JP2015140328A - Silk fibroin solution, and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a percutaneous absorption preparation having excellent sustained-release properties and percutaneous absorption properties.SOLUTION: A percutaneous absorption preparation including a high molecular weight silk fibroin, a cyclic compound, and an active ingredient is used. The percutaneous absorption preparation may further include a guanidino group-containing compound. The cyclic compound may be a cyclic oligosaccharide, or an active ingredient-including cyclic compound.

Description

  The present invention relates to a transdermal absorption agent.

  Cyclic compounds such as cyclodextrin (CD) are generally used as components that promote the “sustained release performance” of active ingredients contained in cosmetics and therapeutic agents. The mechanism by which the cyclic compound promotes the sustained release performance is typically due to the cyclic compound including the low molecular weight active ingredient and then gradually releasing the inclusion substance. Moreover, since a cyclic compound can include an active ingredient, it is also used to stably maintain a slightly water-soluble active ingredient in water. Cosmetics and therapeutic agents using cyclic compounds are described in Patent Documents 1 to 3, for example.

JP 61-227517 Special table 2008-514198 JP2005-22975

  However, the cyclic compound has an effect of improving the sustained release of the active ingredient, but has no effect of promoting the transdermal absorbability of the active ingredient after the sustained release. That is, when only a cyclic compound is added to cosmetics, therapeutic agents, etc., the sustained release effect of the active ingredient can be expected, but the effect of promoting percutaneous absorption cannot be expected. For this reason, in Patent Documents 1 to 3 described above, high transdermal absorbability could not be imparted to the cyclic compound aqueous solution in which the active ingredient was dissolved.

  This invention is made | formed in view of the said situation, and it aims at providing the agent for percutaneous absorption excellent in the sustained release and transdermal absorbability of an active ingredient.

  The inventors of the present application have found that, when high molecular weight silk fibroin is added to a pharmaceutical aqueous solution containing a cyclic compound as described in the examples described later, the transdermal absorbability of the drug is improved, and the present invention is based on the results. It came to complete. At this time, when the guanidino group-containing compound was further added, the aqueous solution state of the mixed solution could be maintained for a long time.

  That is, according to one aspect of the present invention, there is provided a transdermal absorption preparation containing a high molecular weight silk fibroin, a cyclic compound, and an active ingredient.

  Moreover, according to one aspect of the present invention, there is provided a method for producing a transdermal absorption agent comprising a step of mixing high molecular weight silk fibroin, a cyclic compound, and an active ingredient.

  Moreover, according to one aspect | mode of this invention, the base material for transdermal absorption agents containing high molecular weight silk fibroin and a cyclic compound is provided.

  Moreover, according to one aspect of the present invention, the cyclic compound may be a cyclic oligosaccharide or a cyclic compound for containing an active ingredient. Moreover, according to one aspect of the present invention, the cyclic compound may be one or more of cyclodextrins or cyclodextrin derivatives. Moreover, according to one aspect of the present invention, the agent for transdermal absorption may further contain a guanidino group-containing compound. Moreover, according to one aspect of the present invention, the agent for transdermal absorption may be a cosmetic, a medicated cosmetic, a therapeutic agent, a quasi-drug, or an external drug.

  According to the present invention, a transdermal absorption agent excellent in sustained release and transdermal absorbability of an active ingredient can be obtained.

FIG. 1 is a diagram showing the results of subjecting a low-molecular fibroin aqueous solution and a high-molecular fibroin aqueous solution to SDS-PAGE. FIG. 2 shows the result of HPLC measurement of 7-methoxycoumarin. FIG. 3 shows the results of HPLC measurement of fibroin. FIG. 4 shows the results of HPLC measurement of glycine. FIG. 5 shows the results of HPLC measurement of alanine. FIG. 6 is a table showing an outline of the results of the HPLC measurement. FIG. 7 is a diagram showing the results of a percutaneous absorption test performed on a sample solution containing high molecular weight silk fibroin. FIG. 8 is a diagram showing the results of a transdermal absorption test performed on a sample solution containing low molecular weight silk fibroin.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, in order to avoid the repetition complexity about the same content, description is abbreviate | omitted suitably.

  One embodiment of the present invention is a transdermal absorption preparation containing a high molecular weight silk fibroin, a cyclic compound, and an active ingredient. This agent for transdermal absorption is excellent in the transdermal absorbability of the active ingredient as described in the examples described later. Moreover, this transdermal absorption agent can maintain a slightly water-soluble active ingredient stably in water, when a cyclic compound includes an active ingredient. This transdermal absorption agent can release the active ingredient gradually.

  In one embodiment of the present invention, “silk fibroin” includes one type of fibrous protein that can be purified from straw. Silk fibroin may be purified by the method described in WO2006 / 101223, for example. Silk fibroin is typically characterized by a high proportion of glycine, alanine, serine, and tyrosine. The silk fibroin may be, for example, silk fibroin derived from an organism classified as Lepidoptera, Bee, or Spider. Spiders can be obtained, for example, from a nest. Silk fibroin may be silk fibroin obtained by a genetic recombination technique. The GenBank Accession No. of silk fibroin may be AF226688.1, for example.

  The Lepidoptera includes, for example, the silkworm family, the mosquito family, the lobster family, the lobster family, and the scorpion family. The silkworm family includes, for example, the silkworm genus as a subclass. Examples of the silkworm genus include silkworm and mulberry. In one embodiment of the present invention, “蚕” may be a living organism classified into the silkworm family. In addition, the silkworm may be, for example, a genetically modified silkworm, a rabbit, a sericin silkworm, or a wild silkworm. Silk fibroin is preferably derived from the silkworm family, and more preferably derived from the genus Bombycidae, from the viewpoint of increasing the transdermal absorbability of the transdermal absorption agent.

  The order of the bees includes, for example, a bee family, a wasp family, and an ant family. Moreover, the wasp family includes, for example, a wasp genus, a cross wasp genus, a hornet hornet genus, or a genus wasp genus as a subclass. The wasp genus includes, for example, kiros hornet, giant hornet, hornet hornet, hornet hornet, chiros hornet, hornet hornet as a subclass.

  The order of the spider is, for example, a spider spider family, a giant spider family, a monomorphic area, an old sieving board, a completeness area, and a non-sieving board. Non-sieving plates include, for example, Niwaonigamo and Nagakogaegumo as subclasses.

  In one embodiment of the present invention, the molecular weight of the “high molecular weight silk fibroin” may be, for example, 15, 20, 25, 37, 50, 75, 100, 150, 200, 250, 300, 400, or 500 kDa or more. Well, any two of them may be within the range of values. This molecular weight is preferably 25 kDa or more, more preferably 35 kDa or more, and most preferably 50 kDa or more, from the viewpoint of increasing the transdermal absorbability of the transdermal absorption agent. The molecular weight may be evaluated by, for example, subjecting the purified sample to non-reducing SDS-PAGE and evaluating the molecular weight in the region where the strongest band was observed. In addition, for example, evaluation may be performed by density gradient ultracentrifugation, gel filtration chromatography, or MS-MS. In one embodiment of the present invention, the “low molecular weight silk fibroin” refers to, for example, a silk fibroin having a low molecular weight and an increased water solubility (for example, a low molecular weight silk proteolytic peptide, hydrolyzed silk, or silk Extract).

  In one embodiment of the present invention, the “cyclic compound” may have pores capable of including components such as active ingredients therein. It is desirable that the inside of the pores be hydrophobic in order to facilitate inclusion of hydrophobic molecules. The inner diameter of the pores of the cyclic compound may be, for example, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, or 1.5 nm or more, and is within the range of any two of them. May be. Moreover, a cyclic compound contains the cyclic compound which can release an active ingredient gradually. The cyclic compound is not particularly limited as long as it can contain components such as active ingredients, and may be, for example, a cyclic oligosaccharide or a cyclic compound for containing active ingredients. The cyclic oligosaccharide or the active compound-containing cyclic compound may be, for example, a cyclodextrin or a cyclodextrin derivative. The number of sugars contained in the cyclic oligosaccharide or the cyclic compound for inclusion of the active ingredient is not particularly limited as long as it can contain the active ingredient, for example, 3, 4, 5, 6, 7, 8, 9, 10, The number may be 11 or 12, and may be within the range of any two of them. The cyclic compound is preferably one or more of cyclodextrins or cyclodextrin derivatives from the viewpoint of increasing the transdermal absorbability of the agent for transdermal absorption.

  In one embodiment of the present invention, “cyclodextrin (CD)” is a kind of cyclic oligosaccharide. CD includes, for example, D-glucose bound by α-1,4 glucoside bonds, and includes α-CD, β-CD, γ-CD, HP-β-CD, and the like. CD is preferably HP-β-CD from the viewpoint of increasing the transdermal absorbability of the transdermal absorption agent or suppressing the solidification of the transdermal absorption agent. The number of sugars contained in the CD may be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, and is within the range of any two of them. Also good. CD may be in a chemically modified or unmodified form, and may form a multimer. The CD may be, for example, glycosylated, maltosylated, methylated, hydroxyalkylated, acylated, ionized, sulfated, phosphorylated CD. The methylated CD may be, for example, 2,6-di-O-methyl-α, β, γ-CD, or 2,3,6-tri-O-methyl-α, β, γ-CD. . Hydroxyalkylated CD is, for example, 2-hydroxyethyl-α, β, γ-CD, 2-hydroxypropyl-α, β, γ-CD, 3-hydroxypropyl-α, β, γ-CD, or 2,3-hydroxypropyl It may be -α, β, γ-CD. The alkylated CD may be, for example, 2,6-di-O-ethyl-α, β, γ-CD, or 2,3,6-tri-O-ethyl-α, β, γ-CD. . The acylated CD may be, for example, 2,3,6-tri-O-acyl-α, β, γ-CD. The ionized CD may be, for example, O-carboxylmethyl-O-ethyl-α, β, γ-CD. CD may be obtained, for example, by allowing cyclomaltodextrin glucanotransferase to act on starch. CDs may be purchased from companies such as Wako Pure Chemical Industries. In one embodiment of the present invention, the “cyclodextrin derivative” is not particularly limited as long as it can contain components such as active ingredients.

  In one embodiment of the present invention, the “active ingredient” includes, for example, an ingredient exhibiting physiological activity among ingredients contained in cosmetics, medicated cosmetics, therapeutic drugs, quasi drugs, or external drugs. Active ingredients include, for example, whitening components, skin-beautifying components, skin conditioning components, antioxidant components, anti-ultraviolet components, anti-smudge components, anti-wrinkle components, anti-sagging components, anti-drying components, anti-dulling components, anti-pigmentation components , An anti-acne component, an angina component, an anti-pain component, an antidementia component, an anti-Parkinson's disease component, and the like. The active ingredient may be hydrophobic, and may be a low molecular weight compound or a polymer compound. When the active ingredient is a low molecular weight compound, its molecular weight may be, for example, 50, 100, 150, 200, 300, 500, 1000, 2500, 5000, 10,000 or less, and within the range of any two of them. It may be. Furthermore, from the viewpoint of transdermal absorbability, it is preferably 2000 or less, more preferably 1000 or less.

  In the embodiment of the present invention, the “dosage form” of the agent for transdermal absorption may be, for example, a patch, a coating agent, a solution, a suspension, a spray, an aerosol, or the like. In the transdermal absorption agent, the concentration of high molecular weight silk fibroin is, for example, 0.001, 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 5, 7.5, 10, or 50% (w / w) It may be above, or may be within the range of any two of them. This concentration is preferably from 0.1 to 5.0% (w / w), more preferably from 0.5 to 3% (w / w), from the viewpoint of increasing the transdermal absorbability of the agent for transdermal absorption. In the transdermal absorption agent, the concentration of the cyclic compound may be, for example, 1, 10, 15, 50, 100, 150, 200, 250, 300, 350, 400, or 500 mM or more, and any two of them It may be within the range of values. This concentration is preferably from 100 to 300 mM, more preferably from 120 to 250 mM, from the viewpoint of increasing the sustained release ability of the transdermal absorption agent or increasing the water stabilization ability of the active ingredient. In the percutaneous absorption agent, the concentration of the active ingredient may be, for example, 0.1, 0.5, 1, 5, 10, 25, 50, or 100 mM or more, and may be within the range of any two of them. Good. The pH of the agent for transdermal absorption may be, for example, 3, 4, 5, 6, 7, 8, or 9, and may be in the range of any two of them. The pH is preferably 4 to 8 from the viewpoint of maintaining the aqueous solution state of the transdermal absorption agent for a long period of time and suppressing hydrolysis. The transdermal absorbent may be a transdermal absorbent that can be stored for a long period of time. This storage period may be, for example, 10, 30, 60, or 90 days or more, and may be within the range of any two of them. The storage temperature of the transdermal absorbent is preferably 40 ° C. or lower, for example. This temperature may be, for example, 0, 5, 10, 15, 20, 25, 30, 35, or 40 ° C., and may be in the range of any two of them.

  From the viewpoint of suppressing solidification of the transdermal absorption agent or maintaining the aqueous solution state of the transdermal absorption agent for a long period of time, the transdermal absorption agent according to an embodiment of the present invention includes a guanidino group-containing compound. It is preferable to contain. The guanidino group-containing compound may be, for example, arginine, aminoguanidine, or a guanidino group-introduced amino acid. The concentration of the guanidino group-containing compound in the transdermally absorbable agent may be, for example, 1, 10, 50, 80, 100, 120, 150, 200, or 300, 500 mM, or any of these two values. It may be within the range. This concentration is preferably 80 to 120 mM, and more preferably 90 to 110 mM, from the viewpoint of suppressing solidification of the transdermal absorption agent or maintaining the aqueous solution state of the transdermal absorption agent for a long period of time.

  One embodiment of the present invention is a method for producing a percutaneous absorption preparation comprising a step of mixing high molecular weight silk fibroin, a cyclic compound, and an active ingredient. According to this production method, an agent for transdermal absorption excellent in transdermal absorbability of an active ingredient can be produced.

  One embodiment of the present invention is a transdermal absorption agent obtained through a step of mixing high molecular weight silk fibroin, a cyclic compound, and an active ingredient. This agent for transdermal absorption is excellent in transdermal absorbability of the active ingredient.

  One embodiment of the present invention is a substrate for an agent for transdermal absorption comprising high molecular weight silk fibroin and a cyclic compound. This substrate can be used to assist transdermal absorption of the active ingredients.

  One embodiment of the present invention is a transdermal absorption agent comprising a high molecular weight silk fibroin and an active ingredient-containing cyclic compound. This agent for transdermal absorption is excellent in transdermal absorbability of the active ingredient. The active ingredient-containing cyclic compound may be produced by mixing an active ingredient in an aqueous cyclic compound solution.

  One embodiment of the present invention is a transdermal absorption preparation comprising an aqueous high molecular weight silk fibroin solution, a cyclic compound, and an active ingredient. This agent for transdermal absorption is excellent in transdermal absorbability of the active ingredient. In one embodiment of the present invention, the “high molecular weight silk fibroin aqueous solution” is an aqueous solution containing high molecular weight silk fibroin as a main raw material.

  One embodiment of the present invention is a composition comprising high molecular weight silk fibroin, a cyclic compound, and an active ingredient. This composition is excellent in transdermal absorbability of the active ingredient. Moreover, this composition can maintain a slightly water-soluble active ingredient stably in water, when a cyclic compound includes an active ingredient. Moreover, this composition can release an active ingredient gradually. Moreover, this composition may also contain a guanidino group containing compound, for example.

  One embodiment of the present invention is a composition comprising high molecular weight silk fibroin and a cyclic compound. This composition can be used to assist transdermal absorption of the active ingredients.

  One embodiment of the present invention is a method for treating a disease, comprising a step of transdermally administering a composition comprising a high molecular weight silk fibroin, a cyclic compound, and an active ingredient to a patient.

  One embodiment of the present invention is a method for ameliorating or preventing symptoms, comprising a step of transdermally administering a composition comprising high molecular weight silk fibroin, a cyclic compound, and an active ingredient to a mammal. The symptom may be, for example, one or more selected from the group consisting of spots, wrinkles, sagging, dryness, dullness, pigmentation, and acne.

  One embodiment of the present invention is a cosmetic method comprising a step of transdermally administering a composition comprising high molecular weight silk fibroin, a cyclic compound, and an active ingredient to a human skin.

  One embodiment of the present invention is a composition comprising high molecular weight silk fibroin and a cyclic compound for use in transdermal administration. Transdermal administration includes, for example, administration forms such as sticking or application. Application includes dosage forms such as liquid application, cream application, spraying, or aerosol.

  One embodiment of the present invention is a method for producing an agent for transdermal absorption, which comprises a step of mixing a composition containing a high molecular weight silk fibroin and a cyclic compound and an active ingredient. According to this production method, an agent for transdermal absorption excellent in transdermal absorbability of an active ingredient can be produced.

  One embodiment of the present invention is the use of a composition comprising high molecular weight silk fibroin, a cyclic compound, and an active ingredient to produce a transdermal absorption agent. One embodiment of the present invention is the use of a composition comprising high molecular weight silk fibroin and a cyclic compound to produce a transdermal absorption agent.

  In one embodiment of the present invention, the “agent” is not particularly limited as long as it is a functional composition, and includes, for example, a concept including cosmetics, medicated cosmetics, therapeutic drugs, quasi drugs, or external drugs. is there. This agent may be a composition comprising an active ingredient and one or more pharmacologically acceptable carriers. The agent can be produced, for example, by any method known in the technical field of pharmaceutics by mixing the active ingredient and the carrier. The shape of the carrier is not particularly limited, and may be, for example, a solid or a liquid (for example, a buffer solution). The dose of the agent is not particularly limited, but may be, for example, 0.01 to 10,000 mg / kg body weight per time. Although the administration interval is not particularly limited, for example, it may be administered once every 1 to 30 days. The dose, administration interval, and administration method may be appropriately selected depending on the age, weight, symptom, target site, etc. of the subject. The agent preferably contains a cosmetically effective amount, a therapeutically effective amount, or an effective amount of an active ingredient that exhibits a desired action.

  In one embodiment of the present invention, “beauty” includes beautifying appearance, for example, whitening, beautification, skin conditioning, anti-oxidation, anti-ultraviolet rays, anti-wrinkle, anti-wrinkle, anti-sagging, anti-drying, anti-drying, Including actions such as dullness, anti-pigmentation, or anti-acne.

  In one embodiment of the present invention, “treatment” includes the ability to exert a symptom improving effect or a prophylactic effect of one or more symptoms associated with a patient's disease or disease.

  In one embodiment of the present invention, a “patient” is a human or non-human mammal (eg, mouse, guinea pig, hamster, rat, mouse, rabbit, pig, sheep, goat, cow, horse, cat, dog, marmoset, Including one or more monkeys or chimpanzees).

  In this specification, “or” is used when “at least one or more” of the items listed in the text can be adopted. The same applies to “or”. In this specification, when “in the range of two values” is specified, the range includes the two values themselves.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable. Moreover, it is also possible to adopt a combination of the configurations described in the above embodiments.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these.

<Example 1> Evaluation of transdermal absorbability of active ingredient The amount of skin permeation of the active ingredient was measured for the cyclodextrin (CD) aqueous solution containing the active ingredient by the following procedures (1) to (2). Further, when the high molecular weight silk fibroin was added and when the low molecular weight silk fibroin was added, the skin permeation amount of the active ingredient was measured.

(1) Preparation of mixed solution Control and sample solutions A to F having the component composition ratios shown in Tables 1 and 2 were prepared. A 2% high molecular weight silk fibroin aqueous solution was prepared by the following procedure. First, silk fibroin obtained by removing sericin from rabbits by refining was immersed in 20 mL of lithium bromide aqueous solution per 2.0 g and completely dissolved by shaking at 37 ° C. for 1 hour. This solution was placed in a cellulose tube and tied up, and desalted (dialyzed) in pure water at 60 ° C. After sufficiently dialyzing, the aqueous solution after dialysis was recovered, and pure water was added to make a 2% aqueous solution until the whole became 100 mL. Finally, after closing the lid of the container, it was left in an atmosphere of 60 ° C. for 30 minutes or more.

  A 2% low molecular weight fibroin aqueous solution prepared for comparison was prepared by subjecting a 2% high molecular weight silk fibroin aqueous solution to an autoclave treatment at 132 ° C. for 240 minutes. In addition, 2% low molecular weight fibroin aqueous solution and 2% high molecular weight fibroin aqueous solution were subjected to SDS-PAGE, and it was confirmed that high molecular weight fibroin was reduced in molecular weight by the above autoclave treatment (FIG. 1, lanes 2-4 and 5 respectively). -9). In Tables 1 and 2, 7-methoxycoumarin (ACROS ORGANICS, MW179.17) (final concentration 11.94 mM) is an active ingredient having a whitening effect, and arginine (final concentration 100 mM) is described in Example 2 described later. It is a component that suggests a solidification inhibiting effect of an aqueous solution. HP-β-CD (final concentration 150 mM) used was purchased from Nippon Shokuhin Kako Co., Ltd.

(2) Transdermal absorption experiment Franz-type cells were used for the transdermal absorption test. The receiver side was filled with purified water, and 32.5 ° C. water was refluxed in the water jacket, and the mixture was kept stirred by a stirrer. The membrane was attached to a Franz-type cell, and 1 mL of the control and sample solutions A to F were applied to the donor side. At this time, the skin of a hairless rat (male, 10 weeks old, abdomen) was used for the film. Thereafter, the receiver solution was sampled every hour, and the amount of 7-methoxycoumarin permeated was quantified by high performance liquid chromatography (HPLC). The cumulative permeation density (μg / cm ² ) per unit area of skin was plotted against the permeation time (h) (FIG. 7).
・ High-performance liquid chromatographic conditions Column: ODS particle size 5μm, inner diameter 4.6mm, length 150mm
Column temperature: 40 ° C
Mobile phase: Water / acetonitrile mixture (6: 4)
Flow rate: 1.0mL / min Injection volume: 20μL
Measurement wavelength: 325nm

  It has been confirmed that when fibroin, glycine and alanine are measured by HPLC under the same conditions as described above, no peak is detected at the same retention time as 7-methoxycoumarin (FIG. 2-6). Further, in this example, the quantitative evaluation was made by UV absorption at 325 nm where the UV absorption of fibroin was almost zero.

  From the results of FIG. 7, it was confirmed that the permeation amount of 7-methoxycoumarin at a certain measurement time increases as the concentration of high molecular weight fibroin contained in the sample increases. That is, it is suggested that the addition of high molecular weight fibroin contributes to the promotion of transdermal absorbability. Furthermore, for comparison, a similar experiment was performed using a fibroin aqueous solution that had been reduced in molecular weight by thermal decomposition in an autoclave (FIG. 8). In other words, it suggests that low molecular weight fibroin does not show the effect of promoting transdermal absorption. From the above, it was found that the transdermal absorbability of 7-methoxycoumarin is a phenomenon that can be seen only when fibroin is a polymer. That is, fibroin needs to be a polymer for promoting transdermal absorbability.

<Example 2> Evaluation of aqueous solution state
(1) Counting days until solidification An aqueous solution in which high molecular weight silk fibroin is dissolved may solidify (gel or precipitate) after standing for a long period of time. In Example 2 (1), the number of days until solidification when an aqueous solution containing CD and high molecular weight silk fibroin was allowed to stand at 40 ° C. was measured. At this time, four types of CD, α-type, β-type, γ-type, or β-type having a hydroxypropyl group (HP) in the side chain, were used. Below, each cyclodextrin is abbreviated as α-CD, β-CD, γ-CD, and HP-β-CD. Since β-CD has a low saturation solubility, only a concentration of 15 mM could be tried. On the other hand, α-CD, γ-CD and HP-β-CD were tested at a concentration of 100 mM or more.
Also, an aqueous solution containing CD and high molecular weight silk fibroin was prepared to pH 5.0 with dilute hydrochloric acid before standing. The concentration of the high molecular weight silk fibroin was adjusted so that the final concentration in the mixed solution was 1% (w / w). In addition, arginine, urea, aminoguanidine, or lysine was added with or without 100 mM, respectively. The results are shown in Table 3.

  As a result of Table 3, the aqueous solution containing CD and high molecular weight silk fibroin maintained the aqueous solution state for the longest time when HP-β-CD was used. In addition, when arginine or aminoguanidine (a guanidino group-containing compound) was added, the number of days until solidification was extended as compared with the case of no addition. Moreover, the effect by adding lysine was not recognized. Even when no additive was added, the aqueous solution was maintained for at least 9 days.

  In particular, in a system in which HP-β-CD was used for CD and arginine or aminoguanidine was added, the aqueous solution state was maintained even after 90 days had passed. This indicates that the number of days until solidification was extended by more than 30 times compared to the system of the combination of α-CD and urea that solidified earliest (3 days).

  Moreover, from the results in Table 3, the sample solutions A to C in Table 1 are aqueous solutions having a sustained release effect of active ingredients and highly efficient transdermal absorption performance even after being left for 90 days or more in an environment of 40 ° C. It can be said.

(2) Effect of CD In the same procedure as in (1) above, the CD concentration was set to 0, 10, 15, 100, or 150 mM, and the number of days until solidification was measured without adding additives. At this time, the reaction was carried out in the presence or absence of takadiastase. The results are shown in Table 4.

  Table 4 (i) shows the results when an aqueous solution containing CD and 1% high molecular weight silk fibroin was left at 40 ° C. (ii) shows the results when takadiastase acetate buffer (pH 5.0) was added 6-7 days after the start of the experiment under the condition (i). Takadiastase is an enzyme that degrades cyclodextrin. Preliminary tests have confirmed that Takadiastase exhibits effective degradation activity in acidic aqueous acetic acid at pH 5 containing 50 mM calcium chloride. “-” In the table means not implemented.

The solutions used in the above examples were prepared by the following procedure.
(A) pH 5.0 acetate buffer (50 mM CaCl ₂ )
1) 0.1 M acetic acid: 5.8 mL of acetic acid is diluted to 1 L with water.
2) 0.1M Na acetate: dilute 8.2g Na acetate (anhydrous) to 1L with water.
3) Mix 0.1M acetic acid and 0.1M Na acetate in the following ratio.
0.1M acetic acid / 0.1M Na acetate = 14.8mL / 35.2mL
4) Add 0.11098g of calcium chloride and dissolve (calcium chloride is added to stabilize the enzyme reaction).
5) Prepare the total volume to 100ML.

(B) Takadiastase acetate buffer (pH 5.0)
Add pH 5.0 acetate buffer to 0.1 g of Takadiastase to prepare 20 mL. Leave in a 40 ° C water bath for about 30 minutes. The filtrate obtained by filtering it and removing insolubles is taken as an aqueous solution of takadiastase (enzyme solution).

(C) Dilute hydrochloric acid Dilute 1 mL of hydrochloric acid to about 300-fold dilution with purified water.

  Table 5 shows manufacturers and standards of reagents used in the above examples.

  As a result of Table 4, when CD was added, the number of days until solidification of the polymer silk fibroin aqueous solution was increased as compared with the case where CD was not added. In particular, the effect of HP-β-CD was great, and the number of days until solidification was greatly increased by addition. Moreover, when cyclodextrin is decomposed by an enzymatic reaction, it is solidified in a short time, so it is clear that cyclodextrin contributes to solidification inhibition.

(3) Effect of temperature In the same procedure as in (1) above, set the standing temperature to 25 ° C or 0 ° C, set the CD concentration to 0, 10, 15, 100, or 150 mM, add the additives. The number of days until solidification was measured. The results are shown in Tables 6 and 7.

  It can be seen that the number of days required for solidification is greatly increased when the standing temperature is lowered. From this result, at a temperature lower than 40 ° C., it can be stably present as an aqueous solution for more than the number of days until solidification observed at 40 ° C.

  In the above, this invention was demonstrated based on the Example. It is to be understood by those skilled in the art that this embodiment is merely an example, and that various modifications are possible and that such modifications are within the scope of the present invention.

Claims (7)

  An agent for transdermal absorption, comprising high-molecular-weight silk fibroin, a cyclic compound, and an active ingredient.   2. The agent for transdermal absorption according to claim 1, wherein the cyclic compound is a cyclic oligosaccharide or a cyclic compound for inclusion of an active ingredient.   The agent for transdermal absorption according to claim 1, wherein the cyclic compound is one or more of cyclodextrin or a cyclodextrin derivative.   The agent for transdermal absorption according to any one of claims 1 to 3, further comprising a guanidino group-containing compound.   The agent for transdermal absorption according to any one of claims 1 to 5, which is a cosmetic, a medicated cosmetic, a therapeutic agent, a quasi-drug, or an external drug.   A method for producing an agent for transdermal absorption, comprising a step of mixing high molecular weight silk fibroin, a cyclic compound, and an active ingredient.   A base material for a transdermal absorption agent comprising a high molecular weight silk fibroin and a cyclic compound.