EP0876138A1

EP0876138A1 - Oil-containing soap gel preparation

Info

Publication number: EP0876138A1
Application number: EP97902190A
Authority: EP
Inventors: Bernhard Banowski; Marion Zinken
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1996-01-27
Filing date: 1997-01-20
Publication date: 1998-11-11
Also published as: DE19602902A1; WO1997026859A1

Abstract

The invention concerns a soap gel preparation for the use of cosmetic or pharmaceutical active substances, in particular in stick form, containing between 5 and 15 wt % fatty acids in the form of their alkali soaps, between 20 and 50 wt % of a water-soluble polyol, and between 30 and 70 wt % water, said preparation also comprising a portion of between 1 and 10 wt % of a water-insoluble oil in the form of an emulsion with a droplet size of less than 500 nm. The oil is transformed into a transparent microemulsion or an opalescent PIT emulsion and thus incorporated into the molten soap gel stick mass. Oils particularly suitable for this purpose are hydrocarbon oils, dialkylether with between 14 and 36 carbon atoms or mixtures of these substances with a fatty acid ester.

Description

Oil-based soap gel preparation

The invention relates to a shaped preparation for the use of cosmetic and pharmaceutical active ingredients, in particular in stick form, based on a soap gel which has good dimensional stability and contains a water-insoluble, homogeneously incorporated cosmetic oil and largely of lower alcohols free is.

Soap geese have long been known as carriers for topical cosmetic and pharmaceutical agents. Sodium stearate gels in aqueous lower alcohols and glycols are usually used as soaps. In recent years, attempts have been made to reduce the content of lower alcohols or to replace them entirely with glycols and polyols. In addition, such sticks are tried to incorporate skin-softening or refatting components. This leads to inhomogeneity and separation in the known water-insoluble oil components. Therefore, water-soluble or water-dispersible emollients have always been used, e.g. according to EP-A 450 597 the alkylene oxide adducts with fatty alcohols. However, these products do not have sufficient cosmetic and skin-care effects.

The stable incorporation of fragrance oils can also impair the transparency of the soap gels. EP-A 499 304 therefore proposed the use of very specific fragrances. It has now been found a way to incorporate water-insoluble oils in substantial quantities in a stable and homogeneous manner in soap gel preparations. The invention therefore relates to a soap gel preparation for the topical use of cosmetic and pharmaceutical active ingredients, in particular in stick form, with a content of

5 - 15% by weight of fatty acids with 14 - 22 C atoms in the form of their alkali soap 20 - 50% by weight of a polyol with 2 - 6 C atoms and 2 - 6 hydroxyl groups 30 - 70% by weight of water, characterized in that that

1 - 10% by weight of a water-insoluble oil in the form of an emulsion with a droplet size below 500 nm.

The seduction of water-insoluble oils in fine-particle emulsions, e.g. in microemulsions with droplet sizes below 100 nm or in opalescent so-called PIT emulsions with particle sizes from 100 to 300 nm using the phase inversion method are state of the art. For example, from Progr. Colloid & Polymer Sei 73 (1987), 37-47, how to produce extremely finely divided oil-in-water emulsions with the aid of a combination of nonionic emulsifiers and coemulsifiers from hydrocarbon oils. DE-A 38 13 193 proposes an emulsifier system which enables the production of such emulsions even with polar oils of the fatty acid ester type. Although such PIT emulsions predominantly contain emulsion droplets of a size below 300 nm, fractions of up to 10% by weight of the oil component in a droplet size of 300 to 500 nm can be present. A method for producing microemulsions are e.g. known from DE-A 44 11 557 and DE-A 44 17476.

All water-insoluble, skin-compatible oils and fatty substances and their mixtures with solid paraffins and waxes are suitable as oil components. However, the melting point of the mixtures with solid paraffins and waxes which may be used should, if possible, be below the phase inversion range of the emulsion and preferably below 40.degree.

Suitable skin components which are compatible with the skin are preferably hydrocarbons which are still liquid at 20 ° C., for example paraffin oils and synthetic hydrocarbons such as 1,3-di- (2- ethyl hexyl) cyclohexane (Cetiol * S). Another particularly suitable oil component are the di-n-alkyl ethers such as di-n-octyl ether, di (2-ethylhexyl) ether, lauryl methyl ether or octyl butyl ether.

In a preferred embodiment, in the soap gel preparations according to the invention, hydrocarbon oils, dialkyl ethers with 14-36 C atoms or mixtures of these components with a fatty acid ester are used as water-insoluble oil, e.g. contain with a caprylic / capric acid triglyceride.

A particularly diverse group of cosmetic oil components is that of the fatty acid and fatty alcohol esters, for example isopropyl myristate, n-butyl stearate, 2-ethylhexyl caprylate, cetyl oleate, glycerol tricaprylate, coconut fatty alcohol (Ci ₂ -Cιg) caprylate / caprinate and other. Also suitable are naturally occurring ester oils such as jojoba oil or liquid vegetable triglyceride oils such as olive oil, sunflower oil, soybean oil, rapeseed oil, almond oil, the liquid fractions of coconut oil or beef tallow and synthetic triglceride oils.

Suitable dicarboxylic acid esters are e.g. Di-n-butyl adipate, di-n-butyl sebacate, di- (2-ethylhexyl) adipate, di- (2-hexyldecyl) succinate and di-isotridecyl acelaate. Suitable diol esters (HI) are e.g. Ethylene glycol dioleate, ethylene glycol di-isotridecanoate, propylene glycol di- (2-ethylhexanoate), propylene glycol di-isostearate, propylene glycol di-pelargonate, butanediol di-isostearate and neopentyl glycol di-caprylate.

In a mixture with these liquid oil components, semi-solid and solid paraffins and waxes as well as solid triglyceride fats can also be used in smaller quantities.

As emulsifiers, the PIT emulsions contain a combination of a hydrophilic, nonionic emulsifier with an HLB value of preferably 10-15 and a lipophilic coemulsifier. The HLB value should be understood to mean a quantity that can be calculated from the structure of the emulsifier according to HLB = I °° - ^L

5

where L is the weight fraction (in%) of the lipophilic groups, e.g. is the fatty alkyl or fatty tacyl groups in the emulsifier.

The hydrophilic emulsifiers are preferably ethylene oxide adducts on fatty alcohols with 16-22 C atoms or on partial esters of polyols with 3-6 C atoms and fatty acids with 14-22 C atoms. However, ethylene oxide addition products on fatty acids, on alkyl glucosides, on methyl glucoside fatty acid esters, on fatty acid alkanolamides, on fatty acid glucamides and other fatty substances with ethoxylatable substituents are also suitable. Particularly preferred hydrophilic emulsifiers are alkyl polyglycosides of the formula RO - (Z) _χ , in which R is a C 1 -C ₂ -alkyl or alkenyl radical,

Z is a monosaccharide, in particular glucose, and x whose degree of oligomerization is a number from 1 to 5, in particular from 1.2 to 1.4.

The lipophilic co-emulsifiers are preferably saturated fatty alcohols with 16-22 C atoms, partial esters of polyols with 3-6 C atoms with saturated fatty acids with 14-22 C atoms, free fatty acids with 16-22 C atoms Atoms, to glycol monofatty acid esters, to fatty acid alkanolamides from C ₂ -C -g fatty acids with mono- or dialkanolamines with 2-4 C atoms in the alkanol group or to glycerol mono-fatty alcohol ethers.

Suitable fatty acids for the preparation of the soap gel preparations according to the invention are, for example, palmitic acid, stearic acid, arachic acid, behenic acid or technical mixtures which consist largely of such fatty acids, for example hardened palm oil fatty acid or hardened tallow fatty acid. Stearic acid is preferably used. To increase the abrasion on the skin, it can be very advantageous to replace some of the saturated, linear fatty acids mentioned by branched-chain fatty acids, such as 2-hexyldecanoic acid, 2-octylidodecanoic acid or isostearic acid. Such an addition of branched-chain fatty acids ensures that the soap gel preparations are range below 35 ° C have good strength, but melt immediately upon contact with the skin and become slippery, so that a thin film of the preparation spreads easily on the skin.

All or most of the fatty acids are present as alkali salts (alkali soaps), preferably as sodium soap. Other neutralizing agents, e.g. Triethanolamine can be used. However, a small proportion of free unsaponified fatty acid, for example in an amount of 0.01 to 0.5% by weight of the preparation, is not disadvantageous.

As polyols with 2-6 carbon atoms and 2-6 hydroxyl groups e.g. Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, glycerol, erythritol, pentaerythritol, trimethylol propane, sorbitol, methyl glucoside, cyclohexanetriol, inositol become. Propylene glycols and glycerol alone or mixtures of these polyols with sorbitol and or butylene glycol are preferred. These polyols are preferably contained in a total amount of 20-50% by weight of the soap gel preparation. These polyols can also be partially replaced by polyethylene glycols.

The soap gel preparations according to the invention are preferably free of lower alcohols. However, it is optionally possible to use up to 10% by weight of lower alcohols such as e.g. Use ethanol or isopropanol instead of the polyols mentioned.

The soap gel preparations according to the invention serve the topical application of cosmetic and pharmaceutical active ingredients. Depending on the dosage required for the specific application, such active ingredients are incorporated into the soap gel preparation. Cosmetic active ingredients include, for example, antimicrobial, deodorant, skin-moisturizing, antiperspirant, depilating, coloring and fragrant substances and cosmetic oils. Examples of pharmacological active substances are antibiotics, corticosteroids, local anesthetics and other active substances which are used against skin diseases. The amount of cosmetic or pharmaceutical active ingredients will generally be in the order of 0.1-5% by weight of the preparation, preferably in a range of 0.1-1% by weight of the preparation. A particularly preferred area of application for the soap gel preparations according to the invention is that of deodorant sticks. According to the invention, such products contain deodorising substances as cosmetic active ingredients. Suitable deodorant active ingredients are, for example, antimicrobial substances such as, for example, 2,4,4'-trichloro-2 ^, hydroxydiphenyl ether (Irgasan DP300), chlorhexidine digluconate or phenoxyethanol, deodorant, antimicrobial essential oils, farnesol, lipase-inhibiting substances such as triethyl citrate, astringent substances such as As sodium aluminum chlorohydroxy lactate and other known body deodorants or antiperspirants.

In a preferred embodiment, an antimicrobial or esterase-inhibiting deodorant active ingredient or an astringent antiperspirant active ingredient is contained in the soap gel preparation according to the invention in an amount of 0.1-10% by weight.

In addition to the active substances mentioned, the soap gel preparations according to the invention can contain further auxiliaries which are useful for improving the appearance and storage stability. Such tools are e.g. Complexing agents, antioxidants, preservatives, fragrances, colorants, opacifiers, pearlescent pigments, water-soluble salts such as e.g. NaCl or finely divided, fumed silica.

The preparation of the soap gel preparations according to the invention is expediently carried out by mixing polyols, water and fatty acid mixtures in a container with heating to about 50-90 ° C., adding the alkali metal hydroxide in the form of a concentrated aqueous solution and the mass moved until the saponification of the fatty acids is complete with the formation of a clear solution. Then the active ingredients, the auxiliary agents] and the finely divided emulsion of the water-insoluble oil can be mixed in one after the other during the cooling. Finally, the mass is molded into a mold, e.g. poured into a pin sleeve and allowed to cool there to a temperature at which the mass solidifies to form a stable gel.

A further subject of the patent is therefore the process for the preparation of the soap gel preparation according to the invention, which consists in that the water-insoluble oil is mixed into a transparent microemulsion or into an opalescent PIT by known processes. Transferred emulsion with a particle size below 300 nm and this emulsion mixed into the molten soap gel stick mass and then allowed to solidify.

The following examples are intended to explain the subject of the invention in more detail:

B e i s p i e l e

Preparation of the PIT emulsion

3 parts by weight of l, 3-di- (2-ethylhexyl) cyclohexane (Cetiol * S) 1 part by weight of Cg / Cio fatty acid triglyceride (Myritol * 318) 1.2 parts by weight of an emulsifier mixture consisting of

40% by weight cetyI / stearyl alcohol + 20 mol EO

37.5% by weight glycerol monostearate

7.5% by weight cetyl stearyl alcohol + 12 mol EO

7.5% by weight of cetyl stearyl alcohol

7.5% by weight of cetyl palmitate were heated to and at a temperature of 95 ° C. with 6 parts by weight of water

Temperature converted into a fine emulsion, which after cooling

Room temperature has a slightly cloudy to opalescent appearance.

Manufacture of soap gel pens

6 parts by weight of stearic acid

10 parts by weight of 1,2-propylene glycol and

20 parts by weight of glycerin

50 parts by weight of water were mixed and heated to 70 ° C. 2 parts by weight of NaOH solution (45% strength) were added in portions to this mixture, the mixture becoming homogeneous with hydrolysis. Then, 0.2 parts by weight of Irgasan ^® were mixed DP500 (2,4,4'-trichloro-2'-hydroxydiρhenylether) and 1 part by weight of perfume oil. Finally were

11 parts by weight of the previously prepared PIT emulsion, which had a temperature of 70 ° C, mixed. Then the mass was poured into pin sleeves and cooled to + 20 ° C. Thereby dimensionally stable, homogeneous soap gel sticks with a content of nourishing cosmetic oils were obtained.

Comparison test:

If 10 parts by weight of a mixture of 6 parts by weight of glycerol, 3 parts by weight of emulsifier (cetylstearyl alcohol + 30 mol EO) and 1% by weight of sodium chloride were added instead of the PIT emulsion, a dimensionally stable, homogeneous stick was likewise obtained. However, the attempt to add 2 parts by weight of one of the oil components or a mixture of the oil components (Cetiol S and / or Myritol 318) led to unsightly, inhomogeneous compositions.

Claims

claims

1. Soap gel preparation for the topical application of cosmetic and pharmaceutical active ingredients, in particular in stick form, with a content of

5 - 15% by weight of fatty acids with 14 - 22 C atoms in the form of their alkali soap 20 - 50% by weight of a polyol with 2 - 6 C atoms and 2 - 6 hydroxyl groups 30 - 70% by weight of water characterized in that

1-10% by weight of a water-insoluble oil is contained in the form of an emulsion with a droplet size below 500 nm.

2. soap gel preparation according to claim 1, characterized in that an antimicrobial or lipase-inhibiting deodorant active ingredient or

Antiperspirant active ingredient is contained in an amount of 0.1 to 10 wt .-%.

3. soap gel preparation according to claim 1 or 2, characterized in that as polyols glycerol and / or propylene glycol or mixtures of these substances with sorbitol and / or 1,4-butylene glycol are included.

4. soap gel preparation according to claim 1 to 3, characterized in that a hydrocarbon oil, a dialkyl ether having 14-36 carbon atoms or a mixture of these components with a fatty acid ester is contained as the water-insoluble oil.

5. A process for the preparation of a soap gel preparation according to claims 1 to 4, characterized in that the water-insoluble oil is converted according to known processes into a transparent microemulsion or into an opalescent PIT emulsion with a particle size below 500 nm and the Mix the emulsion into the molten soap gel stick mass and then allow the mass to solidify.