CN1165281C - Sunscreen composition - Google Patents

Abstract

A topical cosmetic sunscreen composition comprising (i) from 0.1 to 10% by weight of the composition of an ultra-violet radiation absorbing sunscreen dissolved in an oil; and (ii) a cosmetically acceptable vehicle. A process for preparing such a composition is also described. The inventive composition has improved sunscreen efficacy.

Description

Sunscreen composition

Affiliated field

The present invention relates to improved beauty treatment sunscreen composition and preparation method thereof, said composition can be used for human body skin in the part, to strengthen the Exposure to Sunlight protective action.

Background technology

Melanin is to act on aminoacid one tyrosine and synthetic black pigment by tryrosinase.This reaction betides and is called in the organelle contained in the melanocytic cell (being called melanosome).Melanocyte will contain melanic melanosome and be transferred in the adjacent horn cell, and organelle stays in this and comes off from human body through the skin top layer until itself.The degree of depth of skin color and the number of melanosome, granularity, melanin content, formation and the speed that shifts in horn cell are directly related.Because melanin can absorb incident ultraviolet, so it still is skin and hypodermic important protection material.

Ultraviolet ray range can be divided into three zones, wavelength is about the UV-A of 320-400nm, and it has tanning effects and can not cause inflammation; Wavelength is about the UV-B of 290-320nm, can produce erythema (sunburn) reaction and cause tanned at last; And wavelength is about the UV-C of 200-290nm, its general can absorption by the ozone layer of earth atmosphere, but meeting extreme injured skin.

The melanocyte generation of skin and pigmentation and its reaction to irradiation under ultraviolet ray are closely related.Photobiology changes the erythema that causes and also can cause melanocyte to form and the pigmentation increase.Therefore contacting daylight can cause skin darkening, and it reaches by direct pigment melanism of established melanin and new melanic formation.Made many skin compositions already and be used to keep the colour of skin, avoided tanned after making it and ultraviolet light contacting.These compositionss all cause the extraneous ultraviolet light of damage and meeting tanning maybe can absorb the composition of this class ultraviolet light based on reflecting with the scattering meeting.

For preventing already present melanin melanism and new melanin formation in the skin, the scope of skin protection is about the UV-A of wavelength 320-400nm.We find, can protect skin by careful selection sunscreen, make it avoid radiation melanism result.

GB 1370236 discloses a kind of skin whitening composition that contains nicotinic acid, and the method that realizes its skin whitening effect by melanic dispersion or distribution in the obstruction epidermis.

GB 1533119 discloses the rubescent reaction that nicotiamide can be used as skin whitener and don't can cause the normal skin relevant with nicotinic acid to cause because of vasodilation.

GB 2230186 discloses in the compositions that contains sunscreen and nicotiamide mixture and has added polysiloxane compound, can improve the coverage of protectiving ultraviolet cream frost on skin.

After the applicant's discovery was dissolved in oil phase with sunscreen, this compositions that contains sunscreen can be promoted skin to Ultraviolet rays protection.Say that more specifically the applicant finds, adopts the sunscreen that is dissolved in oil phase can improve sun-proof usefulness, make it surpass the sun-proof usefulness that does not adopt this scheme and adopt a large amount sunscreen more to be reached.The present invention can make and reach the required sunscreen consumption reduction of identical ultraviolet radiation protective effect thus.

Therefore, the invention provides a kind of locally with the beauty treatment sunscreen composition, wherein contain: what (i) account for compositions 0.1-10% (weight) is dissolved in pick up the oil ultraviolet sunscreen; (ii) be applicable to the carrier of cosmetics.Said composition preferably makes through following method provided by the invention.

The present invention also provides a kind of method of sunscreen composition of improving looks that is used to prepare, and comprising following steps: (i) the absorption ultraviolet sunscreen that will account for compositions 0.1-10% (weight) is dissolved in oil phase; (ii) in aqueous phase and stearic acid; And (iii) with dissolved sunscreen with through neutral stearic acid and be applicable to that the carrier of cosmetics homogenizes.

Dissolved sunscreen can be earlier with through neutral stearic acid homogenizing, and then mix with combination carrier (or other compositions).But preferably will together mix through neutral stearic acid and carrier earlier, in mixture, add sunscreen then, and find to make compositions have best sun-proof result thus.

Preferred stearic acid is to use alkali metal, neutralizes as potassium hydroxide.Preferably stearic acid is being higher than before (ii) fusion under 70 ℃ the temperature in step.

Sunscreen be preferably selected from the 4-tert-butyl group-4 '-available from Givaudan, methoxy cinnamic acid 2-Octyl Nitrite is with the mixture of trade name PARSOL MCX available from Givaudan or these two kinds of sun screening compounds with trade (brand) name PARSOL 1789 for methoxy dibenzoyl methane.Said composition contains the sun screening compound that accounts for compositions 0.1-10% (weight), preferred 0.1-5% (weight).

Oil can be the oil in mineral oil, vegetable oil or other sources, but preferably it is in a liquid state being higher than under 20 ℃ the temperature.Oil can be selected from mineral oil, Oleum Arachidis hypogaeae semen, Oleum Helianthi, safflower oil, Oleum sesami or their mixture.But when adopting method for optimizing, with sunscreen be dissolved in oil phase, and subsequently it to be added aqueous phase blended in neutral stearic acid and carrier the time, then should oil not necessarily be in a liquid state being higher than under 20 ℃.The oil that is suitable under this situation comprises isopropyl myristate.

In a specific embodiments, elder generation 70 ℃ of following fusions, then with the potassium hydroxide aqueous solution neutralization, is cooled to back below 50 ℃ to wherein adding the sunscreen that is dissolved in oil phase with emulsified body with stearic acid.This emulsified body constitutes the substrate of every other composition.Then can be with other compositions and the common homogenizing of this substrate.In preferred embodiments, these other compositions can be mixed with stearic acid/water earlier, and then with the common homogenizing of sunscreen/oil phase.

Can randomly contain 0.1-10% (weight) in the present composition, preferred one or more skin whiteners of 0.5-5% (weight).Skin whitener is preferably selected from: nicotinic acid, nicotiamide or its can discharge the precursor of nicotiamide to skin.Nicotiamide is the amide of nicotinic acid, and it is also referred to as niacin amide or pyridine-3-carboxylic acid.The example of nicotiamide precursor compound is a nicotinamide ascorbate.Other skin whiteners that are suitable for comprise: intacellin, hydroquinone and derivant thereof (for example arbutin), kojic acid, dicarboxylic acids (Azelaic Acid, decanedioic acid), it is respectively suc as formula HOOC-(C _xH _yShown in the)-COOH, wherein x=4-20, and y=6-40, ascorbic acid and derivant thereof, hydroxy acid (lactic acid, glycolic, malic acid, tartaric acid etc.), ferulic acid, retinol and derivant, perhaps other known skin whitening chemical compounds.

The carrier that constitutes this cosmetic composition is one or more and sunscreen and the compatible material of brightening agent that may exist, and it can not injure skin.Carrier can be used as diluent, dispersant or the carrier of other compositions in the compositions, should guarantee that therefore these compositions are easy to evenly coating and distribution on skin with suitable concentration.

The carrier that is applicable to the present composition can comprise: water, powdered absorbent, binding agent and carrier, and liquid, and as emollient, propellant, solvent, wetting agent and thickening agent.

Compositions of the present invention can be made into the dosage form of the product type commonly used that is suitable for the local skin application, as cream frost, emulsion, ointment and aerosol product.

Adopt following examples to further specify the present invention.

Embodiment

Embodiment 1:

The method for preparing the present composition:

In main blender, 60g water and 0.48g potassium hydroxide are heated to 70 ℃.In inferior container, 16g stearic acid, 4.4g isopropyl palmitate, 0.15g propyl p-hydroxybenzoate are heated to 70 ℃, and add and become owner of uniform mixing in the blender.Add composition, for example nicotiamide, essence, water and uniform mixing commonly used therein.This mixture is cooled to 30 ℃, will be dissolved in the 0.4g Parsol 1789 of 2g mineral oil and the remainder of 1.2g Parsol MCX and preparation and homogenizes.

Conventional method:

In main blender, add 60g water and 0.48g potassium hydroxide.In inferior blender, mix 16g stearic acid, 0.15g propyl p-hydroxybenzoate, 0.2g polysiloxanes and 4.4g isopropyl palmitate and be heated to 70 ℃, and 0.4g Parsol 1789 and 1.2g Parsol MCX are dissolved in the part of this mixture.Stir down two mixture to be added and become owner of in the blender, and uniform mixing.For example nicotiamide, essence, water mix to 100g to add other compositions commonly used.

Embodiment 2:

Sunscreen sprawling and carrying on skin:

Clean 15 volunteers' forearm with soap, and pat dry this surface, coating cream frost is to guarantee that forearm is fully with evenly dry after half an hour.

Use template labelling 2cm * 3cm area respectively.With Glass rod coating 30mg cream frost, it is only sprawled in the labelling inboard fully carefully.Adopt respectively from pharmacists's cellophane tape and get the marking, fully carefully to prevent to besmirch measured surface in tested zone.Adhesive tape is put on the framework.Carry out following different disposal.

Embodiment 2a: the cream frost (placebo) that does not contain sunscreen or nicotiamide

Embodiment 2b: through the cream frost (sunscreen wherein contains the Parsol MCX of the Parsol 1789 and 1.2% (weight) that accounts for compositions 0.4%) of above-mentioned conventional method preparation, the content of nicotiamide is 1.0%.

Embodiment 2c: the cream frost for preparing among the embodiment 2b, but wherein contain the sunscreen (accounting for the Parsol MCX of the Parsol 1789 and 2.4% (weight) of compositions 0.8%) and 2.0% nicotiamide of doubling dose.

Embodiment 2d:, wherein add the sunscreen (accounting for the Parsol MCX of the Parsol 1789 and 1.2% (weight) of compositions 0.4%) that is dissolved in mineral oil by the cream frost of method for preparing of the present invention.Add 1.0% nicotiamide.

Measure the uniformity of sprawling of cream frost:

The framework that will have adhesive tape places ultraviolet source, and the tacky surfaces that makes adhesive tape down.Ultraviolet filter is placed on the light source to guarantee that producing wavelength is the ultraviolet that 240-350nm has constant intensity.1: 1 glycerol from taking-up 2% between two cover strips: the thin film of the uniform fluorescent dye CBS-X of aqueous solution form also places adhesive tape not have the one side of glue, the absorption maximum optical wavelength of described fluorescent dye CBS-X is 368nm, and the emission maximum optical wavelength is 406 and 426nm.The television camera record that has low power enlarging lens (6 times) that this can be adopted in the time of can making as being transmitted in transmission and crossing adhesive tape of the visible light in ultraviolet source.

Thus, have the position ultraviolet light capable of blocking of sunscreen, fluorescent agent can not be excited, thereby obtains black region.Television camera links to each other with the computer that has the figure capture card, and picture can be stored in the computer.Adopt the Optimas image analysis software, it can carry out quantitative analysis to the difference that the ultraviolet amount of adhesive tape is crossed in transmission.Intensity is low more, and the ultraviolet barrier is good more, and then sun-proof usefulness is good more.In addition, adopt advanced image analysis technology enlarged photograph and measure intensity, adopt specific UVA and UVB detector also can measure the actual transmission amount of UVA and UVB.

Table 1 shows that the sun-proof usefulness of the prepared preparation according to the present invention is higher than the cream frost of preparation according to conventional methods, and suitable with preparation, that contain the preparation that doubles the consumption sunscreen according to conventional methods sun-proof effect.

Table 1

Embodiment	Intensity	UVA	UVB
				2a	54.17	0.25	0.21
2b	43.62	0.15	0.08
				2c	23.06	0.08	0.02
2d	32.46	0.10	0.03

Embodiment 3

Skin of living body brighten data:

Select 20 volunteers, respectively twice of every day be at the prepared cream frost (2d) of its forearm coating 0.75g the present invention, or the cream frost of (2b) preparation according to conventional methods, or placebo (2a).The opposite side forearm is as the matched group of uncoated.By 10 minutes the colour of skin was assessed for 8 weeks in coating the previous day and coating back.The data of table 2 are variations of 8 week of coating back score value.Negative shows that the colour of skin is compared with matched group and bleaches, and positive number shows compares colour of skin blackening with matched group.

Table 2

Embodiment	Mark
		2a	+0.04
2b	-0.42
		2d	-0.54

Embodiment 4

Following cream frost is used for skin whitening double blinding clinical trial.Select 20 volunteers, twice of every day coating 0.75g the foregoing description 1 on its forearm the prepared cream frost of the present invention, but wherein adopt 2% isopropyl myristate (and non-mineral oil) as oil phase (3a), or the cream frost (2b) for preparing according to conventional methods, the opposite side forearm is as the matched group of uncoated.By 10 minutes the colour of skin was assessed for 8 weeks in coating the previous day and coating back.The data of table 3 are variations of 8 week of coating back score value.Negative shows that the colour of skin is compared with matched group and bleaches, and positive number shows compares colour of skin blackening with matched group.

Table 3

Test 1 test 2

2b	0.46	-0.30
			3a	-0.51	-0.39

Claims (5)

1. method for preparing sunscreen composition, comprising following steps:

(i) the absorption ultraviolet sunscreen that will account for compositions 0.1-10 weight % is dissolved in oil phase;

(ii) in aqueous phase and stearic acid; And

(iii) with dissolved sunscreen with through neutral stearic acid and be applicable to that the carrier of cosmetics homogenizes.

2. the described method of claim 1, wherein dissolved sunscreen are after neutral stearic acid and the carrier that is applicable to cosmetics are homogenized, again with through neutral stearic acid be applicable to that the carrier of cosmetics homogenizes.

3. the described method of arbitrary claim in the claim 1 or 2 is comprising following additional step: be higher than before (ii) in step under 70 ℃ the temperature the stearic acid fusion.

4. the described method of arbitrary claim in the claim 1 or 2, wherein oil phase is an isopropyl myristate.

5. the part that makes according to the described method of claim 1 is with the beauty treatment sunscreen composition.