Janus microparticles and methods for producing the same

Abstract

The present invention addresses the problem of providing: Janus fine particles that enable the very efficient impregnation of aqueous drug solutions / suspensions at high contents in only a porous hemisphere side; and a method for producing the Janus fine particles. The present invention provides Janus fine particles constituted of a porous hemisphere section and a nonporous hemisphere section, and having a particle diameter of 0.01-5,000 µm. The porous hemisphere section has a better water wettability than the nonporous hemisphere section.

Description

[Technical Field]

[0001] This invention relates to heteromorphic microparticles (Janus microparticles) composed of two or more different substances, and a method for producing the same. [Background technology]

[0002] Janus microparticles (heteromorphic microparticles), in which one hemisphere is composed of substance A and the other hemisphere is composed of substance B which is different from substance A, have attracted rapidly increasing attention in recent years due to their diverse applications (Non-Patent Literature 1 to 4). Examples of Janus microparticle applications include substitutes for surfactants (Non-Patent Literature 5), elementary particles for displays (Non-Patent Literature 6), and magnetic therapy for cancer (Non-Patent Literature 7). Methods for preparing Janus microparticles have been reported, including methods using multifluid nozzles and methods utilizing phase separation between polymers (Non-Patent Literature 8 to 10). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Perec V et al., Science 315,1393 (2007) [Non-Patent Document 2] Chen Q et al., Science 331, 199 (2011) [Non-Patent Document 3] Reynwaw BJ et al., Nature 447, 461 (2007) [Non-Patent Document 4] Sacanna S et al., Nature 464, 575 (2010) [Non-Patent Document 5] Ruhland T et al., Langmuir 27, 9807 (2011) [Non-Patent Document 6] Yin SN et al., Adv.Matter. 23, 2915 (2011) [Non-Patent Document 7] Hu SH et al., J.Am.Chem.Soc. 132, 7234 (2010) [Non-Patent Document 8] Takasi Nisisako et al., Adv.Mater. 2006, 18, 1152-1156 [Non-Patent Document 9] Zhihong Nie et al., J.Am.Chem.SOC. 2006, 128, 9408-9412 [Non-Patent Document 10] Chariya. Kaewsaneha et al., ACS Appl. Mater. Interfaces, 2013, 5 (6), 1857-1869 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The problem to be addressed by this invention is to provide Janus microparticles and a method for producing the same, which can efficiently impregnate only the porous hemisphere with a drug aqueous solution / suspension at a high content. [Means for solving the problem]

[0005] As a result of diligent research to solve the above problems, the inventors of the present invention have found that by constructing Janus microparticles from a porous hemispherical portion and a non-porous hemispherical portion, and by adopting a configuration in which the porous hemispherical portion has good wetting properties and the non-porous hemispherical portion has poor wetting properties, it is possible to efficiently impregnate only the porous hemisphere with a high concentration of the drug aqueous solution / suspension, thus completing the present invention.

[0006] In other words, the present invention provides the following invention. <1> Janus microparticles having a particle size of 0.01 to 5000 μm, comprising a porous hemispherical portion and a non-porous hemispherical portion, wherein the wetting of the porous hemispherical portion with water is better than that of the non-porous hemispherical portion. <2> At least the non-porous hemispherical portion of the Janus microparticles further contains wax, <1> Janus microparticles as described above. <3> The porous hemispherical portion contains at least a polymer that swells upon water absorption. <1> or <2> Janus microparticles as described above. <4> The porous hemisphere contains at least an enteric-coated polymer. <1> from <3> Janus particles as described in any one of the following. <5> The porous hemisphere contains at least hypromellose phthalate or hydroxymethylcellulose succinate acetate. <1> from <4> Janus particles as described in any one of the following. <6> The porous hemispherical portion contains the drug. <1> from <5> Janus particles as described in any one of the following. <7> The drug is a peptide, protein, nucleic acid, or nucleic acid derivative. <6> Janus microparticles as described above. <8> The porous hemispherical portion contains absorption enhancers, protease inhibitors, mucosal adhesion polymers, and sol-gel agents. <1> from <5> Janus particles as described in any one of the following items. <9> The following steps (i) and (ii) are included: <1> from <7> A method for producing Janus microparticles as described in any one of the following. (i) A step of emulsifying a solution obtained by dissolving one or more substances that wet well and one or more substances that wet poorly in a common solvent in an aqueous solution containing a surfactant; and (ii) A step of drying the emulsion to remove the solvent. <10> The volume of the surfactant-containing aqueous solution is 0.5 to 10 times the volume of the solution in which one or more substances with good wetting properties and one or more substances with poor wetting properties are dissolved in a common solvent. <8> Methods used. <11> In step (ii), the emulsion is dried for 30 minutes or more to remove the solvent. <8> or <9> Methods used. <12> After step (ii), (iii) A step of impregnating a porous hemisphere with an aqueous solution or suspension of a drug, Further including, <8> from <10> The method described in any one of the following. <13> The method according to any one of <8> to <11>, wherein the surfactant is a nonionic surfactant. <14> The method according to any one of <8> to <12>, wherein the surfactant is polyvinyl alcohol.

Advantages of the Invention

[0007] According to the Janus microparticles and the method for producing the same of the present invention, a formulation for efficiently promoting the absorption of a drug into a biological membrane can be provided.

Brief Description of the Drawings

[0008] [[ID=|16]] [Figure 1] Figure 1 shows an overview of the system of the present invention. [Figure 2] Figure 2 shows the Janus microparticles in Example 1. [Figure 3] Figure 3 shows the Janus microparticles in Example 1. [Figure 4] Figure 4 shows the Janus microparticles in Example 1. [Figure 5] Figure 5 shows the Janus microparticles in Comparative Example 1. [Figure 6] Figure 6 shows the Janus microparticles in Example 2. [Figure 7] Figure 7 shows the Janus microparticles in Example 3. [Figure 8] Figure 8 shows the Janus microparticles in Example 4. [Figure 9] Figure 9 shows the Janus microparticles in Example 5. [Figure 10] Figure 10 shows the Janus microparticles in Example 6. [Figure 11] Figure 11 shows the Janus microparticles in Example 7. [Figure 12] Figure 12 shows the Janus microparticles in Example 8. [Figure 13] Figure 13 shows the change in plasma glucose concentration after administration of each formulation.

Modes for Carrying Out the Invention

[0009] The present invention will be described in more detail below. The Janus microparticles of the present invention are Janus microparticles with a particle size of 0.01 to 5000 μm, composed of a porous hemispherical portion and a non-porous hemispherical portion. In the Janus microparticles of the present invention, the wetting of the porous hemispherical portion with water is better than that of the non-porous hemispherical portion.

[0010] The enhancement of drug absorption in biological membranes has been studied for a long time, with various methods being proposed, including the use of absorption enhancers, co-administration of enzyme inhibitors, and the use of mucosal adhesion polymers. The use of microparticles is one such technology. It is believed that by releasing drugs near the absorption surface of the biological membrane using microparticles, enzymatic degradation of the drug can be suppressed, and the amount of drug absorbed through the membrane can be increased. However, there is no selectivity in the direction of drug release from microparticles; some drugs are released toward the absorption surface, while others are released toward the opposite side. Furthermore, the released drugs are subjected to degradation on their way to the absorption surface. Takada et al. have proposed hemispherical formulations that suppress drug release from the spherical surface and limit it to drug release from the planar surface. The planar portion of the drug release surface adheres to the absorption surface of the biological membrane, while the spherical portion suppresses drug release toward the opposite side of the biological membrane and acts as a barrier to enzymes, thereby efficiently facilitating drug absorption into the biological membrane. However, manufacturing fine hemispherical formulations is technically challenging.

[0011] In this invention, we have devised a system shown in Figure 1 by utilizing the characteristics of Janus microparticles. One hemisphere suppresses drug release to the opposite side of the biological membrane and acts as a barrier against enzymes, while the other hemisphere melts at a temperature close to body temperature and is absorbed upon contact with the biological membrane. In this case, it is necessary to distribute the drug at a high concentration on the mucous membrane side. As a method for encapsulating the drug in microparticles, one can be considered to dissolve a microparticle base in a solvent to produce an oil phase, emulsify it in a small amount of aqueous phase, gradually dry it in liquid, and add a surfactant, an insoluble solid or water droplet to the oil phase to form a solid-in-oil (S / O) emulsion or a water-in-oil (W / O) emulsion. However, with this method, it is difficult to encapsulate more than 30% of the drug. Therefore, as a result of creative research, we succeeded in producing Janus microparticles consisting of a hemisphere with good wetting properties and a substance with poor wetting properties, and producing microparticles in which the hemisphere made of the substance with good wetting properties is porous. Furthermore, we conceived the idea that by adding wax such as hard fat to poorly wettable hemispheres to further worsen wetting, and then adding a drug-containing solution, it is possible to efficiently impregnate the well-wettable and porous hemispheres. In addition, poor wetting of non-porous hemispheres is also effective in the manufacturing of the fine particles. Specifically, by poor wetting of non-porous hemispheres, the aqueous solution used during manufacturing (aqueous phase of the emulsion and aqueous solution dried in liquid) becomes less likely to penetrate the non-porous hemispheres, and as a result, pore formation is further inhibited in the non-porous hemispheres.

[0012] Wetting is the phenomenon in which the interface between a solid and a gas is replaced by the interface between a solid and a liquid. When a liquid is dropped onto a solid surface, if the liquid comes to rest and contacts the solid surface at an angle θ, θ is called the contact angle and is used as a value to evaluate wettability (Noguchi, Osamu, ed., General Theory of Pharmaceutical Pharmaceutics and Physical Pharmaceutics, Kyoto Hirokawa Shoten, pp. 18). A larger contact angle results in poor wetting. In order for a drug-containing solution to efficiently impregnate a porous hemisphere, it is desirable to make the contact angle between the solution and the non-porous hemisphere composition larger than the contact angle between the solution and the porous hemisphere composition. Alternatively, the contact angle between water and each hemisphere composition may be used for simplicity. The difference between the contact angle between water and the porous hemisphere composition and the contact angle between water and the non-porous hemisphere composition should be 5° or more, preferably 10° or more, more preferably 20° or more, and even more preferably 30° or more.

[0013] The method for measuring the contact angle is not particularly limited and can be any general method such as the drop method, capillary method, or moist heat measurement method. For a simple evaluation, it is preferable to prepare films with the composition of each hemisphere, drop the solution onto them, and determine the contact angle using the drop method.

[0014] The particle size of the Janus microparticles can be 0.01 to 5000 μm, but is preferably 0.05 to 500 μm, and more preferably 0.1 to 100 μm.

[0015] The porous hemispherical portion preferably contains a polymer that swells upon water absorption, such as an enteric-coated polymer.

[0016] Examples of materials for the porous hemispherical portion include hypromellose phthalate or hydroxymethylcellulose succinate acetate, but are not particularly limited.

[0017] Examples of materials for the non-porous hemispherical portion include polylactic acid, polyglycolic acid, lactic acid-glycolic acid copolymer, oligolactic acid, polyacrylate, polymethacrylate, acrylate-methacrylate copolymer, polycaprolactone, polyvinylpyrrolidone (PVP), and cellulose-based polymers (e.g., ethylcellulose, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose (HPC), cellulose phthalate acetate, hydroxypropyl methylcellulose phthalate). Examples of polyacrylates, polymethacrylates, and acrylate-methacrylate copolymers that can be used include ammonium acrylate copolymer (Eudragit® RL100 or RS100, or Eudragit® RL30D or RS30D), ethyl acrylate methyl methacrylate copolymer (Eudragit® NE30D), or methacrylic acid copolymer (Eudragit® L100-55, Eudragit® L30D, Eudragit® E100, Eudragit® EPO), starch polymer, chitosan, etc.

[0018] The non-porous hemispherical portion is preferably made of ethyl cellulose, but is not particularly limited.

[0019] The non-porous hemispherical portion preferably further contains wax. The type of wax is not particularly limited, but specific examples include saturated fatty acids with 14 to 24 carbon atoms (e.g., myristic acid, palmitic acid, stearic acid, behenic acid, etc.) or their salts (e.g., sodium salts, potassium salts); higher alcohols with 16 to 24 carbon atoms (e.g., cetyl alcohol, stearyl alcohol, etc.); monoglycerides, diglycerides, or triglycerides of saturated and / or unsaturated fatty acids with 8 to 24 carbon atoms; and fats and oils (e.g., castor oil, cottonseed oil, olive oil, soybean oil). Examples of lipids include oils, rapeseed oil, and hardened oils such as beef tallow; waxes (e.g., beeswax, carnauba wax, whale wax, etc.); hydrocarbons (e.g., paraffin, microcrystalline wax, etc.); cholesterol; glycolipids (e.g., sphingolipids, ceramides, etc.); phospholipids (e.g., phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, hydrogenated lecithin, etc.); and hydrophobic vitamins (e.g., vitamin E, vitamin A, vitamin D, vitamin K, etc.). As lipids, fatty acid triglycerides (tri-O-acylglycerol), which are esters of fatty acids and glycerol, are particularly preferred. These lipids can be used individually or in appropriate combinations and mixtures. Furthermore, by adding lower C6-C12 lipids (e.g., fatty acids such as capric acid and lauric acid, their salts, esters, alcohols, or glycolipids, phospholipids, etc.) or low-melting-point lipids such as vegetable oils (e.g., soybean oil, olive oil, castor oil, rapeseed oil, etc.) to these lipids, the melting point, consistency, or interfacial tension of the lipid phase can be appropriately adjusted.

[0020] Preferably, waxes such as GELUCIRE and Suppocire AM can be used. Suppocire AM PASILLES is a glyceride base containing saturated C8-C18 triglyceride fatty acids, with a melting point of 35.0-36.5°C and a hydroxyl value of 5.

[0021] In this invention, the porous hemispherical portion contains a drug. Examples of drugs include peptides, proteins, nucleic acids (such as DNA, DNA decoys, DNA plasmids, aptamers, RNA, SsiRNA, tRNA, miRNA, and heteroduplex nucleic acids of DNA and RNA), or nucleic acid derivatives (including chimeric compounds of DNA and RNA and their derivatives), and peptide nucleic acids. Specific examples of peptides, proteins, nucleic acids, or nucleic acid derivatives include proteins such as growth hormone-releasing factor, growth factors, epidermal growth factor (EGF), nerve growth factor (NGF), TGF, PDGF, insulin growth factor (IGF), fibroblast growth factors (aFGF, bFGF, etc.), somatostatin, calcitonin, insulin, vasopressin, interferon, IL-2, urokinase, serrathiopeptidase, superoxide dismutase (SOD), thyrotropin, thyrotropin-releasing hormone (TRH), luteinizing hormone-releasing factor (LH-RH), corticotropin-releasing hormone (CRF), growth hormone-releasing hormone (GHRH), oxytocin, erythrotropin (EPO), and colony-stimulating factor (CSF), as well as peptides obtained from these proteins and their parts, and peptide vaccines obtained from specific antigens, which can also be used as pharmaceuticals. Furthermore, nucleic acids or nucleic acid derivatives that encode these proteins or peptides can be used.

[0022] Nucleic acid derivatives include ribonucleotides, deoxyribonucleotides, and molecules modified from RNA or DNA, and may be naturally occurring or unnatural molecules.

[0023] Examples of nucleic acid derivatives include molecules to which another chemical substance has been added to nucleic acid, such as 5'-polyamine-added derivatives, cholesterol-added derivatives, steroid-added derivatives, bile acid-added derivatives, vitamin-added derivatives, Cy5-added derivatives, Cy3-added derivatives, 6-FAM-added derivatives, and biotin-added derivatives.

[0024] Other examples of nucleic acid derivatives include, for example, oligonucleotide derivatives substituted with sugars such as 2'-O-propylribose, 2'-methoxyethoxyribose, 2'-O-methylribose, 2'-O-methoxyethylribose, 2'-O-[2-(guanidium)ethyl]ribose, or 2'-O-fluororibose. Furthermore, examples of phosphate group modifications include oligonucleotide derivatives in which the phosphate diester bond in the oligonucleotide is converted to a phosphothioate bond, and oligonucleotide derivatives in which the phosphate diester bond in the oligonucleotide is converted to an N3'-P5' phosphatemidate bond.

[0025] In addition to drugs, the porous hemispherical portion can be impregnated with absorption enhancers, protease inhibitors, mucosal adhesion polymers, sol-gel agents, and other substances.

[0026] The Janus microparticles of the present invention are produced by the following steps: (i) A step of emulsifying a solution obtained by dissolving one or more substances that wet well and one or more substances that wet poorly in a common solvent in an aqueous solution containing a surfactant; and (ii) A step of drying the emulsion to remove the solvent. It can be manufactured by [method].

[0027] After step (ii) above, (iii) A step of impregnating a porous hemisphere with an aqueous solution or suspension of a drug, You may also include the following:

[0028] The "aqueous solution or suspension of a drug," or the "solution obtained by dissolving one or more substances that wet well and one or more substances that do not wet well in a common solvent," may include substances with surfactant properties, such as amphiphilic substances like surfactants, which can promote the impregnation of the drug solution into the porous hemispheres. Furthermore, the "aqueous solution or suspension of a drug" may include substances that impart functionality to the microparticles for biological purposes, such as absorption enhancers or mucosal adhesion substances.

[0029] In step (i), a solution in which one or more substances with good wettability and one or more substances with poor wettability are dissolved in a common solvent is used. The common solvent is not particularly limited as long as it can dissolve both one or more substances with good wettability and one or more substances with poor wettability to be used. For example, methylene chloride, ethyl acetate, hexane, cyclohexane, ethanol, methanol, propanol, acetone, THF, DMF, DMSO, acetic acid, and mixed solvents of these solvents can be used.

[0030] The liquid for emulsifying the solution in which one or more substances with good wettability and one or more substances with poor wettability are dissolved in a common solvent is not particularly limited as long as it is a liquid that phase-separates from the solution in which one or more substances with good wettability and one or more substances with poor wettability are dissolved in a common solvent. For example, water, glycerin, silicone oil, castor oil, soybean oil, olive oil, etc. can be used.

[0031] The surfactant used in the present invention is not particularly limited as long as it can emulsify a solution of one or more substances with good wettability and one or more substances with poor wettability, and any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, or a nonionic surfactant may be used. As the surfactant, one surfactant may be used, or two or more different surfactants may be used in combination.

[0032] Examples of anionic surfactants include soap (sodium fatty acid) RCOO - Na + , monoalkyl sulfate ROSO3 - M + , alkyl polyoxyethylene sulfate RO(CH2CH2O) m SO3 - M + , alkylbenzene sulfonate RR'CH2CHC6H4SO3 - M + , monoalkyl phosphate ROPO(OH)O - M + and the like. Examples of cationic surfactants include alkyltrimethylammonium salts (RN) + (CH3)3X - , dialkyldimethylammonium salt RR'N + (CH3)2X - , alkylbenzyldimethylammonium salt RN + (CH2Ph)(CH3)2X - These are some examples.

[0033] Examples of amphoteric surfactants include alkyldimethylamine oxide R(CH3)2NO and alkylcarboxybetaine R(CH3)2N + CH2COO - These are some examples. Examples of nonionic surfactants include polyoxyethylene alkyl ether RO(CH2CH2O) m Examples include H, fatty acid sorbitan esters, alkyl polyglucosides, fatty acid diethanolamide RCON(CH2CH2OH)2 or alkyl monoglyceryl ether ROCH2CH(OH)CH2OH, and polyvinyl alcohol.

[0034] As the surfactant, nonionic surfactants are particularly preferred, and polyvinyl alcohol is even more preferred.

[0035] The volume of the surfactant-containing aqueous solution in step (i) described above is preferably 0.5 to 10 times, and more preferably 1 to 10 times, the volume of the solution obtained by dissolving one or more substances that wet well and one or more substances that do not wet well in a common solvent.

[0036] In step (ii), the time for removing the common solvent is not particularly limited as long as the desired Janus fine particles can be produced, but it is preferable to remove the solvent by drying the emulsion for 30 minutes or more. The time for removing the common solvent is more preferably 30 minutes to 6 hours, and even more preferably 1 to 4 hours.

[0037] In this invention, a solution obtained by dissolving one or more substances with good wetting properties and one or more substances with poor wetting properties in a common solvent, an aqueous solution of a surfactant, or an aqueous solution or suspension of a drug contains, as an additive, a mucolytic agent (e.g., L-cysteine, N-acetylcysteine), a permeation enhancer or absorption enhancer (e.g., medium-chain fatty acids, long-chain unsaturated fatty acids, their monoglycerides or their polyethylene glycol esters or mixtures of both such as labrazole, bile salts, chelating agents, glycolipids including alkyl saccharides, Azone®, Transcutol®, cyclodextrin, Claudin binders and their derivatives, etc.). This may include junction modifiers, buffers (e.g., phosphate buffers, citrate buffers, carbonate buffers, etc.), enzyme inhibitors (e.g., aprotinin, bacitracin, camostat, citric acid, tartaric acid, sodium edetate, sodium glycocholate, SUPERase·In®, RNasin®, etc.), gravity modifiers (e.g., glycerin, sucrose, glucose, amino acids, porous silica, etc.), antioxidants (e.g., ascorbic acid, hydroxybutylanisole, tocopherol, ascorbic acid, CoQ10, fullerene, fullerene derivatives, etc.), light-shielding and light-absorbing agents (titanium dioxide, oxybenzone, octocrylene, etc.), etc.

[0038] The present invention will be described in more detail by the following examples, but the present invention is not limited to these examples. [Examples]

[0039] <Example 1> A solution was prepared by dissolving 60 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 200 mg of ethylcellulose (Karacon ETHOCEL STD7), 120 mg of GELUCIRE 39 / 01 (GATTEFOSSE), and 0.1 mg of Oil Red as a dye in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol. This solution was then emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for one day. When the resulting fine particles were observed with a scanning electron microscope, it was found that they were fine particles with a diameter of approximately 20 μm, each having a spherical shape with one hemisphere being porous and the other hemisphere being non-porous (Figure 2).

[0040] These microparticles were dispersed in 0.1 M phosphate buffer (pH 8.0), washed with water, and freeze-dried. When the obtained microparticles were observed with a scanning electron microscope, the porous hemispheres dissolved, yielding hemispheres (Figure 3). From this, it is thought that the porous hemispheres are composed of alkali-soluble HP55.

[0041] The microparticles shown in Figure 2 were impregnated with an aqueous solution of fluorescent-labeled dextran (FD4) with a molecular weight of 4,000, to a 50% FD4 content. The fluorescence microscope image is shown in Figure 4. It was confirmed that FD4 was distributed only in one hemisphere. The hemisphere where FD4 was distributed is thought to be the porous hemisphere composed of HP55, which has good wettability. The absence of FD4 in the other hemisphere is thought to be a result of poor wettability due to the inclusion of hard fats such as Suppocire AM. Furthermore, it was demonstrated that the porous nature allows for high-concentration drug encapsulation by the impregnation method.

[0042] <Comparative Example 1> (Preparation of porous ethylcellulose microspheres) 2 g of ethylcellulose (Nisshin Kasei Etocell 7cps) was dissolved in 16 g of acetone (Solution A). 1 g of 5% polyvinyl alcohol (Kuraray Kuraray Poval 220C) and 7 g of glycerin were mixed and added to Solution A, and emulsified for 1 minute at 12000 rpm using a homogenizer (IKA Ultra-Turrax T18) (Solution B). 45 g of glycerin and 5 g of 5% polyvinyl alcohol aqueous solution were mixed and added to a propeller stirrer (HEIDON Three-One Motor) while stirring at 600 rpm, and emulsified for 1 minute. Immediately after emulsification, the emulsion was added to 500 mL of purified water being stirred with a propeller stirrer (HEIDON Three-One Motor) at 400 rpm, and porous microspheres (hereinafter referred to as PMS) were precipitated. After removing aggregates using a 149 μm mesh sieve, the fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for one day. Observation of the obtained fine particles using a scanning electron microscope revealed that they were porous particles with a diameter of approximately 20 μm (Figure 5).

[0043] <Example 2> A solution was prepared by dissolving 60 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 200 mg of ethylcellulose (Karacon ETHOCEL STD7), and 120 mg of Suppocire AM (GATTEFOSSE) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol. This solution was then emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1 M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained particles were observed using a scanning electron microscope (Figure 6).

[0044] <Example 3> A solution was prepared by dissolving 80 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 200 mg of ethylcellulose (Karacon ETHOCEL STD7), and 120 mg of Suppocire AM (GATTEFOSSE) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol. This solution was then emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained particles were observed using a scanning electron microscope (Figure 7).

[0045] <Example 4> A solution was prepared by dissolving 100 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 200 mg of ethylcellulose (Karacon ETHOCEL STD7), and 120 mg of Suppocire AM (GATTEFOSSE) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol. This solution was then emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained particles were observed using a scanning electron microscope (Figure 8).

[0046] <Example 5> A solution prepared by dissolving 60 mg of hypromellose phthalate (Shin-Etsu Chemical HP55) and 200 mg of ethylcellulose (Karacon ETHOCEL STD7) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol was emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1 M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, the fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained fine particles were observed using a scanning electron microscope (Figure 9).

[0047] <Example 6> 60 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 200 mg of ethylcellulose (Karacon ETHOCEL STD7), and 120 mg of GELUCIRE43 / 01 were dissolved in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol. To this solution, 50 μL of 0.5% Carbopol (BFGoodrich Carbopol 934) aqueous solution and 5 μL of sorbitan monooleate were added, and the mixture was sonicated for 1 minute under ice cooling with 6 notches on the tip sonication scale. This solution was then emulsified in 5 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 8000 rpm for 3 minutes. After emulsification, 20 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, the fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for one day. The obtained fine particles were observed using a scanning electron microscope (Figure 10).

[0048] <Example 7> A solution was prepared by dissolving 120 mg of hypromellose phthalate (Shin-Etsu Chemical HP55), 400 mg of ethylcellulose (Karacon ETHOCEL STD7), and 240 mg of GELUCIRE 43 / 01 (GATTEFOSSE) in a mixture of 4 mL of methylene chloride and 1 mL of ethanol. This solution was then emulsified in 10 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 6000 rpm for 3 minutes. After emulsification, 40 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained particles were observed using a scanning electron microscope (Figure 11).

[0049] <Example 8> A solution was prepared by dissolving 120 mg of hydroxymethylcellulose succinate acetate (DUPONT ANFINISOL AS126G), 400 mg of ethylcellulose (Karacon ETHOCEL STD7), and 240 mg of GELUCIRE 43 / 01 (GATTEFOSSE) in a mixture of 4 mL of methylene chloride and 1 mL of ethanol. This solution was then emulsified in 10 mL of 0.5% polyvinyl alcohol (Kuraray Kuraray Poval 220C)-0.1M hydrochloric acid solution using a homogenizer (IKA Ultra-Turrax T18) at 6000 rpm for 3 minutes. After emulsification, 40 mL of purified water was added, and the solvent was removed by stirring with a stirrer for 3 hours. After removing aggregates using a 149 μm mesh sieve, fine particles were collected using a 20 μm mesh sieve. After washing with purified water, the particles were dispersed in a small amount of purified water and freeze-dried for 1 day. The obtained particles were observed using a scanning electron microscope (Figure 12).

[0050] <Example 9> (Preparation of semiporous Janus administration solution) 112.5 mg of a suspension containing 10 U of human insulin (Nacalai Tesque 28.5 U / mg), 1 mg of Laborazole (Gattefosse), 1 mg of decanoic acid, and 1 mg of polyoxyethylene hydrogenated castor oil (HCO60 Nikko Chemicals) per 15 mg was impregnated into 75 mg of the microparticles from Example 7, and then dried under reduced pressure at room temperature for 1 day. 90 mg of 0.5% Carbopol aqueous solution (BFGoodrich Carbopol 934) was added to the vacuum-dried microparticles to impregnate them, and then vacuum-dried to completely remove moisture. 112.5 mg of Suppocire AM (Gattefosse) and 451.5 mg of soybean oil were added, and the microparticles were dispersed using a bath sonicator to prepare the porous Janus administration solution. When 75 mg of this solution is administered to a 170 g rat, it corresponds to the following amounts per kg of body weight: 10 mg of microparticles, 10 U of insulin, 1 mg of laborazole, 1 mg of decanoic acid, 1 mg of polyoxyethylene hydrogenated castor oil, and 60 μg of carbopol.

[0051] (Control 1: Preparation of ethylcellulose porous microsphere administration solution) A suspension containing 10 U of human insulin (Nacalai Tesque 28.5 U / mg), 1 mg of Laborazole (Gattefosse), 1 mg of decanoic acid, and 1 mg of polyoxyethylene hydrogenated castor oil (Nikko Chemicals HCO60) per 15 mg was impregnated into 75 mg of microparticles of control example 1, and then dried under reduced pressure at room temperature for 1 day. 90 mg of 0.5% Carbopol (BFGoodrich Carbopol 934) aqueous solution was added to the vacuum-dried microparticles for impregnation, and then vacuum-dried to completely remove moisture. 112.5 mg of Suppocire AM (Gattefosse) and 451.5 mg of soybean oil were added, and the microparticles were dispersed using a bath sonicator to prepare a porous microsphere administration solution. When 75 mg of this solution is administered to a 170 g rat, it corresponds to the following amounts per kg of body weight: 10 mg of microparticles, 10 U of insulin, 1 mg of laborazole, 1 mg of decanoic acid, 1 mg of polyoxyethylene hydrogenated castor oil, and 60 μg of carbopol.

[0052] (Control 2: Aqueous solution containing an absorption enhancer) When 50 mg was administered to a 170 g rat, an aqueous solution was prepared so that the amounts per kg of body weight were 10 mg of microparticles, 10 U of insulin, 1 mg of laborazole, 1 mg of decanoic acid, 1 mg of polyoxyethylene hydrogenated castor oil, and 60 μg of carbopol. This solution was then prepared as an aqueous solution containing an absorption enhancer.

[0053] (Control 3: Insulin-containing saline preparation) When 50 mg was administered to a 170 g rat, a saline solution was prepared that resulted in 10 U of insulin per kg of body weight, and this was designated as insulin-containing saline.

[0054] (Rat small intestine administration experiment) Male Wistar rats weighing 170 g were fasted overnight, then their abdomens were opened, and the jejunum was removed. Each rat was administered 75 mg of porous Janus solution, 75 mg of porous microsphere solution, 50 mg of an absorption-enhancing aqueous solution, and 50 mg of insulin-containing saline via syringe. 100 μL of blood was collected from the jugular vein before and after administration, and the plasma was collected by centrifugation at 16,000 rpm for 3 minutes at 4°C. The collected plasma was frozen and stored at -80°C until plasma glucose measurement was performed.

[0055] (Measurement of plasma glucose concentration) The glucose was measured using the Wako Glucose Test Kit (Fuji Wako Pure Chemical Industries) at 505 nm absorbance.

[0056] Figure 13 shows the changes in plasma glucose concentration after administration of each formulation. In control 2 (aqueous solution containing an absorption enhancer) and control 3 (insulin-based saline), blood glucose levels tended to rise after blood sampling. In control 1 (ethylcellulose porous microsphere administration solution), the rise in blood glucose levels in controls 2 and 3 was suppressed, but only a slight decrease in blood glucose levels was observed. On the other hand, the porous Janus of the present invention showed a blood glucose-lowering effect for 3 hours. Since it is impregnated as an aqueous suspension, it is thought that the absorption enhancer and the mucosal adhesive polymer Carbopol are distributed on the porous side. The porous side where Carbopol is distributed adheres to the mucous membrane, and the encapsulated insulin is released to the mucous membrane side.

[0057] In this case, it is thought that the non-porous hemisphere acts as a backing, suppressing drug release into the lumen. Furthermore, the non-porous hemisphere is thought to protect the porous hemisphere (containing insulin), which is located on the lumen side and attached to the mucosa, from enzymes and other factors. On the other hand, in porous microspheres, there is no backing, and release into the lumen and enzymatic attack cannot be suppressed. Therefore, it is thought that the porous Janus of the present invention was able to efficiently deliver the drug to the mucosa side of the absorption surface.

[0058] <Example 10> A solution was prepared by dissolving 390 mg of hypromellose phthalate (Shin-Etsu Chemical HP55) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol (HP55 solution), a solution was prepared by dissolving 200 mg of ethylcellulose (Colorcon ETHOCEL STD7) and 120 mg of GELUCIRE 43 / 01 (GATTEFOSSE) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol (EC-GE solution), and a solution was prepared by dissolving 320 mg of ethylcellulose (Colorcon ETHOCEL STD7) in a mixture of 2 mL of methylene chloride and 0.5 mL of ethanol (EC solution). A few drops of each solution were spread onto a glass preparation and left to dry overnight at room temperature to form a film (HP55 film was prepared from the HP55 solution, EC-GE film from the EC-GE solution, and EC film from the EC solution). 5 μL of purified water was placed on each film, and the contact angle was measured by the dropwise method. The values ​​were calculated using the θ / 2 method. The results are shown in Table 1. Since the contact angle indicates wettability, the wettability was in the order of HP55 > EC >> EC-GE. In the microparticles of Example 7, the HP55 film corresponds to the composition of porous hemispheres, and the EC-GE film corresponds to hemispheres without pores. From this, it can be seen that the contact angles between hemispheres differed greatly in the microparticles of Example 7, and when water was added to these Janus microparticles, it was thought that the impregnation occurred through the porous hemispheres with smaller contact angles and better wettability. Furthermore, since the wettability of the EC film was only slightly inferior to that of the HP55 film, it is thought that the addition of GELUCIRE 43 / 01 could increase the difference in wettability between hemispheres, allowing the drug-containing aqueous solution to avoid distribution on the poorly wetted non-porous hemispherical surface and to be impregnated into the more wettable porous hemispheres.

[0059] [Table 1]

Claims

1. Janus microparticles having a particle size of 0.01 to 5000 μm, comprising a porous hemispherical portion containing hypromellose phthalate or hydroxymethylcellulose acetate succinate and a non-porous hemispherical portion containing ethylcellulose, wherein at least the non-porous hemispherical portion further contains wax, and the wetting of the porous hemispherical portion with water is better than that of the non-porous hemispherical portion.

2. Janus microparticles according to claim 1, wherein the porous hemispherical portion contains a drug.

3. The Janus microparticle according to claim 2, wherein the drug is a peptide, protein, nucleic acid, or nucleic acid derivative.

4. The Janus microparticle according to claim 1, wherein the porous hemispherical portion contains an absorption enhancer, a protease inhibitor, a mucosal adhesion polymer, and a sol-gel agent.

5. A method for producing Janus microparticles according to any one of claims 1 to 4, comprising the following steps (i) and (ii). (i) A step of emulsifying a solution obtained by dissolving hypromellose phthalate or hydroxymethylcellulose succinate acetate, ethylcellulose, and wax in a common solvent in an aqueous solution containing a surfactant; and (ii) A step of drying the emulsion to remove the solvent.

6. The method according to claim 5, wherein the volume of the surfactant-containing aqueous solution is 0.5 to 10 times the volume of the solution obtained by dissolving hypromellose phthalate or hydroxymethylcellulose acetate succinate and ethylcellulose in a common solvent.

7. The method according to claim 5 or 6, wherein in step (ii), the emulsion is dried for 30 minutes or more to remove the solvent.

8. After step (ii), (iii) A step of impregnating a porous hemisphere with an aqueous solution or suspension of a drug. The method according to any one of claims 5 to 7, further comprising:

9. The method according to any one of claims 5 to 8, wherein the surfactant is a nonionic surfactant.

10. The method according to any one of claims 5 to 9, wherein the surfactant is polyvinyl alcohol.

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