JPH0881348A - External preparation for skin - Google Patents

Abstract

PURPOSE: To obtain an external preparation for skin having both excellent moisture retention power and antiseptic power and low irritation to skin and good feeling in use. CONSTITUTION: This external preparation for skin contains >=20wt.% of trimethylglycine. Trimethylglycine in an amount of <=5wt.% can be replaced with a polyhydric alcohol in an amount of <=5wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a skin external preparation, and more particularly to a skin external preparation having an excellent moisturizing function and antiseptic property.

[0002]

2. Description of the Related Art An external preparation for skin is liable to be a nutrient source for microorganisms because it has a role of supplementing the action of skin secretions (sebum membranes), and thus the external preparation for growth is It may be a place.

The external preparation for skin contaminated with microorganisms causes deterioration in quality such as odor, deterioration and generation of mold, and it is necessary to take measures to prevent this. Therefore, it goes without saying that the manufacturing process is controlled hygienically, but most of the external preparations for the skin contain antiseptic / bactericidal agents for the purpose of antiseptic and sterilization.

[0004] In this regard, external preparations for skin (creams, emulsions, lotions, gels, etc.) whose purpose is to retain moisture.
In order to prevent the formulation itself from being contaminated with bacteria, phenoxyethanol, paraoxybenzoate, and photosensitizer / cation / phenol-based antiseptic / bactericidal agents have been added. It may be a cause.

Polyhydric alcohols are used as a component for both moisturizing and auxiliary preservative, but polyhydric alcohols such as propylene glycol, 1,3-butylene glycol and isoprene glycol are usually sufficient. Moisturizing and antiseptic properties are not obtained. On the other hand, when they are used alone in a concentration having an antiseptic effect, skin irritation is exhibited.

[0006] Glycerin has a moisturizing effect and has little anti-irritant effect even at a high concentration having antiseptic effect, but it has a problem in stickiness such as stickiness.

The present invention has been made in view of the above problems of the prior art, and its object is to have both excellent moisturizing power and antiseptic power and less irritation to the skin.
It is intended to provide an external preparation for skin having a good feeling in use.

[0008]

In order to achieve the above object, the gist of the present invention is to provide a skin external preparation characterized by containing 20% by weight or more of trimethylglycine as a first invention. A second invention is a skin external preparation characterized by using 5% by weight or less of polyhydric alcohol in place of 5% by weight or less of trimethylglycine.

Further, an anti-inflammatory component, a local anesthetic component, a blood flow promoting component, a whitening component and the like can be added depending on the purpose.

[0010]

[Function] Trimethylglycine is a natural substance safe to human body, which is contained in many plants such as sugar beet, shrimp, squid, etc., and is represented by the following structural formula.

[0011]

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As shown in the above formula, trimethylglycine is a zwitterionic moisturizer in which the amino group of glycine is trimethylated to form an inner salt, and its moisturizing effect is compared with other moisturizers. Is shown in FIG. In the figure, 1
Indicates trimethylglycine, 2 indicates glycerin, 3 indicates sorbit, 4 indicates sodium pyrrolidonecarboxylate. As a measurement condition, each moisturizer is prepared in a 50% aqueous solution, and the amount of residual water (%) is measured every day when the moisturizer is left in an atmosphere of a temperature of 30 ± 1 ° C and a relative humidity of 35 ± 3%. According to the method. As shown in the figure, the moisturizing power of trimethylglycine is extremely excellent.

The skin external preparation containing 20% by weight or more of trimethylglycine, which has an excellent moisturizing power, quickly penetrates into the keratinocyte layer to give the skin "moisture" and "smoothness" and an excellent antiseptic effect. Demonstrate. Even if 5% by weight or less of polyhydric alcohol is used instead of 5% by weight or less of trimethylglycine, antiseptic activity can be expected.

[0014]

Next, embodiments of the present invention will be described. Prescription No. compounded as shown in Table 1 below. The antibacterial properties of the compositions of (15) to (15) were tested.
Shown in The formulations in Table 1 are% by weight. The antibacterial test method was as follows.

[Test method for antibacterial property] (1) Preserved strain (Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa)
Thus, each bacterium was inoculated on a plate medium and cultured for 24 hours, and each bacterium thus obtained was dispersed in physiological saline and adjusted to about 10 ⁸ bacterial solution based on the turbidity.

(2) The exact concentration of the bacterial solution was determined from the number of colonies obtained by plating the diluted bacterial solution on a plate. The measurement results were 3 × 10 ⁸ cells / ml for E. coli, 6 × 10 ⁸ cells / ml for Staphylococcus aureus, and 3 × 10 ⁸ cells / ml for Pseudomonas aeruginosa.

(3) Next, the prescription No. 0.1 ml of each bacterial solution was inoculated to each 10 ml of the test sample of (15) (about 10 ml).
⁶ cells / ml) and cultured at 37 ° C.

(4) After 7 days and 14 days, 0.1 ml (diluted if necessary) of each test solution obtained as described above was plated, and the number of colonies was measured to check the change in the number of bacteria. I asked.

[0019]

[Table 1]

[0020]

[Table 2]

The following points are clear from Table 2. (a) Formulation N in which trimethylglycine is 15% by weight or less
o. There is no antiseptic effect in ~. Formulation No. in which trimethylglycine is 10% by weight. Prescription No., in which a small amount of methylparaben was added to the above. Some of them have some antiseptic properties, but they are not enough. Further, the prescription No. Formulation No. obtained by adding polyoxyethylene hydrogenated castor oil to No antiseptic effect is found in the thing.

(B) Prescription No. From the comparison between (10) and (10), it can be seen that trimethylglycine is an amphoteric substance, but its preservative power is not improved by weakly acidifying and cationizing.

(C) Prescription No. containing 20% by weight or more of trimethylglycine ,, (13), (14), (15) show a clear antiseptic effect.

(D) Prescription No. 20% by weight of trimethylglycine, 5% by weight was replaced with a polyhydric alcohol. (11) and (12) are prescription numbers. It has the same excellent antiseptic properties as.

(E) Recipe No. containing 20% by weight of trimethylglycine Formulation No. in which 5% by weight of polyhydric alcohol was added to (13) is the prescription number. It shows the above antiseptic power. As described above, the antiseptic power is enhanced by using the polyhydric alcohol together, but in consideration of the low irritancy, the addition amount of the polyhydric alcohol is preferably 5% by weight or less.

(F) Prescription No. And (14) or prescription N
o. As is clear from the comparison between (15) and (15), even if polyoxyethylene hydrogenated castor oil, which is a nonionic activator, is added, preservative power does not decrease at all because it has a sufficient amount of trimethylglycine. .

[0027]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, it has excellent antiseptic power and moisturizing power, less irritation to the skin, and good usability. Further, by using trimethylglycine and a polyhydric alcohol in combination, the antiseptic effect can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing the moisturizing effect of various moisturizers.

Claims (2)

[Claims] 1. A skin external preparation containing 20% by weight or more of trimethylglycine. 2. The external preparation for skin according to claim 1, wherein 5% by weight or less of polyhydric alcohol is used in place of 5% by weight or less of trimethylglycine.