topical skin preparations

Abstract

The present invention aims to provide an external skin preparation that improves skin firmness and has a silky smooth and pleasant feel when used in combination with specific ingredients. [Solution] The present invention provides an external skin preparation containing the following (A) to (C): (A) Almond extract (B) Pullulan (C) Cellulose nanofiber

Description

[Technical Field]

[0001] The present invention relates to an external preparation for skin. [Background technology]

[0002] Human skin can develop wrinkles and sagging due to aging and external stresses such as ultraviolet rays, and the degree of these conditions can increase. To alleviate these symptoms, technological developments have been made, such as combining various ingredients. For example, in Reference 1, an emulsion cosmetic that is excellent at giving skin firmness by combining stearyl stearate and hydrocarbons has been developed. However, it is difficult to achieve both effectiveness and a good feeling of use, and there is a need for the development of an external skin preparation that is satisfactory in both effectiveness and feeling of use. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-235472 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an external skin preparation that improves skin firmness and has a silky smooth and pleasant feel when used by combining specific ingredients. [Means for solving the problem]

[0005] The means for solving the problems of the present invention is to provide an external skin preparation containing the following (A) to (C): (A) Almond extract (B) Pullulan (C) Cellulose nanofiber [Effects of the Invention]

[0006] By using specific ingredients in combination, the topical skin preparation of the present invention exerts the effect of improving skin firmness and providing a silky smooth and pleasant feel when used. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described.

[0008] [Almond extract] The almonds in the almond extract (component (A)) used in the present invention are scientifically known as Prunus dulcis or Prunus amygdalus. The extract includes not only those extracted with a solvent, but also the original product and dried products. The parts to be extracted may be any part, such as leaves, flowers, seeds, or buds, and may be used as is or after processing such as crushing. When extracting with a solvent, the extraction method and solvent are not limited. Examples of extraction methods include immersion in an extracting solvent and supercritical extraction. Examples of extracting solvents that can be used include water, ethanol, propanol, isopropanol, 1,3-butylene glycol, propylene glycol, dipropylene glycol, glycerin, and mixtures thereof. Among these, seeds are preferred as the part to be extracted. Extraction with water is preferred as the extracting solvent.

[0009] The amount of almond extract in the present invention is not particularly limited to the total amount of the topical skin preparation, but is preferably 0.0001 to 5% by mass, more preferably 0.001 to 3% by mass. If the amount is less than 0.0001% by mass, sufficient effects may not be obtained, and if it exceeds 5% by mass, the skin may feel sticky.

[0010] [Pullulan] The component (B) pullulan used in the present invention is a water-soluble polymer having a structure in which maltotriose, in which three glucose molecules are linked by an α1-4 bond, is linked by an α1-6 bond. There are no particular limitations on the type of pullulan used, as long as it is one that is typically used in external skin preparations. Commercially available pullulan products include cosmetic pullulan, food additive pullulan (both manufactured by Hayashibara Biochemical Laboratories), and cosmetic pullulan (manufactured by Nagase Vita Co., Ltd.).

[0011] The amount of pullulan in the present invention is not particularly limited, but is 0.001% by mass to 1% by mass, more preferably 0.003% by mass to 0.5% by mass, and even more preferably 0.01% by mass to 0.2% by mass, based on the total amount of the topical skin preparation. If the amount is less than 0.001% by mass, sufficient effects may not be obtained, and if the amount is more than 1% by mass, the skin may feel sticky.

[0012] [Cellulose nanofiber] The cellulose nanofibers (component (C)) used in the present invention are not particularly limited as long as they are those typically incorporated into topical skin preparations. It is preferable to use cellulose nanofibers obtained by defibrating cellulose fibers to the nano level. Examples of the size of the cellulose nanofibers include fibrous substances with an average fiber width of 2 to 5 nm and a fiber length of 100 nm or more. In the present invention, the fiber width is preferably 10 nm or less, and more preferably 5 nm or less.

[0013] Examples of cellulose fibers include fibers separated from plant fibers such as plant-derived pulp, wood, cotton, hemp, bamboo, cotton, kenaf, hemp, jute, banana, coconut, cassava, seaweed, tea leaves, agricultural waste, and waste paper.

[0014] The cellulose nanofibers according to this embodiment include those made from plant-derived cellulose microfibrils (or their constituent fibers), as well as bacterial cellulose produced by microorganisms such as acetic acid bacteria, lignocellulose nanofibers, and cellulose nanofibers obtained by electrospinning. Lignocellulose nanofibers are cellulose nanofibers containing lignin (lignin-coated cellulose nanofibers). Cellulose nanofibers obtained by electrospinning are cellulose nanofibers obtained by spinning a solution of a cellulose-based material while applying a voltage.

[0015] The cellulose nanofibers according to this embodiment may be modified. The mode of modification can be selected depending on the purpose, and examples include hydrophobization and the introduction of functional groups. Specific modifications include acid modification [e.g., carboxylation (e.g., carboxymethylation), phosphorylation, sulfuric acid or sulfonation], ester or acyl modification (e.g., acetylation), amine modification, amide modification, epoxy modification, and fluorene modification. The acid group or amine group may form a salt.

[0016] Cellulose nanofibers can be obtained by mechanical defibration treatment. Preferably, before the defibration treatment, cellulose is oxidized using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxy radical) as a catalyst to introduce carboxyl groups (sodium carboxylate) onto the surface of the cellulose microfibrils. This preliminary treatment allows the cellulose to be defibrated into microfibril units by a milder mechanical defibration treatment, taking advantage of the repulsive force of the electric double layer.

[0017] Examples of commercially available cellulose nanofibers include Rheocrysta C-2SP (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and Cellenpia CS-01C (manufactured by Nippon Paper Industries Co., Ltd.).

[0018] The amount of cellulose nanofibers in the present invention is preferably 0.001 to 5% by mass, and more preferably 0.01 to 3% by mass, of the total amount of the topical skin preparation. If the amount is less than 0.001% by mass, sufficient effects may not be obtained, and if it exceeds 5% by mass, the skin preparation may feel sticky.

[0019] In addition to the above-mentioned components, the topical skin preparation of the present invention may contain optional components used in ordinary cosmetics and quasi-drugs to the extent that the effects of the present invention are not impaired. Specific examples include oils, surfactants, thickeners, preservatives, fragrances, moisturizers, antioxidants, anti-inflammatory agents, antibacterial agents, etc.

[0020] The formulation of the external skin preparation of the present invention is not particularly limited, and may be any formulation such as an oil-based formulation or an emulsion-based formulation.

[0021] The topical skin preparation of the present invention can be prepared by a conventional method.

[0022] The external skin preparation of the present invention can be used in the dosage form of, for example, a lotion, emulsion, or ointment. [Example]

[0023] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto. The blending amounts are in mass % unless otherwise specified.

[0024] [Elasticity (firmness) testing method] The samples shown in Table 1 were prepared and elasticity measurements were carried out.

[0025] [Measurement method] (1) Acclimation After washing the inside of the left and right forearms of the subjects, they wiped off the moisture and then rested for 15 minutes in a room adjusted to a temperature of 21±0.5°C and humidity of 50±5% to allow for acclimation. (2) Application A 3 cm x 3 cm area was marked on the inside of each forearm, and 7 mg of the sample was applied evenly with a finger wearing a finger cot. (3) Measurement Viscoelasticity was measured before and 30 minutes after application using a Cutometer MPA580 (manufactured by Courage+Khazaka). Skin viscoelasticity was measured using a Cutometer MPA580 probe with a 2mm suction port, applying 150mb suction pressure for 1 second, and then analyzing the skin displacement when the suction was released. In this study, a parameter (R7) used as an index of skin elasticity was analyzed. This is a value that indicates the "elastic recovery rate (how much the skin returns to its original state within a set time after suctioning for a certain period of time)," with a higher value indicating higher elasticity. The relative values, with the value before application set to 1, were calculated and are shown in Table 1.

[0026] [Usability evaluation] Nine sensory evaluators independently used the topical skin preparations of the Examples and Comparative Examples and evaluated them in terms of spreadability, penetration, body, adhesion, firmness, gloss, and softness of the skin according to the following criteria. The results are shown in Table 1. ◎: Very good ○:Good △: Bad ×: Very bad

[0027] [Slipperiness test method] The samples shown in Table 2 were prepared and the lubricity was measured.

[0028] [Measurement method] A 3 x 30 cm piece of artificial leather (Idemitsu Technofine Co., Ltd., 1 mm thick) was placed on the sample stage, and 5 mg of each sample was placed on a friction element (1 x 1 cm) wrapped with artificial leather (Idemitsu Technofine Co., Ltd., 1 mm thick). The average coefficient of friction (MIU) was measured using a friction tester (Kato Tech Co., Ltd., KES-SE). The measurement conditions were a movement speed of 1 mm / sec, a measurement distance of 20 mm, and a load of 50 g. A sample with a lower average coefficient of friction can be stretched and spread without resistance, resulting in a silky, smooth spread. 15 back-and-forth measurements were performed, and the average value was taken as the average coefficient of friction (MIU). The results are shown in Table 2.

[0029] [Table 1]

[0030] As shown in Table 1, it can be seen that the elasticity (firmness) is improved in Example 1 compared to before application. In addition, in each sensory evaluation, all scores were improved compared to Comparative Example 1, and it can be seen that Example 1 has a superior feel when used.

[0031] [Table 2]

[0032] As shown in Table 2, compared with the comparative examples, Example 1 has a reduced value of slipperiness, and it is clear that it has a silky and smooth slipperiness.

[0033] From the above, the topical skin preparation of the present invention improves skin firmness and has a silky smooth and pleasant feel when used.

Claims

[Claim 1] A topical skin preparation containing the following (A) to (C): (A) Almond extract (B) Pullulan (C) Cellulose nanofiber

Images