METHOD FOR PRODUCING MICROPARTICLES

Abstract

The present invention has an object providing microparticles having an average particle size of 100 μm or less.

The present invention provides microparticles having an average particle size of 100 μm or less and a method for producing thereof. In addition, the present invention provides medicine, food and feedstuff comprising the microparticles having an average particle size of 100 μm or less.

Claims

1-14. (canceled)

15. Microparticles having a diameter of 100 μm or less, produced by a method comprising the steps of: simultaneously spraying an active element, a matrix-forming component A and a matrix-forming component B that can bind with the matrix-forming component A; and collecting microparticles having the active element carried in a polymer structure formed with the bound components A and B.

16. Medicine, feedstuff or food comprising the microparticles according to claim 15.

17. The microparticles of claim 15, wherein the active element and the matrix-forming component A are contained in a first solution, and the matrix-forming component B is contained in a second solution.

18. The microparticles of claim 15, wherein the active element and the matrix-forming component B are contained in a first solution, and the matrix-forming component A is contained in a second solution.

19. The microparticles of claim 15, wherein the active element, the matrix-forming component A and the matrix-forming component B are contained in first to third solutions, respectively.

20. The microparticles of claim 15, wherein the active element and the matrix-forming component A are contained in a first solution, and the active element and the matrix-forming component B are contained in a second solution.

21. The microparticles of claim 17, wherein the each solution is sprayed from each nozzle.

22. The microparticles of claim 15, wherein the active element is a protein and/or a peptide.

23. The microparticles of claim 15, wherein the active element comprises at least one component selected from the group consisting of: bovine lactoferrin, human lactoferrin, recombinant bovine lactoferrin, recombinant human lactoferrin, lactoperoxidase, lysozyme, ribonuclease, TGFβ, angiogenin, interferons, interleukins, granular colony-stimulating factor, erythropoietin, lactoferricin, insulin, insulin analogs, insulin derivatives, GLP-1, GLP-1 analogs, GLP-1 derivatives, glucagon luteinizing hormone-releasing hormone, leuprorelin, calcitonin, vasopressin and active fragments thereof.

24. The microparticles of claim 15, wherein the matrix-forming component A comprises a compound having a cationic dissociable group.

25. The microparticles of claim 15, wherein the matrix-forming component B comprises a compound having an anionic dissociable group.

26. The microparticles of claim 15, wherein the matrix-forming component A comprises at least one component selected from the group consisting of: chitosan, chitosan oligosaccharide, polylysine, polyarginine, spermidine, putrescine, lysine, arginine, calcium chloride and calcium lactate.

27. The microparticles of claim 26, wherein a component of the matrix-forming component A is in a form of sodium salt, magnesium salt or calcium salt.

28. The microparticles of claim 15, wherein the matrix-forming component B comprises at least one component selected from the group consisting of: inositol-6-phosphate, citric acid, alginic acid, low-molecular-weight alginic acid, hyaluronic acid, pectin, carboxymethyl cellulose, carrageenan, aspartic acid, glutamic acid, deoxyribonucleic acid, oligodeoxynucleotide, deoxynucleotide, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, polyaspartic acid, polylactic acid, polyglutamic acid, malic acid, tartaric acid and succinic acid.

29. The microparticles of claim 28, wherein a component of the matrix-forming component B is in a form of sodium salt, magnesium salt or calcium salt.

30. The microparticles of claim 15, wherein the active element and the matrix-forming component B are contained in a first solution, and the matrix-forming component A is contained in a second solution, and wherein the each solution is sprayed from each nozzle.

31. The microparticles of claim 15, wherein the active element, the matrix-forming component A and the matrix-forming component B are contained in first to third solutions, respectively, and wherein the each solution is sprayed from each nozzle.

32. The microparticles of claim 15, wherein the active element and the matrix-forming component A are contained in a first solution, and the active element and the matrix-forming component B are contained in a second solution, and wherein the each solution is sprayed from each nozzle.

33. The microparticles of claim 15, wherein the matrix-forming component A and the matrix-forming component B are contained in different solution, and the active element is contained only in a solution that contains the matrix-forming component A, or only in a solution that contains the matrix-forming component B, or only in a solution that does not contain the matrix-forming components A and B, or in a solution that contains the matrix-forming components A and B.

34. The microparticles of claim 15, having a diameter of 50 μm or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 is a graph showing the results from dissolution tests of macroparticles produced according to a method employing a conventional technique (solid line) and microparticles produced according to a method of the present invention (dashed line).

[0039] FIG. 2 is a graph showing a particle size distribution of the microparticles of the present invention.

[0040] FIG. 3 is a graph showing a particle size distribution of the macroparticles produced according to the method employing the conventional technique.

[0041] FIG. 4 is the electrophoresis pattern showing the results from SDS-PAGE analysis of the contents recovered from the small intestine of rat models.

[0042] FIG. 5 is a graph showing a particle size distribution of the microparticles of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

[0043] Hereinafter, the present invention will be described in detail. The following embodiments are just examples for illustrating the present invention, and the present invention is not intended to be limited to these embodiments. The present invention may be carried out in various embodiments without departing from the scope of the invention.

[0044] All References, unexamined patent applications, patent publications and other patent References cited herein, are incorporated herein by reference. In addition, the present specification incorporates the contents of the specification and drawings of Japanese Patent Application No. 2013-171688 filed on Aug. 21, 2013, which serves as the basis for claiming priority of the present application.

[0045] 1. Method for Producing Microparticles

[0046] The present inventors found that very fine microparticles with an average particle size of 100 μm or less can be formed by simultaneously spraying an active element(s), a matrix-forming component A and a matrix-forming component B that can bind with the matrix-forming component A.

[0047] Thus, the present invention provides a method for producing microparticles with a diameter of 100 μm or less (hereinafter, referred to as a “method of the present invention”), wherein the method comprises the steps of:

[0048] simultaneously spraying an active element(s), a matrix-forming component A and a matrix-forming component B that can bind with the matrix-forming component A; and

[0049] collecting microparticles having the active element(s) carried in a polymer structure formed with the bound components A and B.

[0050] According to a method of the present invention, an active element(s), a matrix-forming component A and a matrix-forming component B are preferably contained in solutions or suspensions (hereinafter, “a solution or a suspension” is collectively referred to as a “solution”, which means that the term “solution” as used in the present application may include both solution and suspension). However, since the matrix-forming component A and the matrix-forming component B have the property of binding to each other, they need to be contained in separate solutions.

[0051] Examples of solutions containing an active element(s), a matrix-forming component A or a matrix-forming component B include the following cases.

(1) A case where the active element(s) and the matrix-forming component A are contained in a first solution, and the matrix-forming component B is contained in a second solution.
(2) A case where the active element(s) and the matrix-forming component B are contained in a first solution, and the matrix-forming component A is contained in a second solution.
(3) A case where the active element(s), the matrix-forming component A and the matrix-forming component B are contained in first to third solutions, respectively.
(4) A case where the active element(s) and the matrix-forming component A are contained in a first solution, and the active element(s) and the matrix-forming component B are contained in a second solution.

[0052] In the above-mentioned cases (1)-(4), the active element(s) may be of a single type or multiple types. In particular, in case (4), the active element(s) contained in the first solution and the active element(s) contained in the second solution may be the same or different.

[0053] A usual atomizer can be used to spray the solutions.

[0054] Herein, the phrase “simultaneous spraying” does not necessarily mean that they are physically sprayed at the same time, and a certain amount of time lag may occur as long as a mist of the mixture of the active element(s), the matrix-forming component A and the matrix-forming component B is formed.

[0055] Thus, the step of “simultaneously spraying” may be:

(i) an embodiment where an active element(s), a matrix-forming component A and a matrix-forming component B are mixed after being discharged from the nozzles of the atomizer (hereinafter, referred to as a “post-spray mixing process”); or
(ii) an embodiment where an active element(s), a matrix-forming component A and a matrix-forming component B are mixed before spraying, and the resulting mixture is immediately sprayed (hereinafter, referred to as a “post-mixing spraying process”).

[0056] (i) Post-Spray Mixing Process

[0057] Examples of a post-spray mixing process will be described based on the cases (1)-(4) above, but the present invention is not limited thereto. Conditions for “simultaneously spraying” are fulfilled the requirements when a second solution (and a third solution) is sprayed while a mist of a first solution stays in the air so that mists of both solutions (or all of the solutions) make contact in the air.

[0058] Here, the term “contact” does not necessarily mean that the mists are entirely brought into contact. Accordingly, the state of “contact” as used with the present invention is accomplished as long as the mists are partially brought into contact. This is because microparticles of the present invention can be formed even by partial contact.

[0059] Moreover, the phrase “in the air” means that droplets in the mist are in a rising or falling state due to the propellant force and in a free-falling state due to gravity. Specifically, the phrase means that the droplets in the mist are in a state where they are not supported by a reservoir, floor or the like.

[0060] Now, in the post-spray mixing process, the respective components are mixed while being contained in the droplets of mists. This mixing is immediately accomplished by bringing the mists of the respective solutions into contact.

[0061] The time that takes from spraying to contact is within a second, preferably within 900 milliseconds, within 800 milliseconds, within 700 milliseconds, within 600 milliseconds or within 500 milliseconds.

[0062] The active element(s), the matrix-forming component A and the matrix-forming component B are mixed together upon contact, where the matrix-forming components A and B immediately react with each other to form a cross-link. The active element(s) is retained in this cross-linked structure, thereby forming microparticles of the present invention. Specifically, microparticles of the present invention are immediately formed once the active element(s) and the matrix-forming components A and B are brought into contact.

[0063] (ii) Post-Mixing Spraying Process

[0064] In the post-mixing spraying process, an active element(s), a matrix-forming component A and a matrix-forming component B are mixed before spraying. Therefore, the matrix-forming components A and B may possibly be initiating the binding reaction at the time of spraying.

[0065] However, if the time between mixing and spraying is sufficiently short, the mixture can be sprayed before the binding reaction between components A and B is completed, in which case the binding reaction would be completed after the spraying.

[0066] Accordingly, microparticles of the present invention can be formed by the post-mixing spraying process if the time between mixing and spraying is sufficiently short.

[0067] Hence, conditions for “simultaneously spraying” are fulfilled the requirements for the post-mixing spraying process as long as microparticles having the active element(s) carried in polymer structures formed with the bound components A and B are formed.

[0068] The time that takes between mixing to spraying is less than 100 ms, less than 90 ms, less than 80 ms, less than 70 ms, less than 60 ms, less than 50 ms, less than 40 ms, less than 30 ms, less than 20 ms, less than 10 ms or less than 5 ms.

[0069] Once the matrix-forming components A and B are mixed, they immediately react with each other to form a cross-link. The active element(s) is retained in this cross-linked structure, thereby forming microparticles of the present invention. Specifically, microparticles of the present invention are immediately formed once the active element(s) and the matrix-forming components A and B are brought into contact.

[0070] Furthermore, the (microscopic) structure of the microparticles of the present invention will specifically be described. One of the characteristics of the microparticles of the present invention is their size. An average particle size of the particles as observed by laser diffractometry or with an electronic microscope is 100 μm or less. The term “average particle size” as used herein refers to a particle size at an integrated value of 50% of the equivalent sphere diameters obtained by a microscopic or laser diffractometry method. Although particles may be produced into various shapes such as a sphere, an ellipsoid, a biconvex lens shape, a hemispherical shape, a partially opened sphere or hemisphere, or a porous body thereof, 90% or more of the microparticles produced by the same production method in the same lot have the same shape.

[0071] Additionally, the microparticles of the present invention are characteristic in that an active element(s) is carried in a matrix structure that is formed through reaction between the matrix-forming components A and B.

[0072] Preferably, a method of the present invention is carried out by a post-spray mixing process.

[0073] Moreover, in any of the above-mentioned cases (1)-(4), the solutions are preferably each sprayed from separate nozzles.

[0074] Preferably, the respective solutions are simultaneously sprayed by an atomizer(s) with closely arranged multiple nozzles. Thus, the respective solutions will make contact with each other in mist states.

[0075] An example of an atomizer with closely arranged multiple nozzles includes a spray dryer provided with three-fluid nozzles (B290 apparatus from Buchi equipped with nozzles under model number 46555). This spray dryer has nozzles for two types of liquids as well as compressed gas.

[0076] In addition, four-fluid nozzles (for example, FIGS. 3, 4, and 5) described in Japanese Patent No. 2797080 (page 6, lines 5-47) can also be used. The four-fluid nozzles can spray two types of liquids from two nozzles and gas from the remaining two nozzles.

[0077] Furthermore, Japanese Unexamined Patent Application Publication No. 2003-117442 (page 5, line 19 to page 8, line 47) describes a method for bringing jets of two types of solutions into contact by allowing them to collide with each other at a collision angle of 45-150° (FIGS. 1 and 2). The “contact” state of the present invention can also be achieved by this method.

[0078] Examples of atomizers that can achieve “simultaneous spraying” as referred to by the present invention include B-290 equipped with nozzles under model number 46555 from Nihon Buchi, as well as MDL-050B and 050C (Fujisaki Electric) equipped with three-fluid and four-fluid nozzles, NL-5 (Ohkawara Kakohki) equipped with TwinJet nozzles RJ0TLM1, and RL-5 (Ohkawara Kakohki) equipped with TwinJet nozzles RJ-10.

[0079] In particular, NL-5 (Ohkawara Kakohki) and RL-5 (Ohkawara Kakohki) can be used to easily carry out the post-mixing spraying process.

[0080] The formed microparticles may be directly collected or collected after a drying treatment.

[0081] The drying process may be simultaneously or concurrently performed with spraying. Specifically, in order to perform the drying process simultaneously or concurrently with spraying, the spraying step is carried out under the same atmospheric conditions for drying the microparticles. For example, the above-mentioned atomizer can be used to simultaneously perform the drying treatment with spraying.

[0082] Conditions for the drying treatment may be appropriately selected from −197° C. to +250° C. In one embodiment, an inlet temperature of a spray dryer is adjusted to 100-300° C., preferably 120-250° C., and more preferably 150-220° C. An outlet temperature is adjusted to 30° C. or higher, preferably 40° C. or higher, and more preferably 45° C. or higher. In this case, the atmospheric pressure is adjusted to 0-1 atm. While spray drying is usually carried out under the atmospheric pressure conditions (1 atm), spray drying under reduced pressure will be performed under the conditions in which the pressure is reduced with a vacuum pump.

[0083] Alternatively, when an active element(s) is a thermally-labile substance, the microparticles may be collected in a precipitated state by cooling immediately after spraying by a method such as spray chilling or spray lyophilization. Alternatively, the cooling may be simultaneously or concurrently performed with spraying. Specifically, in order to perform the cooling process simultaneously or concurrently with spraying, the spraying step is carried out under the same atmospheric conditions for cooling the microparticles.

[0084] Conditions for the cooling step would be a temperature of 30-70° C. in the case of spray chilling, while, in the case of spray lyophilization, the microparticles are cooled or frozen at a temperature of −196 to 0° C. with liquid nitrogen or a cooling equipment or through self-freezing phenomenon by evaporation of water. The atmospheric pressure is adjusted to 0-1 atm. While an atmospheric pressure (1 atm) is employed in the case of spray chilling, a vacuum to an atmospheric pressure is employed in the case of spray lyophilization.

[0085] The microparticles of the present invention can be used for various purposes according to a physiological action of an active element.

[0086] While an active element used with a method of the present invention is not particularly limited as long as it is a physiologically active compound, it is preferably a protein or a peptide.

[0087] Examples of peptide used with a method of the present invention include bovine lactoferrin, human lactoferrin, recombinant bovine lactoferrin, recombinant human lactoferrin, lactoperoxidase, lysozyme, ribonuclease, TGFβ, angiogenin, interferons, interleukins, granular colony-stimulating factor, erythropoietin, lactoferricin, insulin, insulin analogs, insulin derivatives, GLP-1, GLP-1 analogs, GLP-1 derivatives, glucagon luteinizing hormone-releasing hormone, leuprorelin, calcitonin, vasopressin or active fragments thereof.

[0088] Moreover, an active element(s) may be a composition containing multiple types of active substances.

[0089] While a matrix-forming component A used with a method of the present invention is not particularly limited, it preferably contains one or more compounds having a cationic dissociable group(s).

[0090] Examples of such compounds include calcium lactate, calcium chloride, chitosan, low-molecular-weight chitosan, chitosan oligosaccharide, polylysine, polyarginine, spermine, spermidine, putrescine, lysine and arginine.

[0091] Moreover, each of these compounds may also be in a form of sodium salt, magnesium salt or calcium salt.

[0092] While a matrix-forming component B is not particularly limited as long as it is capable of binding to the matrix-forming component A, it preferably contains a compound having an anionic dissociable group(s).

[0093] Examples of such compounds include inositol-6-phosphate, citric acid, alginic acid, low-molecular-weight alginic acid, hyaluronic acid, pectin, carboxymethyl cellulose, carrageenan, aspartic acid, glutamic acid, deoxyribonucleic acid, oligodeoxynucleotide, deoxynucleotide, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid and polyaspartic acid, polylactic acid, polyglutamic acid, malic acid, tartaric acid and succinic acid.

[0094] Moreover, each of these compounds may also be in a form of sodium salt, magnesium salt or calcium salt.

[0095] A combination and mixed amounts of the matrix-forming components A and B can appropriately be determined by those skilled in the art according to the required particle size of the microparticles and the type of the active element.

[0096] Hereinafter, combinations of matrix-forming components A and B will be exemplified, although the present invention is not limited thereto.

[0097] When chitosan is contained as a component of a matrix-forming component A, a matrix-forming component B would contain a compound(s) having an anionic dissociable group(s) in the molecule, and the matrix-forming component B preferably contains, as a component, at least one selected from the group consisting of inositol-6-phosphate, citric acid, alginic acid, low-molecular-weight alginic acid, hyaluronic acid, pectin, carboxymethyl cellulose, carrageenan, aspartic acid, glutamic acid, deoxyribonucleic acid, oligodeoxynucleotide, deoxynucleotide, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, polyaspartic acid, polylactic acid, polyglutamic acid, malic acid, tartaric acid and succinic acid, as well as sodium salt, magnesium salt and calcium salt of these compounds.

[0098] When polylysine is contained as a component of a matrix-forming component A, a matrix-forming component B would contain a compound(s) having an anionic dissociable group(s) in the molecule, and the matrix-forming component B preferably contains, as a component, at least one selected from the group consisting of inositol-6-phosphate, citric acid, alginic acid, low-molecular-weight alginic acid, hyaluronic acid, pectin, carboxymethyl cellulose, carrageenan, aspartic acid, glutamic acid, deoxyribonucleic acid, oligodeoxynucleotide, deoxynucleotide, pyrophosphoric acid, tripolyphosphoric acid, metaphosphoric acid, polyaspartic acid, polylactic acid, polyglutamic acid, malic acid, tartaric acid and succinic acid, as well as sodium salt, magnesium salt and calcium salt of these compounds.

[0099] When alginic acid is contained as a component of a matrix-forming component B, a matrix-forming component A would contain a compound(s) having a cationic dissociable group(s) in the molecule, and the matrix-forming component A preferably contains, as a component, at least one selected from the group consisting of calcium lactate, calcium chloride, chitosan, low-molecular-weight chitosan, chitosan oligosaccharide, polylysine, polyarginine, spermine, spermidine, putrescine, lysine and arginine.

[0100] When pectin is contained as a component of a matrix-forming component B, a matrix-forming component A would contain a compound(s) having a cationic dissociable group(s) in the molecule, and the matrix-forming component A preferably contains, as a component, at least one selected from the group consisting of chitosan, low-molecular-weight chitosan, chitosan oligosaccharide, polylysine, polyarginine, spermine, spermidine, putrescine, lysine and arginine.

[0101] The matrix-forming components A and B may each have one type of compound as the component, or may have a mixture of several compounds as the components. For example, a matrix-forming component A may contain chitosan and calcium lactate while a matrix-forming component B may contain sodium alginate and inositol-6-phosphate so that the matrix-forming components A and B will have a combination of each two components.

[0102] Alternatively, matrix-forming components A and B may have a combination of one plus multiple components. An exemplary case of such a combination may include a case where a matrix-forming component A contains chitosan as a component while a matrix-forming component B contains sodium alginate, inositol-6-phosphate and oligodeoxynucleotide.

[0103] Moreover, each of the matrix-forming components may contain similar compounds with different molecular weights. Exemplary cases include a case where a matrix-forming component A contains calcium lactate while a matrix-forming component B contains alginic acid and a low-molecular-weight alginic acid, and a case where a matrix-forming component A contains chitosan and a low-molecular-weight chitosan while a matrix-forming component B contains inositol-6-phosphate.

[0104] The mixed ratio of the matrix-forming components A and B (the ratio of the whole mixture if the matrix-forming component is a mixture) may be, for example, within a range of 1:1000 to 100:1 at a molar ratio, preferably 1:100 to 10:1 at the total molar ratio of the dissociable group(s) of each of the matrix-forming components A and B, and most preferably 1:10 to 5:1 at the total molar ratio of the dissociable group(s).

[0105] A solvent that is used when an active element, a matrix-forming component A and a matrix-forming component B are contained in solutions is not particularly limited as long as it does not denature or deactivate the active element, and may be either an aqueous solvent or an organic solvent. Examples of preferable solvents include water, acetic acid, ethanol and a mixed solution containing them in arbitrary proportions.

[0106] When an active element is contained in a solution, a concentration thereof is 0.01-50% (w/v), 0.01-50% (w/v), 0.1-50% (w/v), 0.5-50% (w/v), 1.0-50% (w/v), 2.0-50% (w/v) 3.0-50% (w/v), 4.0-50% (w/v), 5.0-50% (w/v), 6.0-50% (w/v), 7.0-50% (w/v), 8.0-50% (w/v), 9.0-50% (w/v) or 10-50% (w/v).

[0107] When a matrix-forming component A is contained in a solution, a concentration thereof is 0.01-50% (w/v), 0.1-45% (w/v) or 0.5-40% (w/v).

[0108] When a matrix-forming component B is contained in a solution, a concentration thereof is 0.01-50% (w/v), 0.1-45% (w/v) or 0.5-40% (w/v).

[0109] When producing microparticles of the present invention, in addition to an active element(s), a matrix-forming component A and a matrix-forming component B, an additive such as a stabilizer may also be added. Examples of additives include amino acids (for example, arginine, lysine, phenylalanine, etc.), glucose, sorbitol, glycerol, mannitol, sodium phosphate, propylene glycol, dextran (for example 18-82kD), polyvinylpyrrolidone (PVP), heparin, gelatin (types A and B), hydroxyethylated starch (HES), dextran sulfate, polyphosphoric acid, polyglutamic acid, polyaspartic acid, polylactic acid, konjac, glucomannan, pullulan, gelatin, shellac, zein, pectin, carboxymethyl cellulose, methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, water-soluble soybean polysaccharides, guar gum, xanthan gum, tamarind gum, carrageenan, Eudragit (registered trademark), Carbopol (registered trademark) and hydroxyethyl methacrylate. These additives may be added by being sprayed simultaneously with the active element(s) and the matrix-forming components A and B, or added to a solution containing the active element or the matrix-forming component A or B prior to spraying.

[0110] 2. Microparticles and Uses Thereof

[0111] The microparticles of the present invention are characterized in that they contain at least an active element, a matrix-forming component A and a matrix-forming component B, and in that their average particle size is 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less or 10 μm or less.

[0112] The active element(s) and the matrix-forming components A and B have already been described above. The microparticles may also contain additives in addition to the active element(s) and the matrix-forming components A and B. Additives have also been described above.

[0113] The microparticles of the present invention can be used for various purposes according to the type of the active element.

[0114] For example, the microparticles of the present invention may be used as medicine, or as a food additive or a feedstuff additive.

[0115] In the case where the microparticles of the present invention are used as medicine, other components (such as a carrier or an excipient) may be added to microparticles so as to give a form of a pharmaceutical composition (hereinafter, referred to as a “pharmaceutical composition of the present invention”).

[0116] A form of administration of a pharmaceutical composition of the present invention is not particularly limited as long as the form of administration is pharmaceutically acceptable, which may be selected according to the treatment procedure. Preferably, it is oral administration, sublingual administration, nasal administration, pulmonary administration, gastrointestinal administration, transdermal administration, ophthalmic administration, intravenous injection, subcutaneous injection, intramuscular injection, intraperitoneal injection, local injection, surgical implantation or the like, where oral administration is particularly preferable.

[0117] A pharmaceutical composition of the present invention may be a solid form such as granules, a capsule, a tablet or powder, a liquid agent such as a solution, a suspension or an emulsion, or a semiliquid preparation such as ointment, cream or paste. Alternatively, it may be an inhaler, an adhesive patch, a spray agent, a topical agent or medicated toothpaste.

[0118] Besides the microparticles of the present invention and the above-described carrier, the pharmaceutical composition of the present invention may optionally be added with other pharmaceutically acceptable components. Examples of other pharmacologically acceptable components include, but not limited to, excipients, binders, disintegrants, antioxidants, preservatives, adjuvants, lubricants, sweeteners and aroma chemicals. Examples of other pharmaceutically acceptable components include emulsified adjuvants (for example, fatty acids with carbon numbers of 6-22 and pharmaceutically acceptable salts thereof, albumin, dextran), stabilizing agents (for example, cholesterol, phosphatidic acid), tonicity agents (for example, sodium chloride, glucose, maltose, lactose, sucrose, trehalose) and pH adjusters (for example, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, sodium hydroxide, potassium hydroxide, triethanolamine). One or more types of them can be used. The content of such an additive(s) in a composition of the present invention is suitably 90% by weight or less, preferably 70% by weight or less, and more preferably 50% by weight or less.

[0119] A pharmaceutical composition of the present invention can be prepared by adding the microparticles of the present invention to a dispersion of the carrier and then appropriately stirring. The additives may be added in a suitable step before or after the addition of the microparticles of the present invention. An aqueous solvent that can be used upon preparing a pharmaceutical composition of the present invention is not particularly limited as long as it is pharmaceutically acceptable, and examples include electrolyte fluids such as injectable water, injectable distilled water and physiological saline, and carbohydrate solutions such as dextrose solution and maltose solution. Conditions such as pH and temperature in this case may appropriately be selected by those skilled in the art.

[0120] The composition of the present invention may be, for example, a liquid agent or a lyophilized preparation thereof. The lyophilized preparation can be prepared by lyophilizing the microparticles that are in a form of a liquid agent according to a common method. For example, a composition of the present invention in a form of a liquid agent can be lyophilized with the steps of performing suitable sterilization and dispensing a predetermined amount of it in a vial bottle, which is subjected to pre-freezing under the condition of about −40 to −20° C. for around 2 hours, subjected to primary drying at about 0-10° C. under reduced pressure, and subsequently subjected to secondary drying at about 15-25° C. under reduced pressure. In general, air inside the vial is replaced with nitrogen gas and the vial is capped, thereby obtaining a lyophilized preparation of the composition of the present invention.

[0121] The lyophilized preparation of the composition of the present invention can be used by resolving it by adding any suitable solution (resolving solution). Examples of such resolving solutions include injectable water, physiological saline and other general infusion solutions. Although the volume of this resolving solution differs depending on the use and is not particularly limited, a volume that is 0.5-2 times the volume of the solution before lyophilization or 500 ml or less is suitable.

[0122] With respect to a dosage of the pharmaceutical composition of the present invention, it is preferably prepared considering the type of the microparticles of the present invention contained, the dosage form, the conditions of the patient such as age and weight, the route of administration, and the nature and severity of the disease. Generally, the daily amount of the active element(s) in the microparticles of the present invention is in a range of 0.1 mg-20 g/human for an adult, and preferably in a range of 1 mg-1 g. These values may also differ depending on the type of the active element(s), the type of the target disease, the form of administration and the target molecule. Accordingly, a dose less than these values may be sufficient in some cases while a required dose, to the contrary, may be greater than these values in some cases.

[0123] For example, when microparticles having bovine lactoferrin or human lactoferrin as an active element are orally administered to an adult with a weight of 60 kg, it may be administered 1-4 times, preferably 1-2 times a day with the dosage at each time being 0.1-500 mg, and preferably 1-300 mg.

[0124] In addition, the microparticles of the present invention exhibit an excellent enteric property. In particular, components that are absorbed from the intestine such as lactoferrin are expected to give higher effect if they are delivered to the intestine without being degraded by the gastric acid. Therefore, the microparticles of the present invention are useful for preparing a medicine that contains, as an active element(s), a substance(s) that acts in the intestine or a substance(s) that acts after being absorbed from the intestine.

[0125] Other than medicine, the microparticles of the present invention can also be used as a raw material or an additive for supplements, cosmetics, food and feedstuff. When they are used as a raw material or an additive, the particles and other materials may directly be mixed together or may be mixed after a heat sterilization treatment.

[0126] For example, when microparticles having bovine lactoferrin as an active element are used as a raw material for medicine, supplements or food, they can bring about an effect such as an antibacterial effect, an antiviral effect, immune enhancement, protection against infection, an anticancer effect, blood-pressure regulation, an opioid-like effect, improvement in insomnia, an anti-anxiety effect, improvement in cognitive symptoms, improvement in memory impairment, improvement in lipid metabolism, antioxidation, anti-aging, an anti-inflammatory effect, stimulation of iron absorption, improvement in dry eye and pain relief. When used as feedstuff, the microparticles can bring about, in addition to the above-mentioned effects as a raw material for medicine, supplements and food, effects such as growth promotion, development promotion, improvement in yield, improvement in meat quality, improvement in taste, improvement in flavor and improvement in color tone.

[0127] Examples of forms of supplements include granules, tablets, capsules, an adhesive patch, powder and liquid agents.

[0128] Examples of cosmetics include a spraying agent, a cream agent, a powder agent, a mask agent, an adhesive patch, emulsion, skin lotion, soap, shampoo, body shampoo, toothpaste and cleanser.

[0129] Examples of food include pudding, jelly, konjac jelly, cream, cream portion, butter, fat and oil, spice, fluid diet, solid nutritious food, cold beverage, alcoholic beverage, sports-drink, mineral water, drinking water, energy drink, milk beverage, modified milk for infant, modified powdered milk for infant, creaming powder, fermented milk, fruit juice, vegetable juice, carbonated drink, yogurt, mayonnaise, dressing, tomato ketchup, seasoning, vinegar, sauce, soy sauce, sweet sake, sweet sake-like seasoning, ice cream, ice cream mix, whippy ice cream mix, whipped cream, ices, shaved ice, shaved ice syrup, gelato, frozen yogurt, caramel, candy, gummi candy, biscuit, rice cracker, rice cake, bread, bread mix, cake, doughnut, waffle, bagel, potato chips, chocolate, canned food, bottled food, minced product, processed meat, sausage, fish meat sausage, minced product, ham, jam, peanut butter, soybean curd, fermented soybean paste, konjac, konjac noodle, artificial rice, agar, dry noodle, raw noodle, semi-raw noodle, instant noodle, instant soup, retort pouch food, gelator, thickener for people with swallowing difficulty, food for people with swallowing difficulty, baby food, instant coffee, bagged tea, bagged green tea, additives for rice cooker, frozen meals, sandwich, boxed lunch, rice ball, rice seasoning, pickles, natto and margarine.

[0130] Examples of feedstuff include feed for pet animals, feed for livestock, feed for racehorses, feed for fish, feed for insects, feed for reptiles, feed for amphibians, feed for experimental animals, feed for zoo animals and feed for birds.

EXAMPLES

[0131] Hereinafter, the present invention will specifically be described by means of examples, although the scope of the present invention is not limited to these examples.

[Example 1] (Active Element is Solution; Pre-Mixing Spraying Process)

[0132] Chitosan (from Koyo Chemical) was dissolved in 1% acetic acid to prepare 667 g of 1.5% chitosan. To this solution, 333 ml of 10% bovine lactoferrin (from Morinaga Milk) was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 667 g of another spray stock solution with a final phytic acid concentration of 6%. NL-6 manufactured by Ohkawara Kakohki was equipped with RJ10-TLM1 nozzles and these two solutions were introduced into the spray tower through separate liquid feed means. Spraying was carried out at an airflow volume of 87 m.sup.3/h, an atomization air volume at the nozzle of 9 m.sup.3/h and an inlet temperature of 200° C. About 5 g of dry fine powder containing bovine lactoferrin as a physiologically active component was obtained.

[Example 2] (Active Element is Solution; Pre-Mixing Spraying Process)

[0133] Chitosan (from Koyo Chemical) was dissolved in 1% acetic acid to prepare 667 g of 0.15% chitosan. To this solution, 333 ml of 1% bovine lactoferrin (from Morinaga Milk) was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 667 g of another spray stock solution with a final phytic acid concentration of 0.6%. Spraying was carried out while other conditions were the same as those in Example 1, thereby obtaining about 1 g of dry fine powder containing bovine lactoferrin as a physiologically active component.

[Example 3] (Active Element is Solution; Pre-Mixing Spraying Process)

[0134] 10 g sodium alginate (under model number 31130-95 from Nacalai Tesque) was dissolved in 500 ml of water. To this solution, 500 ml of 4.6% bovine lactoferrin was added to prepare a spray stock solution. As another spray stock solution, 1000 ml of 2.5% calcium lactate solution was prepared. Spraying was carried out while other conditions were the same as those in Example 1, thereby obtaining about 5 g of dry fine powder containing bovine lactoferrin as a physiologically active component.

[Example 4] (Active Element is Solution; Post-Spray Mixing Process)

[0135] Chitosan (from Koyo Chemical) was dissolved in 1% acetic acid to prepare 50 ml of 1.5% chitosan. To this solution, 25 ml of 1% bovine lactoferrin (from Morinaga Milk) was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 75 g of another spray stock solution with a final phytic acid concentration of 6%. B-290 manufactured by Nihon Buchi was equipped with three-fluid nozzles, and these two solutions were introduced into the spray tower through separate liquid feed means. Spraying was carried out under the conditions where an inlet temperature was 150° C. About 1 g of dry fine powder containing bovine lactoferrin as a physiologically active component was obtained.

[Example 5] (Active Element is Solution; Post-Spray Mixing Process)

[0136] 8 g sodium alginate (under model number 31130-95 from Nacalai Tesque) was dissolved in 400 ml of water. To this solution, 400 ml of 1.7% bovine lactoferrin was added to prepare a spray stock solution. As another spray stock solution, 800 ml of 2.5% calcium lactate solution was prepared. MDL-050M from Fujisaki Electric was equipped with four-fluid straight edge nozzles SE4003, and these two solutions were introduced into the spray tower at a speed of 15 ml/min. through separate liquid feed means. Spray drying was carried out at an inlet temperature of 200° C., an air-intake volume of 1 m.sup.3/min. and nozzle air of 45 NL/min. About 10 g of dry fine powder containing bovine lactoferrin as a physiologically active component was obtained.

[Example 6] (Active Element is Solution; Post-Spray Mixing Process)

[0137] 8 g sodium alginate (under model number 31130-95 from Nacalai Tesque) was dissolved in 400 ml of water. To this solution, 500 g of phytic acid with a final concentration of 6% and 100 ml of 10% bovine lactoferrin were dissolved to prepare about 1000 ml of a spray drying stock solution. 1000 ml of another spray stock solution of 2.5% calcium lactate solution and 1.5% chitosan was prepared. MDL-050M from Fujisaki Electric was equipped with four-fluid straight edge nozzles SE4003, and these two solutions were introduced into the spray tower at a speed of 15 ml/min. through separate liquid feed means. Spraying was carried out while other conditions were the same as those in Example 4, thereby obtaining about 10 g of dry fine powder containing bovine lactoferrin as a physiologically active component.

[Example 7] (Active Element is Solution; Post-Spray Mixing Process)

[0138] To 4 L of 5% chitosan solution, 2 L of 10% bovine lactoferrin was added to prepare about 6 L of a spray drying stock solution. 6 L of 4% phytic acid was prepared. MDL-050M from Fujisaki Electric was equipped with four-fluid straight edge nozzles SE4003, and these two solutions were introduced into the spray tower at a speed of 15 ml/min. through separate liquid feed means. Spraying was carried out while other conditions were the same as those in Example 4, thereby obtaining about 500 g of dry fine powder containing bovine lactoferrin as a physiologically active component.

Example 8

[0139] To 200 g of dry fine powder containing bovine lactoferrin as a physiologically active component produced according to the same method as Example 6, 456 g of lactose, 160 g of crystalline cellulose (trade name: Avicel), 16 g of carboxymethyl cellulose/calcium salt and 8 g of sucrose fatty acid ester were added. The resulting mixture was pulverized with a mixer so as to obtain powder that passes through 100 mesh. This mixed powder was subjected to tableting using a tableting machine to produce tablets.

Example 9

[0140] To 200 g of dry fine powder containing bovine lactoferrin as a physiologically active component produced according to the same method as Example 6, 50 g of water and 50 g of ethanol were added. The resultant was kneaded in a mortar, then transferred into a stainless-steel kitchen strainer and pushed in with a pestle. The resulting particles were air dried to produce about 150 g of granules.

Example 10

[0141] 200 g of dry fine powder containing bovine lactoferrin as a physiologically active component produced according to the same method as Example 6, was mixed with 1 kg of condensed milk whey powder to produce 1.2 kg of a whey protein-based muscle-building nutritional supplement.

[Example 11] (Active Element is Solution; Post-Spray Mixing Process)

[0142] To 25 ml of 1% bovine lactoferrin (from Morinaga Milk), porcine pepsin (from Sigma-Aldrich) was added to obtain a final concentration of 0.02%. The resultant was heated at 37° C. for 2 hours and then at 68° C. for 30 minutes. To this suspension, 50 ml of 1.5% chitosan (from Koyo Chemical) dissolved in 1% acetic acid was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 75 g of another spray stock solution with a final phytic acid concentration of 6%. B-290 manufactured by Nihon Buchi was equipped with three-fluid nozzles and these two solutions were introduced into the spray tower through separate liquid feed means. Spraying was carried out under the conditions where an inlet temperature was 150° C. About 1 g of dry fine powder containing a bovine lactoferrin-degrading peptide as a physiologically active component was obtained.

[Example 12] (Active Element is Solution; Post-Spray Mixing Process)

[0143] To 25 ml of 1% recombinant human lactoferrin (from Ventria, US), 50 ml of 1.5% chitosan (from Koyo Chemical) dissolved in 1% acetic acid was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 75 g of another spray stock solution with a final phytic acid concentration of 6%. B-290 manufactured by Nihon Buchi was equipped with three-fluid nozzles and these two solutions were introduced into the spray tower through separate liquid feed means. Spraying was carried out under the conditions where an inlet temperature was 150° C. About 1 g of dry fine powder containing recombinant human lactoferrin as a physiologically active component was obtained.

[Example 13] (Active Element is Solution; Post-Spray Mixing Process)

[0144] To 25 ml of 1% human insulin (from Sigma-Aldrich), 50 ml of 1.5% chitosan (from Koyo Chemical) dissolved in 1% acetic acid was added to prepare a spray stock solution. To 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, thereby preparing 75 g of another spray stock solution with a final phytic acid concentration of 6%. B-290 manufactured by Nihon Buchi was equipped with three-fluid nozzles and these two solutions were introduced into the spray tower through separate liquid feed means. Spraying was carried out under the conditions where an inlet temperature was 150° C. About 1 g of dry fine powder containing human insulin as a physiologically active component was obtained.

Test Example 1

[0145] Macroparticles were produced by a conventional method in order to compare their properties with those of the microparticles of the present invention. Macroparticles containing insulin as a physiologically active component were produced following Bio-Medical Materials 21 25-36 2011. Specifically, 3% insulin was dispersed in 3% chitosan dissolved in 1% acetic acid solution to give Stock solution 1. Stock solution 1 was introduced into a syringe equipped with a needle with a diameter of 0.241 mm, and dropped as droplets into a 6% phytic acid solution (pH 6, 25° C.) while slowly stirring with a magnetic stirrer. The macroparticles were washed with water and then subjected to lyophilization.

Test Example 2

[0146] This method is a test carried out for examining elution characteristics of the microparticles or the macroparticles in vitro. Following Bio-Medical Materials 21 25-36 2011, a simulated gastric fluid and a simulated intestinal fluid were prepared. Specifically, the simulated gastric fluid was obtained by dissolving 2 g of sodium chloride and 7 ml of 35% hydrochloric acid and adjusting the resultant to be 1 L with distilled water. The simulated intestinal fluid was obtained by dissolving 250 ml of 0.2M KH.sub.2PO.sub.4 and 118 ml of 0.2N NaOH and adjusting the resultant to be 1 L (pH6.8). The particles to be assessed were incubated with the simulated gastric fluid at 37° C. for 2 hours while rotating at 80 rpm, and then with the simulated intestinal fluid at 37° C. for another 2 hours or longer. The drug eluted into each of the simulated solutions was allowed to pass through a 0.45 μm filter and applied to reversed-phase HPLC for an analysis.

[0147] The microparticles of Example 4 and the macroparticles produced in Test Example 1 were used to examine the elution characteristics. The results are shown in FIG. 1. With respect to the conventional macroparticles produced in Test Example 1, more than half of the insulin has eluted in the simulated gastric fluid and scarcely eluted in the subsequent simulated intestinal fluid. Specifically, suppression of the release of the encapsulated insulin was insufficient under an acidic condition corresponding to the gastric fluid. On the other hand, with respect to the microparticles of Example 4 of the present invention, the encapsulated lactoferrin was scarcely eluted in the simulated gastric fluid and mostly eluted in the subsequent simulated intestinal fluid. Accordingly, the conventional macroparticles and the microparticles of the present invention showed completely different eluting properties. The microparticles of the present invention were found to show higher stability in the stomach. The microparticles and food of Examples 1-14 were also analyzed and they gave almost same results.

[0148] FIG. 1 shows the results from the eluting tests of the microparticles of Example 4 and Test Example 1. In FIG. 1, the horizontal axis represents eluting time (min), the vertical axis represents eluting rate (%), the dashed line represents eluting of the microparticles of the present invention, and the solid line represents eluting of the macroparticles of the conventional method.

Test Example 3

[0149] The particle size distributions of the microparticles of Example 4 and the macroparticles produced in Test Example 1 were examined by a laser diffraction/scattering particle size distribution measurement. The results are shown in FIGS. 2 and 3.

[0150] In FIG. 2, the horizontal axis represents particle size (μm), the vertical axis represents frequency (%), and the black line represents the particle size distribution of the microparticles of the present invention.

[0151] In FIG. 3, the horizontal axis represents particle size (μm), the vertical axis represents frequency (%), and the black line represents the particle size distribution of the macroparticles produced by the conventional method.

[0152] While the average particle size of the microparticles of the present invention was 8 μm with the largest particle size being 100 μm or less, the average particle size of the macroparticles according to the conventional method was several-hundreds of μm with the largest particle size being at least 1,000 μm. An average particle size as used herein refers to a particle size at an integrated value of 50% of the equivalent sphere diameters obtained by the laser diffraction/scattering particle size distribution measurement.

Test Example 4

[0153] Improvements in stability of the physiologically active substances in the body after administering the particles into animals, absorption into the body, and delivery into the body were examined.

[0154] A lactoferrin control or the microparticles produced in Example 6 dissolved or suspended in 100 mM HCl were administered to 10-week-old fasted rats F344 using a gastric tube. The dosage was 50 mg lactoferrin per kilogram of rat weight. The contents from the small intestines were recovered after 30 minutes administration. The recovered small intestinal contents were two-fold diluted with an SDS-PAGE sample buffer. The supernatants were subjected to heat denaturation followed by SDS-PAGE.

[0155] The results from the electrophoresis are shown in FIG. 4. Lane 1 shows migration of the small intestinal contents from the rat administered the microparticulated lactoferrin. Lane 2 shows migration of the small intestinal contents from the rat administered the lactoferrin control. The figures show the size of the molecular weight markers, and the arrow shows the location of the intact lactoferrin.

[0156] As shown in FIG. 4, intact lactoferrin was observed only in the case where the microparticulated lactoferrin was administered. The microparticles were found to improve stability of the physiologically active substances in the body after administration into animals, absorption into the body, and delivery into the body.

[Example 14] (Active Element is Suspension; Pre-Spray Mixing Process)

[0157] To 50% phytic acid solution (from Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, and the resultant was diluted with water to prepare 100 ml of 12% phytic acid solution. This solution was mixed with 100 ml of 100% ethanol (from Wako Pure Chemical Industries) to give Stock solution 1. A solution was prepared by dissolving bovine lactoferrin into 1000 ml of 125 mM NaCl to a final concentration of 1%. To this solution, 1000 ml of ethanol was added at once, which was vigorously stirred to prepare a lactoferrin suspension. The suspension was centrifuged at 6000 g. The precipitation was collected and resuspended in the previously added Stock solution 1 to prepare a spray stock solution. Chitosan (from Yaizu Suisankagaku Industry) was dissolved in 1% acetic acid to prepare 200 ml of 1.5% chitosan spray stock solution. NL-6 manufactured by Ohkawara Kakohki was equipped with RJ10-TLM1 nozzles and these two solutions were introduced into the spray tower through separate liquid feed means. The suspension was stirred with a magnetic stirrer so that no sediment was formed in the spray. Spraying was carried out at an airflow volume of 84 m.sup.3/h, an atomization air volume at the nozzle of 8 m.sup.3/h and an inlet temperature of 200° C. About 8 g of dry fine powder containing bovine lactoferrin as a physiologically active component was obtained.

[Example 15] (Active Element is Suspension; Post-Spray Mixing Process)

[0158] To a 50% phytic acid solution (Tsuno Food Industrial Co., Ltd.), sodium hydroxide was added to adjust pH to 6, and the resultant was diluted with water to prepare 100 ml of 12% phytic acid solution. This solution was mixed with 100 ml of 100% ethanol (from Wako Pure Chemical Industries) to give Stock solution 1. A solution was prepared by dissolving bovine lactoferrin into 1000 ml of 125 mM NaCl to a final concentration of 1%. To this solution, 1000 ml of ethanol was added at once, which was vigorously stirred to prepare a lactoferrin suspension. The suspension was centrifuged at 6000 g. The precipitation was collected and resuspended in the previously added Stock solution 1 to prepare a spray stock solution. Chitosan (from Yaizu Suisankagaku Industry) was dissolved in 1% acetic acid to prepare 200 ml of 1.5% chitosan spray stock solution. MDL-050M manufactured by Fujisaki Electric was equipped with four-fluid straight edge nozzles SE4003 and these two solutions were introduced into the spray tower at a speed of 10 ml/min. through separate liquid feed means. Spray drying was performed at an inlet temperature of 150° C., an air-intake volume of 1 m.sup.3/min., and nozzle air of 45 NL/min. The suspension was stirred with a magnetic stirrer so that no sediment was formed in the spray. About 12 g of dry fine powder containing bovine lactoferrin as a physiologically active component was obtained.

Test Example 5

[0159] The particle size distribution of the microparticles of Example 15 was examined by a laser diffraction/scattering particle size distribution measurement. The results are shown in FIG. 5. In FIG. 5, the horizontal axis represents particle size (μm), the vertical axis represents frequency (%), and the black line represents the particle size distribution. The average particle size of the microparticles of Example 15 was 48 μm. Although the particle size of the microparticles of Example 15 was larger than the average particle size (8 μm) of the microparticles produced in Example 4 and analyzed in Test Example 3, the average particle size was 48 μm which was still 100 μm or less, where particles of less than 100 μm made up 89% of the entire particles. Specifically, most of the particles obtained in Example 15 had particle sizes of 100 μm or less. The microparticles of Example 14 were also analyzed and gave almost same results. An average particle size as used herein refers to a particle size at an integrated value of 50% of the equivalent sphere diameters obtained by the laser diffraction/scattering particle size distribution measurement.

INDUSTRIAL APPLICABILITY

[0160] According to the method of the present invention, microparticles having an average particle size of 100 μm or less can be produced in a simple and inexpensive manner. In addition, the microparticles having an average particle size of 100 μm or less produced by the described methods can be used to produce novel medicine, feedstuff or food.