cu, Cr, Mo, W, Ir, Tr, Fe, Co, MgO, Ti, Zr, Hf, V, Nb, Ta, a-aluminum oxide, zirconium oxide, stainless steel (for example, STAVAX (registered trademark) of Bohler-Uddeholm KK), and alloys thereof. As the material of a frame, the same material as the material of the mold 13 can be used.
(Water-Soluble Polymer-Dissolved Solution)
In the present invention, it is preferable to prepare a water-soluble polymer-dissolved solution containing influenza vaccine and meglumine or a salt thereof used to form at least a part of a needle portion and a water-soluble polymer-dissolved solution used to form the sheet portion.
The type of water-soluble polymer is as described in the present specification above.
Disaccharides may be mixed into the water-soluble polymer-dissolved solution, and the kind of the disaccharides is as described in the present specification above.
Further, the solvent used for dissolution may be a solvent other than water as long as the solvent has volatility, and methyl ethyl ketone (MEK), an alcohol, or the like can be used as the solvent.
Specifically, the water-soluble polymer-dissolved solution containing a drug and meglumine or a salt thereof used to form at least a part of a needle portion is a liquid containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof.
The concentration of the influenza vaccine in the liquid containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof is not particularly limited, but is preferably in a range of 0.001 mg/mL to 100 mg/mL and more preferably in a range of 0.1 mg/mL to 20 mg/mL.
The concentration of the meglumine in the liquid containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof is not particularly limited, but is preferably in a range of 0.001 mg/mL to 100 mg/mL and more preferably in a range of 0.1 mg/mL to 20 mg/mL.
The concentration of the water-soluble polymer in the liquid containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof is not particularly limited, but is preferably in a range of 1 mg/mL to 100 mg/mL and more preferably in a range of 5 mg/mL to 50 mg/mL.
(Formation of Needle Portion)
As illustrated in
As the material used for the nozzle 34, an elastic material or a metal material can be used. Examples thereof include TEFLON (registered trademark), stainless steel (steel special use stainless (SUS)), and titanium.
As illustrated in
In a case where the mold 13 is formed of a material having a gas permeability, the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof can be suctioned by suctioning the solution from the rear surface of the mold 13, and the filling of the needle-like recesses 15 with the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof can be promoted.
Next to the filling step with reference to
Since the lip portion 34A of the nozzle 34 is brought into contact with the surface of the mold 13 and then the movement is made, the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof, which remains on the surface of the mold 13 other than the needle-like recesses 15 can be collected by the nozzle 34. It is possible to prevent the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof from remaining on the mold 13 other than the needle-like recesses 15.
In order to reduce the damage to the mold 13 and suppress deformation due to compression of the mold 13 as much as possible, it is preferable that the pressing pressure of the nozzle 34 against the mold 13 is set to be as small as possible during the movement. Further, in order to prevent the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof from remaining on the surface of the mold 13 other than the needle-like recesses 15, it is preferable that at least one of the mold 13 or the nozzle 34 is formed of a flexible material which can be elastically deformed.
By repeating the filling step of
The above-described filling step and moving step may be carried out in a mode (1) in which the needle-like recesses 15 are filled with the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof while the nozzle 34 is moved or in a mode (2) in which the nozzle 34 is temporarily stopped on the needle-like recesses 15 during the movement of the nozzle 34, the needle-like recesses 15 are filled with the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof, and the nozzle 34 is moved again after the filling. The lip portion 34A of the nozzle 34 is brought into contact with the surface of the mold 13 between the filling step and the moving step.
In a case where the filling of the plurality of needle-like recesses 15 which are 5 rows and 5 columns of needle-like recesses is completed, the nozzle 34 is moved to the plurality of adjacent needle-like recesses 15 which are 5 rows and 5 columns of needle-like recesses. In regard to the liquid supply, in a case where the nozzle 34 is moved to the plurality of needle-like recesses 15 formed of 5 rows and 5 columns of adjacent needle-like recesses, it is preferable that the supply of the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof is stopped. There is a distance between the needle-like recesses 15 in the fifth row and the needle-like recesses 15 in the next first row. In a case where the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof is continuously supplied during the movement of the nozzle 34 between the rows, the liquid pressure inside of the nozzle 34 is extremely high in some cases. As the result, the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof supplied from the nozzle 34 may flow out of the needle-like recesses 15 of the mold 13. In order to suppress the flowing out of the solution, it is preferable that the liquid pressure inside the nozzle 34 is detected and the supply of the water-soluble polymer-dissolved solution 22 containing a drug and meglumine or a salt thereof is stopped in a case where it is determined that the liquid pressure is extremely high.
Further, the method of supplying the water-soluble polymer-dissolved solution containing a drug and meglumine or a salt thereof using a dispenser that has a nozzle has been described, but bar coating, spin coating, spray coating, or the like can be applied in addition to the coating with the dispenser.
In the present invention, it is preferable that a drying treatment is performed after the water-soluble polymer-dissolved solution containing influenza vaccine and meglumine or a salt thereof to the needle-like recesses. That is, it is preferable that the method of producing the microneedle array according to the embodiment of the present invention includes a drying step of drying the solution after the filling step of filling the mold with the solution containing influenza vaccine, a water-soluble polymer, and meglumine or a salt thereof.
Further, it is preferable that the method of producing the microneedle array according to the embodiment of the present invention includes a step of coating the mold after the drying step with the water-soluble polymer-dissolved solution. That is, as one preferred example of the method of producing the microneedle array according to the embodiment of the present invention, a method including a step of drying a mold for forming needle portions filled with a first water-soluble polymer-dissolved solution containing influenza vaccine and meglumine or a salt thereof to form a part of the needle portions; and a step of filling the upper surfaces of the part of the needle portions which have been formed in the above-described manner with a second water-soluble polymer-dissolved solution and drying the mold can be exemplified.
It is preferable that the condition for drying the mold for forming needle portions filled with the first water-soluble polymer-dissolved solution containing influenza vaccine and meglumine or a salt thereof is set to be a condition that the water content of the first water-soluble polymer-dissolved solution reaches 20% or less after 30 to 300 minutes from the start of the drying of the mold.
It is particularly preferable that the drying can be controlled such that the temperature is held to be lower than or equal to a temperature at which the drug does not lose the effect and the water content of the water-soluble polymer-dissolved solution reaches 20% or less after 60 minutes or longer from the start of the drying of the mold.
As a method of controlling the drying rate, any method of delaying the drying, such as the temperature, the humidity, the drying air volume, the use of a container, and the volume and/or the shape of a container, can be employed.
It is preferable that the drying can be performed in a state where the mold for forming needle portions filled with the first water-soluble polymer-dissolved solution containing a drug is covered with a container or accommodated in a container.
The temperature during the drying is preferably in a range of 1° C. to 45° C. and more preferably in a range of 1° C. to 40° C.
The relative humidity during the drying is preferably in a range of 10% to 95%, more preferably in a range of 20% to 95%, and still more preferably in a range of 30% to 95%.
(Formation of Sheet Portion)
Several embodiments of a step of forming the sheet portion will be described.
A first embodiment of a step of forming the sheet portion will be described with reference to
In the first embodiment, in order to promote the filling of the needle-like recesses 15 with the water-soluble polymer-dissolved solution 22 containing influenza vaccine and meglumine or a salt thereof and the water-soluble polymer-dissolved solution 24, it is preferable to apply a pressure from the surface of the mold 13 and perform suctioning from the rear surface of the mold 13 under reduced pressure.
Next, a second embodiment will be described with reference to
In the second embodiment, in order to promote the filling of the needle-like recesses 15 with the water-soluble polymer-dissolved solution 24, it is also preferable to apply a pressure from the surface of the mold 13 and perform suctioning from the rear surface of the mold 13 under reduced pressure.
The method of drying the water-soluble polymer-dissolved solution 24 is not limited as long as the method includes a step of volatilizing the solvent in the polymer-dissolved solution. The method is not particularly limited, and a method of performing heating, blowing air, or decompression may be used. The drying treatment can be performed under the conditions of 1° C. to 50° C. for 1 to 72 hours. Examples of the method of blowing air include a method of blowing hot air at 0.1 to 10 msec. It is preferable that the drying temperature is a temperature at which the drug in the polymer-dissolved solution 22 containing a drug is not thermally degraded.
(Peeling)
A method of peeling the microneedle array from the mold 13 is not particularly limited. It is preferable that needle portions are not bent or broken during the peeling. Specifically, a sheet-like base material 40 on which a pressure-sensitive adhesive layer is formed is attached onto the microneedle array and then the base material 40 can be peeled off from the end portion such that the base material 40 is turned over as illustrated in
The method of producing the microneedle array according to the embodiment of the present invention is not particularly limited, but it is preferable that the microneedle array is obtained by a production method including a step (1) of producing a mold, a step (2) of preparing a water-soluble polymer-dissolved solution containing influenza vaccine and meglumine or a salt thereof, a step (3) of filling the mold with the solution obtained in the step (2) to form upper end portions of the needle portions, a step (4) of filling the mold with a water-soluble polymer to form lower end portions of the needle portions and a sheet portion, and a step (5) of peeling the microneedle array from the mold.
Hereinafter, the present invention will be described in more detail with reference to examples of the present invention. Further, the materials, the use amounts, the ratios, the treatment contents, the treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitatively interpreted by the specific examples described below.
<Preparation of Microneedle Array Containing Influenza Vaccine>
(Production of Mold)
An original plate 11 was prepared by arranging shaped portions 12 having a needle-like structure, on which a cone 52 with a diameter D2 of 340 μm and a height H2 of 834 μm was formed on a truncated cone 50 having a bottom surface with a diameter D1 of 800 μm and having a height H1 of 200 μm, on the surface of a smooth Ni plate having one side with a length of 40 mm, as illustrated in
(Preparation of Influenza Vaccine Concentrate)
The influenza vaccine stock solution was poured into a container for exclusive use for ultracentrifugation, and the influenza vaccine was allowed to be precipitated by ultracentrifugation (conditions: 131,491×g, 90 minutes, 4° C.). The supernatant was disposed of, phosphate buffered saline (PBS) was added thereto so that the mixture was vortexed, and the resultant was allowed to stand at 4° C. overnight, thereby preparing an influenza vaccine concentrate.
(Preparation of Water-Soluble Polymer-Dissolved Solution Containing Influenza Vaccine and Meglumine)
An aqueous solution obtained by mixing the influenza vaccine concentrate, a water-soluble polymer, meglumine (FUJIFILM Wako Pure Chemical Corporation), saccharides, and Tween (registered trademark) 80 (MERCK) was prepared to obtain a water-soluble polymer-dissolved solution containing the influenza vaccine. As the water-soluble polymer, hydroxyethyl starch (HES) (Fresenius Kabi) and chondroitin sulfate (CS) (Maruha Nichiro Corporation) were used. As the saccharides, sucrose (Suc) (Japanese Pharmacopoeia grade, FUJIFILM Wako Pure Chemical Corporation), trehalose (Tre) (Hayashibara), and glucose (Japanese Pharmacopoeia grade, FUJIFILM Wako Pure Chemical Corporation) were used. The formulation of each solution is as listed in Tables 1, 2, and 3 below. The content of the influenza vaccine in Tables 1 and 3 was set to 9 mg per 1 mL. The content of the influenza vaccine in Table 2 was set to 0.3 mg per 1 mL.
(Preparation of Water-Soluble Polymer-Dissolved Solution Forming Sheet Portion)
Chondroitin sulfate (Maruha Nichiro Corporation) was dissolved in water to prepare a water-soluble polymer-dissolved solution forming a sheet portion.
(Filling and Drying of Polymer-Dissolved Solution Containing Drug)
A filling device illustrated in
A gas-permeating film having one side with a length of 15 mm (POREFLON (registered trademark), FP-010, Sumitomo Electric Industries, Ltd.) was placed on a horizontal suction stand, and a mold was placed on the film such that the surface of the mold was directed to the upper side. The gas-permeating film and the mold were fixed to the vacuum stand by reducing the pressure with a suction pressure of a gauge pressure of 90 kPa in the rear surface direction of the mold.
A stainless steel (SUS) nozzle having a shape as illustrated in
The mold filled with the water-soluble polymer-dissolved solution containing influenza vaccine was allowed to stand in an environment of a temperature of 23° C. and a relative humidity of 45% and dried.
(Formation and Drying of Sheet Portion)
The water-soluble polymer-dissolved solution forming the sheet portion was developed on the mold suctioning the solution in a state where the mold filled with the water-soluble polymer solution containing influenza vaccine was placed on a vacuum stand and sucked under reduced pressure. The suction was stopped after 60 minutes from the addition of the water-soluble polymer-dissolved solution, and the mold was allowed to stand in an environment of a temperature of 23° C. and a relative humidity of 45% and dried.
(Peeling)
The dried and solidified microneedle array was carefully peeled off from the mold to form a microneedle array containing influenza vaccine. Each microneedle is formed of a frustum portion and a needle portion. The height of a needle is approximately 800 μm and the width of a base portion is approximately 320 μm, and the frustum portion has a truncated cone structure such that the height thereof is approximately 160 μm, the diameter of the upper bottom surface thereof is approximately 320 μm, and the diameter of the lower bottom surface thereof is approximately 780 μm. The thickness of the sheet portion is approximately 200 μm, the number of needles is 100, the interval between needles is approximately 1 mm, and the needles are arranged in a square shape.
<Evaluation of Microneedle Array>
(Quantification of Content of Influenza Vaccine in Microneedle)
(a) Content in Microneedle from Needle Tip to 600 μm
Each needle portion of a microneedle having a needle length of 800 μm was cut at a position of 800 μm from the needle tip using a cutter blade. The cut needle portions were collected in a 1.5 mL tube. 0.5 mL of phosphate buffer was added to a 1.5 mL tube including the collected needle portions and stirred to dissolve the needle portions. The solution in which the needle portions were dissolved was diluted with phosphate buffer to have an appropriate concentration, and the content of the influenza vaccine contained in the cut needle portions was quantified according to an enzyme-linked immunosorbent assay (ELISA) method.
(b) Content in Microneedle from Needle Tip to 800 μm
Each remaining needle portion cut at 600 μm from the tip was cut at a position of the boundary between the needle portion and the frustum portion using a cutter blade. The remaining cut needle portions were collected in a 1.5 mL tube. 0.5 mL of phosphate buffer was added to a 1.5 mL tube including the collected needle portions and stirred to dissolve the needle portions. The solution in which the needle portions were dissolved was diluted with phosphate buffer to have an appropriate concentration, and the content of the influenza vaccine contained in the cut needle portions was quantified according to the ELISA method.
The total content obtained by adding the quantified content of influenza vaccine in the remaining needle portions to the content of influenza vaccine in the microneedles from the needle tips to 600 μm which had been quantified in (a) described above was set as the content of influenza vaccine in the microneedles from the needle tips to 800 μm.
The region from the needle tip to 600 μm of a microneedle and the region from the needle tip to 800 μm of the microneedle are illustrated in
In each microneedle array, the acquired results for the tip filling rate based on the following equation are listed in Tables 1, 2, and 3 below.
Tip filling rate=content of influenza vaccine in microneedle from needle tip to 600 μm/content of influenza vaccine in microneedle from needle tip to 800 μm
(Stability of Content of Influenza Vaccine in Microneedle)
The produced influenza vaccine-including microneedle array was allowed to stand at 35° C. for 3 days. After the standing, the microneedle array was removed, and the content of the vaccine was investigated. The content of the vaccine was evaluated according to the ELISA method.
The content of the vaccine after the standing at 35° C. for 3 days to the content of the vaccine immediately after the production was set as the vaccine residual rate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-034107 | Feb 2019 | JP | national |
This application is a Continuation of PCT International Application No. PCT/JP2020/007559 filed on Feb. 26, 2020, which claims priority under 35 U.S.C § 119(a) to Japanese Patent Application No. 2019-034107 filed on Feb. 27, 2019. Each of the above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2020/007559 | Feb 2020 | US |
| Child | 17412388 | US |
