JPH0579666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel clathrate compound consisting of tolnaftate and methylated cyclodextrin, and an antifungal agent containing the same.

[Background of the invention] Tolnaftate has excellent antibacterial activity against fungi, and can be used to treat fungal diseases such as ringworm, ringworm, and ringworm. It is a topical drug that is frequently used as a treatment for.

For skin diseases, especially diseases caused by fungi such as tinea hidraformis, it is necessary to select an appropriate dosage form depending on the site of the skin disease and various symptoms of the affected area. However, tolnaftate is a crystalline powder,
A water-soluble external powder that is extremely difficult to dissolve in water.
It has not been possible to create a formulation that utilizes water solubility, such as an aqueous external solution.

Tolnaftate-containing preparations include tinctures using a volatile solvent capable of dissolving tolnaftate, tinctures prepared by dissolving tolnaftate in a specific tolnaftate dissolving agent such as crotamiton and diethyl sebacate, and dissolving this in a solvent such as ethanol, and crotamiton. Creams prepared by emulsifying a solution of crotamiton and the like with an aqueous carboxyvinyl polymer solution, ointments prepared by mixing a carboxyvinyl polymer with a solution of crotamiton, and ointments mainly containing macrogol are known.

However, tinctures are highly irritating due to their volatile solvents, making them unsuitable for skin diseases where the affected area is broken or eroded.Furthermore, tinctures containing only volatile solvents cause crystals to precipitate as the solvent evaporates due to body temperature, making them ineffective. However, there are drawbacks that cannot be expected.

In addition, ointments and creams should be used for moist skin diseases, such as stickiness, release of body fluids and preparations, and
Not only do they have drawbacks such as soiling of shoes and discomfort, but also crystals precipitate over time if they have poor compatibility or affinity with the base.

Recently, a topical tolnaftate powder, which is a mixture of tolnaftate powder and excipients such as talc and starch, has been used to avoid the above-mentioned problems with moist skin diseases. There were problems such as poor migration properties and insufficient medicinal efficacy.

On the other hand, an invention for producing a clathrate compound in which the water solubility is increased by freeze-drying an aqueous mixture containing a conventional water-insoluble or poorly water-soluble drug and cyclodextrin is known from JP-A-50-116617. ing. In addition, there are inventions in which cyclodextrin is applied to various drugs such as barbituric acid and chloramphenicol to form clathrate compounds for the purpose of solubilizing them (Japanese Patent Application Laid-open Nos. 49-36821 and 50-100217, etc.). Many are known.

However, tolnaftate's clathrate compounds have not been known at all, and according to the research of the present inventors, even if these inventions using cyclodextrin are applied to tolnaftate, they do not increase the water solubility of tolnaftate. I learned that there is a problem that I cannot do it.

[Structure of the Invention] In view of the above circumstances, the present inventors conducted intensive research to solve the above-mentioned problems by making tolnaftate solubilized in water. The present invention was completed based on the finding that it has excellent skin transferability and can be made into various formulations by taking advantage of its water solubility.

That is, the present invention aims to provide a clathrate compound of tolnaftate and methylated cyclodextrin, and an antifungal agent containing this clathrate compound as an active ingredient.

In the methylated cyclodextrin used in the present invention, 6 to 8 glucose molecules are α-1,
It is a compound in which the hydroxyl group in the molecule of α, β, γ-cyclodextrin, which is cyclically bonded with four bonds, is methyl etherified.

In the present invention, the methylated cyclodextrin is particularly preferably methylated β-cyclodextrin, especially 2,6-di-O-methyl-
β-cyclodextrin is most preferred.

2,6-di-O-methyl-β-cyclodextrin is a derivative of β-cyclodextrin in which the 2 and 6 positions of each glucose residue are selectively methylated.

In addition, methylated cyclodextrin is Tetra
-hedron, 24 , 803 (1968).

The clathrate compound of the present invention can be produced by contacting tolnaftate and methylated cyclodextrin in a solvent. Specifically, it is manufactured by the method exemplified below.

That is, the clathrate compound of tolnaftate is prepared by preparing an aqueous solution of methylated cyclodextrin, adding tolnaftate as it is or as a solution dissolved in an organic solvent such as methanol, ethanol, or acetone that has an affinity for water, and mixing. It can be manufactured by The mixture is
It is advantageous to use a suitable combination of means such as stirring, shaking, and ultrasonication.

If the clathrate is dissolved in solution,
Next, the solvent is removed, and if necessary, the product is isolated and purified by washing and drying. In addition, when the clathrate compound is obtained as a precipitate by cooling or the like, it is isolated and purified by filtration or centrifugation, washing, and drying.

Furthermore, the clathrate compound of the present invention can be prepared by dissolving the methylated cyclodextrin and tolnaftate in an organic solvent that dissolves at least tolnaftate, preferably an organic solvent that dissolves both, such as chloroform.
It can also be produced by dissolving or suspending it in carbon tetrachloride, acetone, ethyl methyl ketone, etc. and distilling off the solvent as it is, or by thoroughly mixing or kneading and then removing the solvent.

The obtained clathrate compound is purified by washing and drying if necessary.

In addition, in the present invention, the solvent is removed by freeze-drying,
This is done using methods such as distillation.

The fact that a clathrate compound of tolnaftate and methylated cyclodextrin was obtained can be confirmed by data such as X-ray diffraction of the product, differential thermal analysis, and quantitative determination of the product.

For example, according to differential thermal analysis, the clathrate compound obtained in Example 1 has a characteristic characteristic of tolnaftate itself.
The endothermic peak around 106℃ has disappeared,
Furthermore, according to X-ray diffraction data, it became amorphous and the peaks at 2θ 21° and 23°, which are characteristic of tolnaftate itself, disappeared, confirming that it was an clathrate compound. This phenomenon was observed when tolnaftate and 2,6-di-O-methyl-β were mixed in a mortar.
- Not observed in mere physical mixture with cyclodextrin.

[Effects of the Invention] The tolnaftate-methylated cyclodextrin clathrate compound provided by the present invention has significantly increased water solubility than tolnaftate, and dissolves tolnaftate at a high concentration in an aqueous solution. Therefore, the present invention not only diversifies the formulation dosage form of tolnaftate, but also has the advantage of making formulation extremely easy. In addition, the tolnaftate-containing preparation of the present invention is significantly superior in terms of skin penetration, and can be expected to have reliable efficacy as an antifungal agent, lower volume, and reduce toxicity, and has problems associated with conventional powders. You can try to resolve the points.

Below, the effects of the present invention will be explained in more detail by listing the solubility test using the solubility method of the clathrate compound, the dissolution test using the beaker method, and the skin migration experiment using mice and their results.

A Solubility method test (1) The clathrate compound-containing aqueous solution (0.025M to 0.25M) obtained in Example 2 and 5 mg of tolnaftate
was added to water and treated in the same manner as in Example 2 to prepare a solution. Using these, each system was heated at 10°C according to the solubility method.
The total concentration of tolnaftate was measured.
The results are shown in Figure 1.

As is clear from Figure 1, the result is a straight line that passes approximately through the origin, and the solubility of tolnaftate in the tolnaftate clathrate is 2,6-di-O-
A linear function proportional to the concentration of methyl-β-cyclodextrin is shown. Showing the regression equation and correlation coefficient, y=8.171+4182x and r=0.9979.

(2) A similar experiment was applied to α, β, γ-cyclodextrin and the total tolnaftate concentration in each system was measured, but no improvement in solubility was observed in any of the systems for any cyclodextrin. This result indicates that, at least with cyclodextrin, no clathrate is formed that would increase the solubility of tolnaftate.

B Dissolution test 100 mg of the clathrate compound obtained in Example 1
Weigh it out, add it to 20 ml of water, and continue stirring at 500 rpm using a magnetic stirrer. Take 2 ml of the solution at regular intervals and add 2 ml of water to the beaker so that the total volume is always 20 ml. Filter the sample solution using a Millipore filter, collect 1 ml of the sample solution, add 4 ml of methanol, dilute with 80% methanol aqueous solution, top up with a 10 ml volumetric flask, and measure the absorbance of this sample solution. A similar operation is performed on a physical mixture of tolnaftate and 2,6-di-O-methyl-β-cyclodextrin (mixed in a mortar) and measured. The total concentration of tolnaftate in each system was determined using a calibration curve of tolnaftate using 80% methanol as a solvent. The results are shown in FIG.

As is clear from FIG. 2, the clathrate reached a maximum in 2 minutes and then showed a gentle elution curve. Almost no elution of tolnaftate was observed in any of the physical mixture systems. This result shows that when the clathrate compound of the present invention is made into an aqueous solution,
This shows that tolnaftate is eluted at a high concentration.

C Mouse skin migration test Tolnaftate-di-O-methyl-β-cyclodextrin clathrate compound obtained in Example 3 0.966g Zinc white 4.517g Potato starch 4.517g 10.0g powder and same as Example 3 The following formulation prepared by processing: tolnaftate 0.1g zinc white 4.95g potato starch 4.95g 10.0g was used.

The mouse is fixed face down on a board, the hair on the back of the mouse is trimmed with clippers without damaging the skin, and a 2 x 2 cm ² frame is used to define the area to which the external powder will be applied. Next, add 1 ml of water to 1 g of the external powder to make a slurry, and apply about 100 mg. (Note that water was added in consideration of the status of athlete's foot and the purpose of adhesion.) After a predetermined period of time, the mouse is decapitated and blood is collected.
In addition, 2×2 cm ² of skin was peeled off, cut into pieces with scissors, placed in a centrifuge tube containing 3 ml of 1.15% potassium chloride aqueous solution, and homogenized using an ultradisperser.

The collected blood is centrifuged at 3000 rpm for 10 minutes, and the supernatant serum is collected. More from now on
Weigh with a 200μ Etzpeldorf and add 200μ of water. Add 1 ml of internal standard (naphthol AS phenyl acetate) solution and 3 ml of dichloromethane, mix well for 30 seconds, centrifuge at 3000 rpm for 10 minutes, and separate the dichloromethane layer. Evaporate dichloromethane with nitrogen gas, then 75%
Add 100μ of methanol aqueous solution to prepare a sample for high performance liquid chromatography.

On the other hand, 1 ml of the internal standard solution and 3 ml of dichloromethane were added to the homogenized skin, and the same operations as above were performed to prepare a sample for high performance liquid chromatography.

The conditions for liquid chromatography were set as follows.

Mobile phase: 75% methanol Column packing material: Nucleosil ₅ C ₁₈ Flow rate: 1.5 ml/min Sensitivity: 0.02 (serum), 0.16 (skin) Wavelength: 222 nm The experimental results are shown in Figure 3. As is clear from Figure 3, the external powder of tolnaftate clathrate compound is
It is far superior to external powders containing tolnaftate alone in terms of skin penetration.

Tolnaftate provided by the present invention is
The powder or freeze-dried product obtained by the above production method can be used as it is as a powder or a liquid preparation that can be dissolved at the time of use. However, the powder or freeze-dried product usually contains starches such as corn starch and potato starch, magnesium carbonate, diatomaceous earth, bentonite, talc, kaolin, precipitated calcium carbonate, zinc white, titanium oxide, soft silicic acid anhydride, etc. Excipients, if necessary, formulation ingredients such as antioxidants, colorants, flavorings, and other medicinal ingredients in powder form or in the form of powder are mixed to prepare a powder for external use. In addition, other medicinal ingredients, absorption enhancers, colorants, flavoring agents, etc. may be added to the powder or freeze-dried product as necessary.
A liquid preparation can be obtained by adding an antioxidant and the like and dissolving it by adding purified water, a hydrophilic solvent such as ethanol, or a mixed solvent thereof.

Furthermore, the formulation of the present invention can be formulated in any manner that utilizes water solubility, and is not necessarily limited to powders or liquids. Furthermore, it is also possible to formulate a formulation containing an oil-soluble component by using a surfactant or the like in combination. Therefore, the clathrate compound of the present invention can be prepared into plasters such as plasters, sheets, films, or patches, emulsion preparations, or creams and ointments that are less sticky than existing products because of their excellent water solubility. You can also do that.

For patches such as patches and plasters, natural rubber, styrene-butadiene copolymer, styrene-isoprene-block copolymer, synthetic rubber such as silicone rubber, acrylic resin such as acrylic acid-acrylic acid ester copolymer, polyacrylic acid Bases such as sodium, methyl vinyl ether maleic anhydride copolymer, carboxymethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, gums such as xanthan gum, and if necessary, nonionic surfactants, urea, absorption enhancers such as medium-chain fatty acid monoglycerides, and antiseptics. It is manufactured by mixing an oxidizing agent, a softening agent, a flavoring agent, a preservative, an organic acid, and other medicinal ingredients to form a paste, which is then spread on a support. Carboxyvinyl polymers are preferably used as bases for creams and ointments.

These preparations should be selected in an appropriate dosage form, taking into account the type of fungal disease, disease site, degree and scope of the disease, symptoms, especially whether they are wet or dry, and whether there is rupture or erosion. .

The content of the tolnaftate-methylated cyclodextrin clathrate in the formulation varies depending on the molar ratio of the clathrate and the formulation dosage form, but is, for example, 1:1.
When using a clathrate compound with a molar ratio of
When using a clathrate compound with a molar ratio of 1:2, the amount is about 0.15 to 15%, preferably about 0.75 to 9%. Administration varies depending on the dosage form, for example, powders, solutions, creams, etc. with the active ingredient content as described above.
In the case of ointments, emulsion preparations, etc., take this once a day.
By spraying or applying ~6 times,
In the case of a patch, it is applied twice a day to once every few days to ensure sustained skin transfer.

EXAMPLES The present invention will be explained in further detail with reference to Examples below. However, the present invention is not limited to the examples.

Example 1 Tolnaftate 50mg (0.163M) and 2,6-
Di-O-methyl-β-cyclodextrin 216.5
mg (0.1225M), in a molar ratio of 1:1, were added to 30 ml of chloroform and completely dissolved, and the chloroform was distilled off using a continuous rotary evaporator (solvent distillation method). The powder was thoroughly dried in a desiccator to obtain a white powder of tolnaftate-2,6-di-O-methyl-β-.
Approximately 260 mg of cyclodextrin was obtained.

Figure 4 shows the differential thermal analysis data of this product. The results shown in Figure 4 show that the endothermic peak around 106°C, which is characteristic of the differential heat analysis data of tolnaftate alone shown in Figure 5, has disappeared, indicating that the crystal structure has been broken and it has been included in an amorphous form. show.

Moreover, the X-ray diffraction data of this product is shown in FIG.
The results shown in Figure 6 show that the characteristic peaks at 2θ21° and 23°, which are characteristic of the X-ray diffraction data of tolnaftate alone shown in Figure 7, have disappeared, and that it has become amorphous as a whole. The generation of was confirmed.

In addition, 2,6-di-O-methyl-β-cyclodextrin does not show an endothermic peak in differential thermal analysis (Figure 8), and in X-ray diffraction data, 2θ8°,
Characteristic peaks are observed at 10° and 17° (Figure 9).
Furthermore, in the differential thermal analysis data of a physical mixture of tolnaftate and 2,6-di-O-methyl-β-cyclodextrin (mixture made in a mortar), the endothermic peak of tolnaftate remains (the 10th
In the X-ray diffraction data, characteristic peaks mainly characteristic of 2,6-di-O-methyl-β-cyclodextrin are observed, and it is not in an amorphous form (Fig. 11).

Example 2 Ten Spitz tubes are prepared, and 5 mg of tolnaftate is weighed and put into each. On the other hand, 2,6-di-
16.6375g O-methyl-β-cyclodextrin
Weigh out and add water to it to make 0.25M2,6-di-
Make a 50 ml aqueous solution of O-methyl-β-cyclodextrin. Take a portion of this solution and
10, 2/10, 3/10, 4/10, 5/10, 6/10,
Diluted to 7/10 and 8/10, respectively, 0.025M,
0.05M, 0.075M, 0.1M, 0.125M, 0.15M,
0.175M, 0.2M 2,6-di-O-methyl-β-
Make a 10ml aqueous solution of cyclodextrin. Accurately measure 5 ml of each of these solutions using a whole pipette, and pour into each Spitz tube. (Put 5 ml of plain water into the remaining Spitz tube for the solubility test.) The Spitz tube was shaken for 10 minutes, placed in an ultrasonic bath for another 10 minutes, and then heated at a constant temperature of 10°C. I put it in the tank. Thereafter, the Spitz tube is taken out from time to time two to three times a day, and shaken for 10 minutes and sonicated for 10 minutes repeatedly to quickly reach an equilibrium state, and then returned to the constant temperature bath. Tolnaftate-2,6-di-
An aqueous solution of an O-methyl-β-cyclodextrin clathrate compound was obtained and subjected to the solubility method test described in A above.

The total concentration of tolnaftate dissolved in these aqueous solutions shows the values shown in FIG.

Example 3 (powder) Co-precipitate obtained in Example 1 (molar ratio 1:1)
0.966g, zinc white 4.517g and potato starch
Weigh out 4.517g and mix it evenly to make a total of 10g.
A powder for external use was obtained.

[Brief explanation of the drawing]

Figure 1 shows the tolnaftate dissolution test results using the solubility method of the clathrate compound of the present invention, Figure 2 shows the tolnaftate dissolution test results using the beaker method, Figure 3 shows the results of a mouse transdermal absorption experiment, and Figure 4 shows the results of the present invention. Figure 5 shows the differential thermal analysis data of the clathrate compound, Figure 5 shows the differential thermal analysis data of tolnaftate alone, Figure 6 shows the X-ray diffraction data of the clathrate compound of the present invention, and Figure 7 shows the X-ray diffraction data of tolnaftate alone. , Figure 8 shows the differential thermal analysis data of 2,6-di-O-methyl-β-cyclodextrin alone, and Figure 9 shows the differential thermal analysis data of 2,6-di-O-methyl-β-cyclodextrin.
Figure 10 shows the X-ray diffraction data of di-O-methyl-β-cyclodextrin alone, Figure 10 shows the differential thermal analysis data of the physical mixture, and Figure 11 shows the X-ray diffraction data of the physical mixture.
Linear diffraction data are shown for each.

Claims (1)

[Claims] 1. An inclusion compound consisting of tolnaftate and methylated cyclodextrin. 2. An antifungal agent characterized by containing an inclusion compound consisting of tolnaftate and methylated cyclodextrin.