CA2232422A1 - The use of cationic biopolymers for the production of antidandruff formulations - Google Patents

Abstract

Proposed is the use of cationic biopolymers, especially of the chitosan type, as active substances to produce anti-dandruff agents and to destroy yeasts.

Description

The Use of Cationic Biopolymers for the Production of Antidandruff Formulations Field of the Invention This invention relates to the use of cationic biopolymers for the production of antidandruff formulations and for destroying yeasts.

Prior Art "Scales" is the colloquial terrn for those parts of the horny layer of the skin which are shed during the constant renewal of the skin layers. On the hair-covered head, scales are clearly visible as a result of amalgamation by tallow and perspiration into relatively large aggregates. Cosmetically unattractive squamation of the scalp, which can be caused by a number of pathological yeasts and which is generally accompanied by more or less intensive itching, has hitherto been tackled by treatment with antidandruff shampoos containing, for example, selenium compounds, pyrithione salts or glucocorticosteroids as ingredients (cf. S. Shuster in Br. J. Dermatol., 111, 235 (1984) and Cosmet. Toil.,103, 87 (1988).
Now, neither selenium nor pyrithione salts are among the more dermatologicallycompatible ingredients of hair treatment formulations. More specifically, this means that they have a certain sensitizing potential and, because of this, can cause irritation in particularly sensitive users. On account of the danger of side effects, glucocorticosteroids are only used in cases where squamation has been aggravated by illness. Accordingly, the problem addressed by the present invention was to provide new active ingredients for antidandruff formulations which would act against yeasts, would reduce scaling of the scalp and at the same time would show improved dermatological compatibility.

Description of the Invention The present invention relates to the use of cationic biopolymers, more particularly chitosans, for the production of antidandruff formulations.
It has surprisingly been found that, even in very small quantities, the polymers reduce suspensions of various yeasts to germ contents below 1 0/g in four hours. Accordingly, when the polymer solutions are applied to the scalp, i.e. for example where they form part of a hair treatment formulation, squamation can be significantly reduced. The invention includes the observation that, in addition, cationic biopolymers and especially chitosans show particularly high dermatological compatibility which makes them suitable for use on the scalp.

Cationic biopolymers Cationic biopolymers, such as chitosans for example, belong to the group of hydrocolloids. Chemically, they are generally partly deacetylated chitins - or derivatives thereof - varying in molecularweight which contain the idealized monomer unit (I):

(I) In contrast to most hydrocolloids, which are negatively charged at biological pH values, chitosans and their derivatives are cationic compounds under these conditions. The positively charged biopolymers are capable of interacting with oppositely charged surfaces and, accordingly, are used in cosmetic hair-care and body-care formulations and also as thickeners in amphoteric/cationic surfactant mixtures. Reviews on this subject have been published, for example, by B. Gesslein et al. in HAPPI 27, 57 (1990), by O.
Skaugrud in Drug Cosm. Ind. 148, 24 (1991) and by E. Onsoyen et al. in Seifen-Ole-Fette-Wachse 117, 633 (1991). Chitosans are produced from chitin, preferablyfrom the shell remains of crustaceanswhich are available in large quantities as inexpensive raw materials. Normally, the chitin is first deproteinized by addition of bases, demineralized by addition of mineral acids and, finally, deacetylated by addition of strong bases, the molecularweights being spread over a broad range. Corresponding processes for the production of - microcrystalline - chitosan are described, for example, in WO
91/05808 (Firextra Oy) and in EP-B1 0 382 150 (Hoechst). Besides cationic biopolymers of the chitosan type, derivatives, especially hydroxypropyl chitosans, may also be used as starting materials for the production of the antidandruffformulations. The quantities used may be in the range from 0.01 to 3% by weight and are preferably in the range from 0.05 to 1% by weight and more preferably in the range from 0.1 to 0.5% by weight, based on the formulation.

Commercial Applications The cationic biopolymers are not only particularly compatible with the skin, they also kill off the yeasts responsible for the excessive formation of head scales such as, for example, Candida albicans or Mallassezia fuffur (which was previously known by the name of Pityrosporum ovale) both quickly and reliably. Accordingly, they are particularly advantageous active substances for the production of antidandruff formulations. Another claim relates to their use for the destruction of yeasts. This also includes occlusiveapplication on the skin or mucous membrane, for example for treating thrush.

Antidandruff formulations The antidandruffformulations may contain surfactants compatible with their other ingredients. Typical examples are fatty alcohol polyglycol ether sulfates, monoglyceride sulfates, mono- and/or dialkyl sulfosuccinates, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, ether carboxylic acids, alkyl oligoglucosides, fatty acid glucamides, alkyl amidobetaines and/or vegetable protein fatty acid condensates.
The formulations, which are preferably shampoos or conditioners, may also contain oils, emulsifiers, superfatting agents, thickeners, cationic polymers, silicone compounds, biogenic agents, film formers, preservatives, dyes and fragrances as further auxiliaries and additives.
Suitable oils are, for example, Guerbet alcohols based on fatty alcohols containing 6 to 18 and preferably 8 to 10 carbon atoms, esters of linear C6 20 fatty acids with linear C6.20 fatty alcohols, esters of branched C6 ,3 carboxylic acids with linear C6 20 fatty alcohols, esters of linear C6 ,8 fatty acids with branched alcohols, more particularly 2-ethyl hexanol, esters of linear and/or branched fatty acids with polyhydric alcohols (for example dimer diol or trimer diol) and/or Guerbet alcohols, triglycerides based on C6 ,0 fatty acids, vegetable oils, branched primary alcohols, substituted cyclohexanes, Guerbet carbonates, dialkyl ethers and/or aliphatic or naphthenic hydrocarbons.
Nonionic, ampholytic and/or zwitterionic surface-active compounds distinguished by a lipophilic, preferably linear, alkyl or alkenyl group and at least one hydrophilic group may be used as emulsifiers or co-emulsifiers.
The hydrophilic group may be both an ionic group and a nonionic group.
Nonionic emulsifiers contain, for example, a polyol group, a polyalkylene glycol ether group or a combination of a polyol and a polyglycol ether group as the hydrophilic group.

Preferred formulations are those containing nonionic surfactants from at least one of the following groups as o/w emulsifiers: (a1) adducts of 2 to 30 moles of ethylene oxide and/or 0 to 5 moles of propylene oxide with linear fatty alcohols containing 8 to 22 carbon atoms, with fatty acids containing 12 to 22 carbon atoms and with alkylphenols containing 8 to 15 carbon atoms in the alkyl group; (a2) C,2"8 fatty acid monoesters and diesters of adducts of 1 to 30 moles of ethylene oxide with glycerol; (a3) glycerol monoesters and diesters and sorbitan monoesters and diesters of saturated and unsaturated fatty acids containing 6 to 22 carbon atoms and ethylene oxide adducts thereof; (a4) alkyl mono- and -oligoglycosides containing 8 to 22 carbon atoms in the alkyl radical and ethoxylated analogs thereof and (a5) adducts of 15 to 60 moles of ethylene oxide with castor oil and/or hydrogenated castor oil; (a6) polyol and in particular polyglycerol esters such as, for example, polyglycerol polyricinoleateor polyglycerolpoly-12-hydroxystearate. Mixtures of compounds from several of these classes are also suitable. The addition products of ethylene oxide and/or propylene oxide with fatty alcohols, fatty acids, alkylphenols, glycerol monoesters and diesters and sorbitan mono-esters and diesters of fatty acids or with castor oil are known commercially available products. They are homolog mixtures of which the average degree of alkoxylation corresponds to the ratio between the quantities of ethylene oxide and/or propylene oxide and substrate with which the addition reaction is carried out. C,2"8 fatty acid monoesters and diesters of adducts of ethylene oxide with glycerol are known as refatting agents for cosmetic formulations from DE-PS 20 24 051. C8"8 alkyl mono- and oligoglycosides, their production and their use as surfactants are known, for example, from US 3,839,318, US
3,707,535, US 3,547,828, DE-OS 19 43 689, DE-OS 20 36 472 and DE-A1 30 01 064 and also from EP-A 0 077 167. They are produced in particularby reacting glucose or oligosaccharides with primary C8"8 alcohols. So far as the glycoside unit is concerned, both monoglycosides in which a cyclic sugar unit is attached to the fatty alcohol by a ylycoside bond and oligomeric glycosides with a degree of oligomerization of preferably up to about 8 are suitable. The degree of oligomerization is a statistical mean value on which the homolog distribution typical of such technical products is based. In addition, zwitterionic surfactants may be used as emulsifiers. Zwitterionic surfactants are surface-active compounds which contain at least one quaternary ammonium group and at least one carboxylate and one sulfonate group in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as the N-alkyl-N,N-dimethyl ammonium glycinates, for example cocoalkyl dimethyl ammonium glycinate, N-acylaminopropyl-N,N-dimethyl ammonium glycinates, for example cocoacylaminopropyl dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazo-lines containing 8 to 18 carbon atoms in the alkyl or acyl group and cocoacyl-aminoethyl hydroxyethyl carboxymethyl glycinate. The fatty acid amide derivative known under the CTFA name of Cocoamidopropyl Betaine is particularly preferred. Ampholytic surfactants are also suitable emulsifiers.
Ampholytic surfactants are surface-active compounds which, in addition to a C8"8 alkyl or acyl group, contain at least one free amino group and at least one -COOH- or -SO3H- group in the molecule and which are capable of forming inner salts. Examples of suitable ampholytic surfactants are N-alkyl glycines, N-alkyl propionic acids, N-alkylaminobutyric acids, N-alkyliminodipro-pionic acids, N-hydroxyethyl-N-alkylamidopropyl glycines, N-alkyl taurines, N-alkyl sarcosines, 2-alkylaminopropionic acids and alkylaminoacetic acids containing around 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-cocoalkylaminopropionate, cocoacylaminoethyl aminopropionate and C,2"8 acyl sarcosine.
Suitable w/o emulsifiiers are: (b1) adducts of 2 to 15 moles of ethylene oxide with castor oil andlor hydrogenated castor oil; (b2) partial esters based on linear, branched, unsaturated or saturated C,2,22 fatty acids, ricinoleic acid and 12-hydroxystearic acid and glycerol, polyglycerol, penta-erythritol, dipentaerythritol, sugar alcohols (for example sorbitol) and polyglu-cosides (for example cellulose); (b3) trialkyl phosphates; (b4) wool wax alcohols; (b5) polysiloxane/polyalkyl polyether copolymers and corresponding derivatives; (b6) mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohol according to DE-PS 11 65 574 and (b7) polyalkylene glycols.
Superfatting agents may be selected from such substances as, for example, polyethoxylated lanolin derivatives, lecithin derivatives, polyol fattyacid esters, monoglycerides and lFatty acid alkanolamides, the fatty acid alkanolamides also serving as foam stabilizers. Suitable thickeners are, for example, polysaccharides, more especially xanthan gum, guar-guar, agar-agar, alginates and tyloses, carboxymethyl cellulose and hydroxyethyl cellulose, also relatively high molecular weight polyethylene glycol mono-esters and diesters of fatty acids, polyacrylates, polyvinyl alcohol and polyvinyl pyrrolidone, surfactants such as, for example, narrow-range fatty alcohol ethoxylates or alkyl oligoglucosides and electrolytes, such as sodium chloride and ammonium chloride.
Suitable cationic polymers are, for example, cationic cellulose derivatives, cationic starch, copolymers of diallyl ammonium salts and acrylamides, quaternized vinyl pyrrolidone/vinyl imidazole polymers such as, for example, Luviquat(É~ (BASF AG, Ludwigshafen, FRG), condensation products of polyglycols and amines quaternized collagen polypeptides such as, for example, Lauryldimonium Hydroxypropyl Hydrolyzed Collagen (Lame-quat(~)L, Grunau GmbH), polyethyleneimine, cationic silicone polymers such as, for example, Amidomethicone or Dow Corning, Dow Corning Co., USA, copolymers of adipic acid and dimethylaminohydroxypropyl diethylenetriamine (Cartaretine(~), Sandoz AG, CH), polyaminopolyamides as described, for example, in FR-A 2 252 840 and crosslinked water-soluble polymers thereof, cationic chitin derivatives such as, for example, quaternized chitosan, option-ally in microcrystalline distribution, cationic guar gum such as, for example, Jaguar~g)CBS, Jaguar(E~)C-17, Jaguartl~)C-16 of Celanese, USA, quaternized ammonium salt polymers such as, for example, Mirapol~ A-15, Mirapol g) AD-1, Mirapol~)AZ-1 of Miranol, USA.
Suitable silicone compounds are, for example, dimethyl polysilox-anes, methylphenyl polysiloxanes, cyclic silicones and amino-, fatty-acid-, alcohol-, polyether-, epoxy-, fluorine- and/or alkyl-modified silicone com-pounds. In the context of the invention, biogenic agents are, for example, plant extracts and vitamin complexes. Conventional film formers are, for example, chitosan, microcrystalline chitosan, quaternized chitosan, polyvinyl pyrrolidone, vinyl pyrrolidone/vinyl acetate copolymers, polymers of the acrylicacid series, quaternary cellulose derivatives, collagen, hyaluronic acid or salts thereof and similar compounds. Suitable preservatives are, for example, phenoxyethanol, formaldehyde solution, parabens, pentanediol or sorbic acid.
Suitable pea.lescers are, for example, glycol distearic acid esters, such as ethylene glycol distearate, and also fatty acid monoglycol esters. The dyes used may be selected from any of the substances which are licensed and suitable for cosmetic purposes, as listed for example in the publication "Kos-metische Farbemittel" of the Farl,storrkommission der Deutschen For-schungsgemeinschaft, published by Verlag Chemie, Weinheim, 1984, pages 81-106. These dyes are normally used in concentrations of 0.001 to 0.1 % by weight, based on the mixh~re as a whole.
In all, the auxiliaries and additives may make up 1 to 50 and preferably 5 to 40% by weight of the formulations.
The following Examples are intended to illustrate the invention without limiting it in any way.

Examples A quantitative suspension test was carried out with the corresponding test germs to determine germicidal activity. A cationic biopolymer (Hydagen~
CMF, Henkel KGaA, Dusseldorf/FRG) in the form of a 1 % by weight solution in demineralized water containing an addition of 0.7% by weight of benzoic acid (Examples 1 and 2) or 0.4% by weight of glycolic acid (Examples 3 and CA 02232422 l998-03-l6 4) was used for this test. The test germs used were the yeasts Candida albicans ATCC 10231 and Malassezia fuffur (= Pityrosporum ovale). 0.1 ml of the yeast suspensions was added to and thoroughly mixed with 10 g of the test samples. After an incubation period of 4 h to 7 d, the germ content in the mixtures was determined. The results are set out in Table 1 below.

Table 1 Germ destruction with cationic biopolymers Example Test germ; Germ ccnte.,t after contact time germ counVml 4h 1d 3d 7d Candida albicans < 10 < 10 < 10 < 10 4.8* 108 2 Malassezia furfur ~ 10 < 10 < 10 < 10 1 8*107 3 Candida albicans < 10 < 10 < 10 < 10 4.8 * 1 o8 4 Malassezia furfur 2*104 < 10 < 10 < 10 1.8* 107

Claims (2)

1. The use of chitosan for the production of antidandruff formulations.

2. The use of chitosan for the production of antithrush formulations.