External composition and method for stabilizing the same

Abstract

Provided is a composition for external use that has excellent high-temperature stability and a method for stabilizing the same. SOLUTION: The topical composition contains hypromellose and a dihydric alcohol.

Description

Technical Field

[0001] The present invention relates to an external composition and a method for stabilizing the same.

Background Art

[0002] For example, Patent Document 1 discloses an external composition containing a cellulose derivative containing hypromellose and a polyhydric alcohol that forms foam during use.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When an external composition is placed, for example, inside a vehicle or near a window, the temperature may rise and become high. If the high-temperature stability of the external composition is poor and aggregates such as gels are formed, clogging may occur, especially when the composition is filled in a pump container or the like. Patent Document 1 does not consider the high-temperature stability of the external composition. Therefore, an object of the present invention is to provide an external composition having excellent high-temperature stability and a method for stabilizing the same.

Means for Solving the Problems

[0005] An external composition according to one embodiment of the present invention contains hypromellose and a dihydric alcohol.

[0006] According to the above configuration, the high-temperature stability of the external composition can be improved.

Effects of the Invention

[0007] According to the external composition of the present invention, high-temperature stability can be improved, and in particular, the formation of aggregates can be suppressed even when the temperature exceeds 50°C. [Modes for carrying out the invention]

[0008] The topical composition of the present invention comprises hypromellose and a dihydric alcohol.

[0009] Hypromellose is hydroxypropyl methylcellulose, in which some of the hydroxyl groups of cellulose are replaced with methoxy or hydroxypropoxy groups. Hypromellose acts, for example, as a thickening agent to adjust the viscosity of topical compositions, or as a foaming agent to form foam when topical compositions are used.

[0010] Hypromellose comes in varieties with different degrees of substitution of methoxy or hydroxypropoxy groups. For example, as listed in the Japanese Pharmacopoeia, examples include hypromellose of substitution type 2910, with a methoxy group substitution of 28.0-30.0% and a hydroxypropoxy group substitution of 7.0-12.0%, hypromellose of substitution type 2906, with a methoxy group substitution of 27.0-30.0% and a hydroxypropoxy group substitution of 4.0-7.5%, and hypromellose of substitution type 2208, with a methoxy group substitution of 22.0-24.0% and a hydroxypropoxy group substitution of 8.5-10.5%. In the topical composition of the present invention, hypromellose of substitution type 2906 and hypromellose of substitution type 2208 are preferred for improving high-temperature stability, and hypromellose of substitution type 2208 is particularly preferred.

[0011] The lower limit of the amount of hypromellose in the topical composition is preferably 0.02 wt% or more, and more preferably 0.1 wt% or more. This allows for a suitable foamy consistency when the topical composition is filled into, for example, a foaming container and dispensed. On the other hand, the upper limit of the amount of hypromellose is preferably 0.8 wt% or less, and more preferably 0.4 wt% or less. This improves the feel (especially the slippery feeling) of the topical composition when it is used.

[0012] Examples of the dihydric alcohols mentioned above include propylene glycol, dipropylene glycol, 1,3-butylene glycol, ethylene glycol, and pentylene glycol. In the topical composition of the present invention, propylene glycol, dipropylene glycol, 1,3-butylene glycol, and pentylene glycol are preferred for improving high-temperature stability, and propylene glycol, dipropylene glycol, and 1,3-butylene glycol are particularly preferred. Furthermore, the dihydric alcohols may be used individually or in combination.

[0013] Furthermore, the lower limit of the amount of dihydric alcohol in the topical composition is preferably 3 wt% or more, and more preferably 9 wt% or more, in order to improve high-temperature stability. On the other hand, there is no particular upper limit to the amount of dihydric alcohol, but it is preferably 50 wt% or less.

[0014] The above topical composition preferably contains water. The amount of water in the above topical composition is preferably 90 wt% or less. In particular, using hypromellose of substitution degree type 2208 can improve high-temperature stability.

[0015] Furthermore, as described above, by including hypromellose and a dihydric alcohol in the topical composition, the high-temperature stabilization of the topical composition can be achieved. In other words, this can be described as a method for stabilizing a topical composition by coexisting hypromellose with a dihydric alcohol.

[0016] In the above-mentioned topical composition, the aggregates that form when the temperature rises are thought to originate from hypromellose. In other words, the above-mentioned topical composition can be said to be a topical composition that suppresses the aggregations generated based on hypromellose by containing a dihydric alcohol.

[0017] Other components may be appropriately selected and added to the above-mentioned external composition, as long as they do not impair the effects of the present invention. Examples include pharmacoactive ingredients, surfactants (nonionic surfactants, cationic surfactants, anionic surfactants, etc.), diluents, solubilizers, pH adjusters, viscosity adjusters, stabilizers, preservatives, fragrances, colorants, etc.

[0018] The above-mentioned external composition is suitably used as a pharmaceutical or cosmetic by incorporating medicinal ingredients such as pharmaceutical active ingredients or ingredients effective as cosmetics.

[0019] The above-mentioned active pharmaceutical ingredients are not particularly limited, but examples include heparinoids. The amount of heparinoid in the above-mentioned topical composition is preferably 0.01 to 5 wt%, and more preferably 0.1 to 0.3 wt%.

[0020] The pH of the above topical composition is preferably 5.5 to 7.0. By setting the pH within this range, the long-term stability of the topical composition can be improved, and skin irritation during use can be reduced. The pH can be adjusted as appropriate with a pH adjusting agent. Examples of pH adjusting agents for adjusting the pH of the topical composition to the above range include potassium dihydrogen phosphate, citric acid, sodium hydroxide, sodium lactate, sodium citrate, L-arginine, and diisopropanolamine.

[0021] The above external composition can be used by directly applying it to the skin, but it is preferably used in a foamed state. Therefore, the above external composition is preferably filled in a former container that can be foamed when discharged. Examples of the former container include a pump former container, a squeeze former container, and an aerosol container that fills the above external composition together with an aerosol agent, which are filled with the external composition as it is. Since the external composition of the present invention has improved high-temperature stability and the generation of gel-like aggregates and the like is suppressed, even when filled in a former container and used, clogging can be suppressed and it can be suitably used in a foamed state.

Examples

[0022] The present invention will be specifically described with reference to the following examples, but these examples do not limit the scope of the present invention.

[0023] External compositions were prepared by mixing each component in the amounts shown in Tables 1 to 3.

[0024]

Table 1

[0025]

Table 2

[0026]

Table 3

[0027] In addition, for the external compositions prepared in the examples and comparative examples, the pH was measured, and the appearance and foaming properties were evaluated as follows. The results are shown in Tables 1 to 3.

[0028] (Evaluation of appearance) Immediately after preparation and the external compositions stored overnight at 5°C, 40°C, 50°C, and 60°C were visually observed for appearance. The external appearance was assessed as follows: ○: No agglomeration of gels or other aggregates was observed. ×: The formation of aggregates such as gels was observed.

[0029] (Evaluation of foaming properties) The prepared topical composition was filled into a pump foamer container, and its foaming properties were evaluated when it was dispensed. The foaming properties were determined as follows. ○: Showed foaming properties ×: Did not exhibit foaming properties. [Industrial applicability]

[0030] According to the present invention, it is possible to provide an external composition with excellent high-temperature stability.

Claims

1. A topical composition comprising hypromellose, a dihydric alcohol, a heparin-like substance, and water, The dihydric alcohol comprises at least one selected from dipropylene glycol, propylene glycol, 1,3-butylene glycol, and pentylene glycol. The amount of the aforementioned dihydric alcohol is 9 wt% or more. The amount of hypromellose used is 0.02 to 0.8 wt%, The hypromellose has a degree of substitution of methoxy groups of 22.0 to 24.0% and a degree of substitution of hydroxypropoxy groups of 8.5 to 10.5%. It does not contain propellant. By containing the aforementioned dihydric alcohol, the formation of aggregates generated based on the hypromellose at 60°C is suppressed. When used, it forms foam, Filled into a foaming container other than an aerosol container, External composition.

2. The topical composition according to claim 1, wherein the dihydric alcohol is at least one selected from propylene glycol, 1,3-butylene glycol, and pentylene glycol.

3. The external composition according to claim 1 or 2, wherein the amount of water is 90 wt% or less.

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