CN1241934A - Hair treatment composition containing metal-amino acid complex - Google Patents

Abstract

The present invention relates to rinse-off hair treatment compositions for improved delivery of amino acids to the hair and/or scalp comprising a particulate metal-amino acid complex, (b) at least one surfactant, and (c) a deposition aid.

Description

Hair treatment composition containing metal-amino acid complex

technical field

The present invention relates to hair treatment compositions, especially hair treatment compositions which can be rinsed off from the scalp after use and which contain amino acid actives which condition or nourish the hair or roots.

current technology

Amino acids are known to play an important role in the nourishment of human hair roots and the growth of human hair. For example, keratin hydrolysates are a conventional component of shampoos and the like and are a source of amino acids in free and peptide form. Numerous patent applications have described the use of a series of amino acids in topical lotions or tonics for the treatment of alopecia and other skin, scalp and hair disorders.

However, the effective action of rinse-off hair treatment formulations must be delivered to the site of action, and the beneficial effects of the substances used (such as amino acids) are often limited due to the fact that most of them will be in the rinse-off phase was removed.

A common solution to this problem is to prolong the coating time and increase the active ingredient concentration in the formulation. For example, Franz et al. in Fundam. Appl. Toxicol. 21 (1993) 213-221 have demonstrated that human product formulations of different species prototypes have different penetration profiles as a function of applied dose. But this is not suitable for daily use conditions, and prolonged contact time will cause damage to the barrier.

Therefore, there is a need for improved amino acid delivery in rinse-off hair treatments.

Metal-amino acid complexes are known and available in the prior art. A large body of literature suggests that such complexes can be administered to animals as food supplements in a non-toxic manner as a means of supplying metals. Amino acids can reduce the toxicological properties of heavy metals. In the field of human health care, metal-amino acid complexes have been applied to hair coloring compositions (copper or zinc salts of cysteine, US 4 173 453), antipruritics (zinc-amino acid conjugates, WO92/ 10178) and anti-inflammatory cream (SU 1382477). But none of them describe the improvement of deposition/fastness of amino acid moieties in topical formulations. GB 937 362 proposes a composition for skin, hair and nail care or growth, containing one or more α-amino acid magnesium compounds in the composition, the literature believes that such amino acid residues are specifically magnesium Carriers introduced into skin and hair cells. US 4,652,455 discloses a non-rinse hair conditioning product which contains a "zinc releasing component" which replenishes the hair fiber with zinc. The zinc-releasing compound may be an amino acid complex of zinc, but is preferably zinc-protein or zinc keratin.

It has been found that the deposition of amino acids in rinse-off hair treatment compositions can be enhanced by incorporating in the composition amino acids which form complexes with metal ions. Such an approach offers performance and cost advantages because it improves the delivery of the amino acid nutrient per unit dose to the targeted substrate (ie, hair and/or scalp).

Summary of the invention

In one aspect, the present invention provides a rinse-off hair treatment composition for improving the delivery of amino acids to the hair and/or scalp, the composition comprising:

(a) a particulate metal-amino acid complex;

(b) at least one surfactant; and

(c) Deposition aids.

In another aspect, the present invention provides a method of enhancing the deposition of an amino acid in a rinse-off hair treatment composition, the method comprising: incorporating said amino acid into the composition in the form of a particulate metal-amino acid complex.

In a third aspect, the present invention provides the use of a particulate metal-amino acid complex for enhancing the deposition of amino acids in rinse-off hair treatment compositions.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

amino acid

Examples of amino acid moieties in the particulate metal-amino acid complex are derived from, including:

arginine

Aspartic acid

Citrulline

cysteine

cystine

cystathionine

glutamic acid

Glutamine

Glycine

Isoleucine

Lysine

Methionine

Ornithine

serine, and

Valine

Particular preference is given to cysteine, arginine, serine, glutamic acid, glutamine, isoleucine, lysine, methionine and valine.

Derivatives of said amino acids may also be employed in the present invention. For example, derivatives in which the free amino group ( _-NH2 ) of the amino acid is modified with one or more of the following groups are included:

(i) Acyl groups, such as N-alkanoyl (alkanoyl), wherein the alkanoyl moiety has an alkyl chain of 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, such as N-butyryl, N-hexanoyl and N-octanoyl;

(ii) ester groups such as those wherein the alkyl group is a straight chain alkyl group containing 1 to 20 carbon atoms, preferably 1 to 4 carbon atoms, such as methyl, ethyl and n-propyl;

(iii) amino acid residues; and

(iv) Peptide residues containing 2 to 8 amino acid residues.

Mixtures of amino acids or derivatives thereof may also be employed in the present invention. The unimolecular metal complex itself may also contain non-identical amino acids.

Metal ion

Preferred metal ions are at least divalent.

Examples of metal ions in the resulting particulate metal-amino acid complex include: Fe, Cu, Ca, Mn, Sn, Ti and Zn. The most preferred metal ion is Zn; this is considered from the protective effect on hair damage.

Mixtures of metal ions may also be employed in the present invention. Also, the metal complex in the same molecule may contain more than one metal ion, and these metal ions may be the same or different.

In more preferred compositions of the invention, the particulate metal-amino acid complex is zinc cysteine or zinc glutamate or a mixture of both.

granularity

The average particle size of the metal-amino acid complex in the composition of the invention is in the range of 0.05 to 50 microns. Our experiments (using confocal laser scanning microscopy to examine the development of particle deposition on the skin using fluorescent microspheres of different sizes as model particles) showed that particle size has an impact on the extent and location of deposition, but not on targeted delivery to the hair follicle. A more preferred average particle size is from 3 to 10 microns.

The amount of particulate metal-amino acid complex incorporated in the compositions of the present invention is suitably from about 0.001% to about 10%, more preferably from about 0.1% to about 5% by weight of the total composition.

Surfactant

The compositions of the present invention contain at least one surfactant, preferably selected from the group consisting of anionic, cationic, nonionic, amphoteric and zwitterionic surfactants, and mixtures thereof.

Particularly preferred hair treatment compositions according to the invention are shampoo compositions wherein at least one surfactant provides a detersive benefit. Detersive surfactants are preferably selected from anionic, nonionic, amphoteric and zwitterionic surfactants, and mixtures thereof.

Suitable anionic surfactants include alkyl sulfates, alkyl ether sulfates, alkaryl sulfonates, alkanoyl isethionates, alkyl succinates, alkyl sulfosuccinates, N -alkoyl sarcosinates, alkyl phosphates, alkyl ether phosphates, alkyl ether carboxylates and alpha-olefin sulfonates, especially their sodium, magnesium, ammonium, mono -, di- and triethanolamine salts. The alkyl and acyl groups typically contain 8 to 18 carbon atoms and may be unsaturated. The alkyl ether sulfates, alkyl ether phosphates and alkyl ether carboxylates may contain 1 to 10 ethylene oxide or propylene oxide units per 1 molecule, and preferably 2 to 3 units per 1 molecule. ethylene oxide units.

Examples of suitable anionic surfactants include sodium oleoyl succinate, ammonium lauryl sulfosuccinate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, triethanolamine dodecylbenzenesulfonate, coconut oil Sodium Isethionate, Sodium Lauryl Isethionate, and Sodium N-Lauroyl Sarcosinate. The most preferred anionic surfactants are sodium lauryl sulfate, triethanolamine lauryl sulfate, triethanolamine monolauryl phosphate, sodium lauryl ether phosphate 1EO, 2EO and 3EO, ammonium lauryl phosphate and lauryl 1EO, 2EO and 3EO Ammonium ether sulfate.

Nonionic surfactants suitable for use in the compositions of the present invention include linear or branched aliphatic (C8-C18) primary or secondary alcohols or phenols with alkylene oxides, typically condensation products of ethylene oxide, and typically have a 6 to 30 oxirane groups. Other suitable nonionic surfactants include mono- or di-alkanolamides. Examples thereof include coco mono- or di-ethanolamide and coco mono-isopropanolamide.

Amphoteric and zwitterionic surfactants suitable for use in the compositions of the present invention include: alkyl amine oxides, alkyl betaines, alkylamidopropyl betaines, alkyl sultaines (sulfobetaines), alkyl Alkyl glycinates (esters), alkyl carboxyglycinates (esters), alkyl amphopropionates, alkyl amphoglycinates, alkylamidopropyl hydroxy sultaines, acyl taurates (esters) and Acyl glutamate (ester), wherein the alkyl and acyl groups have 8 to 19 carbon atoms. Examples thereof include: laurylamine oxide, cocodimethylsulfopropyl betaine and preferably lauryl betaine, cocamidopropyl betaine and sodium cocoamphopropionate.

The content of said surfactant in the shampoo composition of the present invention is 0.1% to 50% by weight, preferably 0.5% to 30% by weight.

The hair treatment compositions of the present invention may also take the form of hair conditioning compositions which preferably contain one or more cationic surfactants. Cationic surfactants are especially preferred because of the conditioning benefits these ingredients provide to the hair.

Examples of cationic surfactants include:

Quaternary ammonium hydroxides, such as tetramethylammonium hydroxide, alkyltrimethylammonium hydroxide, wherein the alkyl group has about 8 to 22 carbon atoms; specific examples are octyltrimethylammonium hydroxide, dodecane Trimethyl ammonium hydroxide, cetyl trimethyl ammonium hydroxide, octyl dimethyl benzyl ammonium hydroxide, decyl dimethyl benzyl ammonium hydroxide, stearyl dimethyl benzyl ammonium hydroxide Ammonium Oxide, Didodecyldimethylammonium Hydroxide, Dioctadecyldimethylammonium Hydroxide, Tallowtrimethylammonium Hydroxide, Cocotrimethylammonium Hydroxide and their corresponding salts, For example chloride.

Hexadecyl pyridinium hydroxide and its salts, e.g. chlorides

Quaternium-5

Quaternium-31

Quaternium-18

and their mixtures.

In the hair conditioning compositions of the present invention, cationic surfactants are preferably present at levels of from 0.01% to 10%, more preferably from 0.05% to 5%, most preferably from 0.1% to 2%, by weight of the composition.

deposition aid

According to the invention, the hair treatment compositions contain polymeric water-soluble deposition aids suitable for metal-amino acid complex particles. The so-called "deposition aid" refers to an agent that can enhance the deposition of metal-amino acid complex particles on the target site (ie hair and/or scalp).

The deposition aid should generally be present at a level of from 0.01% to 5%, preferably from about 0.05% to 1%, more preferably from about 0.08% to about 0.5% by weight. The deposition aid can be a homopolymer, or consist of two or more types of monomers. The molecular weight of the polymers is usually in the range of 5000 and 10 000 000, generally at least 10 000, and preferably in the range of 100 000 to about 2 000 000. Such polymers should have cationic nitrogen-containing groups, such as quaternary ammonium or protonated amino groups, or mixtures thereof.

It has been found that the deposition aid must have a cationic charge density defined as the reciprocal of the molecular weight of polymer monomer units having a charge of at least 0.1 meq/g, preferably about 0.8 meq/g or higher. The cationic charge density should not exceed 4 meq/g, preferably below 3 meq/g, more preferably below 2 meq/g. The charge density can be measured by conductivity analysis, and the charge density should be within the above-mentioned range under the pH condition required for use, which is generally about 3 to 9, preferably between 4 and 8.

Cationic nitrogen-containing groups are generally present as substituents on a portion of all monomeric units of the deposition aid. Thus, when the polymer is not a homopolymer, it may contain nonionic spacer monomer units. Such polymers are described in the CTFA Cosmetic Ingredient Inventory, 3rd Edition. The ratio of cations to nonionic monomeric units is chosen such that the polymer has a cationic charge density within the range specified above.

Suitable cationic deposition aids include, for example, copolymers of vinyl monomers containing cationic amine or quaternary ammonium functionality with water-soluble spacer monomers such as (meth)acrylamide, alkyl and dialkyl(meth)acrylamides, alkyl(meth)acrylates, vinylcaprolactone and vinylpyrrolidine. The alkyl and dialkyl substituted monomers preferably have C1-C7 alkyl groups, more preferably C1-3 alkyl groups. Other suitable spacers include vinyl esters, vinyl alcohol, maleic anhydride, propylene glycol and ethylene glycol.

The cationic amines can be primary, secondary or tertiary, depending on the particular type and pH of the composition. Secondary and tertiary amines are generally preferred, and tertiary amines are especially preferred.

Amine substituted vinyl monomers as well as amines can be polymerized in the amine form and subsequently converted to ammonium by quaternization.

Suitable cationic amino and quaternary ammonium monomers include, for example, vinyl compounds which can be replaced by dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, monoalkylaminoalkyl acrylates, Monoalkylaminoalkyl methacrylates, trialkylmethacryloxyalkylammonium salts, trialkylacrylateoxyalkylammonium salts, diallyl quaternary ammonium salts; and cyclic cation-containing Vinyl quaternary ammonium monomers containing nitrogen rings (eg, pyridinium, imidazolium, and quaternized pyrrolidine), such as alkylvinylimidazolium, alkylvinylpyridinium, and alkylvinylpyrrolidinium salts. The alkyl moieties of these monomers are preferably lower alkyls (eg C1-C3 alkyls), more preferably C1 and C2 alkyls.

Amine substituted vinyl monomers suitable for use in the present invention include: dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, dialkylaminoalkylacrylamides and dialkylaminoalkylmethyl Acrylamide, wherein said alkyl group is preferably C1-C7 hydrocarbon group, more preferably C1-C3 alkyl group.

The deposition aid may contain a mixture of monomer units derived from amine- and/or quaternary ammonium-substituted monomers and/or compatible spacer monomers.

Suitable deposition aids include, for example: cationic copolymers of 1-vinyl-2-pyrrolidine and 1-vinyl-3-methyl-imidazolium salts (e.g. chloride salts) (in cosmetics, toiletries and Fragrance Association "CTFA" industry known as quaternized hydroxyethyl fiber-16 (Polyquaternium-16)); 1-vinyl-2-pyrrolidine and dimethylaminoethyl methacrylate copolymer (in CFTA Known in the industry as quaternized hydroxyethyl fiber-11 (Polyquaternium-11)); cationic diallyl quaternary ammonium-containing polymers include, for example, dimethyl diallyl ammonium chloride homopolymer (industrial (CFTA) known as Polyquaternium 6); inorganic acid salts of amino-alkyl esters of homopolymers and copolymers of unsaturated carboxylic acids containing 3 to 5 carbon atoms, e.g. those disclosed in US Patent 4,009,256; and cationic polyacrylamides such as those disclosed in British Patent Application No. 9403156.4.

Other suitable cationic deposition aids include cationic guar derivatives such as guar hydroxypropyltrimonium chloride (sold by Celanese Corp. under its Jaguar trademark line).

Such as: JAGUAR C13S, which has low substitution of cationic groups and high viscosity. JAGUAR C15, with medium degree of substitution and low viscosity; JAGAR C17, with high degree of substitution and high viscosity; JAGUAR C16, a hydroxypropylated cationic guar derivative with low levels of substituent groups and cations quaternary ammonium groups; and, the extremely transparent JAUGAR 162, a guar gum with a low degree of substitution and medium viscosity.

Desirable deposition aids are selected from the group comprising cationic polyacrylamides, and cationic guar gum derivatives. A particularly preferred deposition aid is Jaguar C13S with a cationic charge density of 0.8 meq/g. Other particularly suitable materials include: Jaguar C15, Jaguar C17, Jaguar C16 and Jaguar C162.

Suspending agent

The compositions of the present invention may additionally optionally contain from 0.1% to 5% of suspending agents. Examples are polyacrylic acid, cross-linked polymers of acrylic acid, copolymers of acrylic acid and hydrophobic monomers, copolymers of carboxylic acid-containing monomers and acrylates, cross-linked copolymers of acrylic acid and acrylates, heteropolysaccharide gums, and crystalline forms Long-chain acyl derivatives. The long chain acyl derivatives should be selected from ethylene glycol stearate, alkanolamides of fatty acids containing 16 to 22 carbon atoms and mixtures thereof. Polyacrylic acid is commercially available as Carbopol 420, Carbopol 488 or Carbopol 493. The present invention also can adopt the cross-linked polymer of acrylic acid and polyfunctional reagent, and its commercially available product has Carbopol 910, Carbopol 934, Carbopol 940, Carbopol 941 and Carbopol 980. A suitable example of a copolymer of carboxylic acid-containing monomers and acrylates is Carbopol 1342. All Carbopol materials are sold by Goodrich Corporation under the Carbopol trademark. Another suitable suspending agent is dihydrogenated tallow phthalamide (sold by Stepan Chemical Co. under the trademark Stepan TAB-2).

Suitable crosslinked polymers of acrylic acid and acrylate esters are Pemulen TR1 or Pemulen TR2. A suitable heteropolysaccharide gum is xanthan gum, such as that sold by Kelzanmu.

conditioner

The hair treatment compositions of the present invention may also optionally contain one or more conditioning agents, such as those known to those skilled in the art. The conditioning agents may include silicones, protein hydrolysates, quaternized protein hydrolysates, and other materials known in the art to have hair conditioning properties. Silicones are the most preferred conditioning agents.

Suitable silicones include: volatile and nonvolatile silicones such as polyalkylsiloxanes, polyalkylarylsiloxanes, silicone gums and resins, cyclomethicones, Amino functional polysiloxanes, quaternary ammonium polysiloxanes and mixtures thereof. Silicone oils are particularly preferred hair conditioning agents. The polysiloxanes may be in the form of low viscosity oils which may contain high viscosity oils or gums in solution. In addition, high viscosity materials can also take the form of emulsions in water. The emulsions are high viscosity oils or solutions of gums in low viscosity oils. The particle size of the oil phase is anywhere in the range of 30 nanometers up to an average particle size of 20 microns.

The silicone oil is suitably polydimethylsiloxane with an average particle size below 20 microns and preferably below 2 microns. The smaller particle size ensures a more uniform distribution of the silicone conditioning agent in the composition when the silicone concentration is the same. Polysiloxanes having a viscosity in the range of 1,000,000 to 20,000,000 cst are preferably employed. The polysiloxanes are suitably emulsion polymerized polysiloxanes, since this ensures that very high viscosity polysiloxanes are easier to process. Polysiloxanes can also be crosslinked.

Suitable protein hydrolysates include animal protein hydrolyzed with lauryldimethyl quaternary ammonium (dimomium) hydroxypropylamino (sold under the trade name LAMEQUAT L), and hydrolyzed keratin containing sulfur-bearing amino acids (sold under the trade name CROQUAT WKP name sale).

fatty alcohol

Another ingredient which may optionally be incorporated in the hair treatment compositions of the present invention are fatty alcoholic materials. The use of these materials in the conditioning compositions of the present invention, especially those containing one or more cationic surfactant materials, is particularly beneficial. The combination of fatty alcohol and cationic surfactant in conditioning compositions is believed to be advantageous in that it results in the formation of a lamellar phase in which the cationic surfactant can be dispersed.

Preferred fatty alcohols contain 8 to 22 carbon atoms, more preferably 16 to 20 carbon atoms. Examples of preferred fatty alcohols are: cetyl alcohol and stearyl alcohol. The use of such materials also contributes to the overall conditioning performance of the compositions of the present invention.

The level of fatty alcohol material is generally from 0.01% to 10%, preferably from 0.1% to 5%, by weight of the composition. The weight ratio of cationic surfactant to fatty alcohol is preferably 10:1 to 1:10, more preferably 4:1 to 1:8, most preferably 1:1 to 1:4.

water

The hair treatment compositions according to the invention are preferably water-based. The composition suitably contains from about 20% to about 99% water by weight of the total composition.

Instructions

The compositions of the present invention are preferably rinse-off compositions, ie suitable for application to the hair and/or scalp, leaving on for a suitable period of time and then rinsing off with water. Shampoos are therefore a particularly preferred product form for the compositions of the present invention.

other optional components

Depending on the type of composition employed, the compositions according to the invention may contain one or more additional ingredients customary in hair treatment formulations. Such additional components include: opacifiers, such as polyethylene glycol distearate and ethylene glycol stearate; polymer lattices; other antimicrobial agents; foaming agents; fragrances; colorants ; Preservatives; Viscosity regulators; Proteins; Polymers; Buffer or pH regulators; Wetting agents; Herbal or other plant extracts and other natural ingredients.

The invention will be further illustrated by the following non-limiting examples, in which:

Figure 1: is the percentage deposition dose of cysteine in shampoo matrix in free form and metal complexed form on porcine skin in vitro.

Example

Material

Radiolabeled and non-radiolabeled zinc cysteine for the synthesis of cysteine was prepared as follows: L-[ ³⁵ S]-semi Both cystine (>1000 Ci/mmol) (20 mM) and dithiothreitol (5 mM) were purchased from Amersham International Plc (Little Chalfont, UK). L-cysteine (about 98%) was purchased from Sigma Chemical Co. (St Louis, MO, USA).

Dulbecco's phosphate buffered saline (10X concentration) and penicillin/streptomycin (5000 IU/ml/5000 μg/ml) were purchased from Life Engineering Ltd. (Paisley, U.K.). Anhydrous D-(+)-glucose was purchased from Sherman Chemical Co., Ltd. (Sandy, U.K.). Buffers were prepared with distilled water.

method

1. Synthesis of Zinc Cysteine

Basic zinc carbonate (10 g) was added to an aqueous solution of cysteine (14.92 g/100 ml) and heated to reflux for 16 hours while stirring. An off-white crystalline solid was collected by filtration, washed with water and air dried. The empirical formula of the complex obtained by thermogravimetric analysis is: Zn[SCH ₂ CH(NH ₂ )CO ₂ ]. The empirical formula can be confirmed by comparing the Fourier transform infrared spectrum of the product with the reference spectrum of the complex (Shindo & Brown, J. Am. Chem. Soc. 87 (1965) 1904-1909).

2. Size reduction of zinc cysteine

2.1

A suspension of zinc cysteine in distilled water (1% w/v) was sonicated with an ultrasonic probe (Soniprep, MSE, U.K.) at maximum amplitude for 5 minutes in ice.

2.2 Laser Light Scattering

Aliquots of the sonicated suspension were placed in a Malvern Mastersizer. A 300 mm lens with a 3 mm path length cell was connected to a small sample display unit which was continuously stirred. Light scattering data were analyzed using sample presentation code 0700.

Cumulative mass distributions were prepared using a computer spreadsheet software program (Microsoft Excell(R)). Obtain granular data directly from the Mastersizer output.

3. Skin Deposition Experiment

3.1 Preparation of formulations

In order to calculate the free cysteine equivalent to the specified amount of complexing material, Zn[SCH ₂ CH(NH ₂ )CO ₂ ] can be used as the empirical formula of the zinc cysteine complex, that is, half Cystine accounts for 64.96% of the total weight of the formula.

The difference between free cysteine and complexed cysteine in this assay is the difference between a preparation containing free cysteine including radiolabeled cysteine and a preparation containing complexed cysteine without any Differences in radiolabeled preparations.

Free and complexed cysteine are made into two types of shampoos. One shampoo contained the deposition aid - JAGUAR and the other did not. The shampoo has the following formulation: Composition %w/w Preparations of free cysteine Formulations of complexed cysteine Contains deposition aids Does not contain deposition aids Contains deposition aids Does not contain deposition aids cysteine 1.38 1.38 cysteine equivalent 1.38 1.38 Deposition Aid: JAGUARC13S (Guar Gum Hydroxypropyl Trimethyl Quaternary Ammonium Chloride) 0.10 - 0.10 - Sodium dodecyl sulfate 14.00 14.00 14.00 14.00 Cocamidopropyl Betaine 2.00 2.00 2.00 2.00 Dimethiconol and TEA-Dodecylbenzene Sulfonate 1.60 1.60 1.60 1.60 sodium benzoate 0.50 0.50 0.50 0.50 Amplitude 484 0.50 0.50 0.50 0.50 Glycol Distearate (and) Lauryl-4 (and) Cocamidopropyl Betaine 8.00 8.00 8.00 8.00 Sodium chloride 1.00 1.00 1.00 1.00 citric acid to pH 4.5-5.0 to pH 4.5-5.0 to pH 4.5-5.0 to pH 4.5-5.0 water to 100 to 100 to 100 to 100

To simulate the conditions of use as closely as possible, the shampoo should be diluted 10 times with water before applying to the skin. This 10-fold dilution is modeled after the dilution people would make when applying shampoo to wet hair.

For each free cysteine formulation, 45.4 μl L-[ ³⁵ S]-cysteine (480 μCi on the day of preparation), 30 μl shampoo and 224.61 μl of 0.185% w/v L-cysteine Mix in plastic microcentrifuge tubes. 300 μl of a 10-fold diluted shampoo is thus prepared, which is suitable for dosing in 10 diffusion cells; each dose contains 40 μCi of L-[ ³⁵ S]-cysteine in a volume of 25 μl and the concentration of cysteine was 1.38% w/w.

For each cysteine-complexed formulation, 1 ml of shampoo was mixed with 2.12 ml of a 0.212% w/v sonicated suspension of zinc cysteine with 6.88 ml of water. 10 ml of a 10-fold diluted shampoo is thus prepared having a cysteine concentration equal to 1.38% w/w. Prepare the zinc cysteine suspension using the ultrasonic probe method detailed in 2.1. The particle size of the reduced cysteine was detected (2.2 above) by laser light scattering. The median diameter of zinc cysteine that was mostly reduced was detected to be 8.27 μm. The particle size distribution was unimodal; 10% of the particles were smaller than 2.91 μm in diameter, and 90% of the particles were smaller than 22.46 μm.

3.2 Skin preparation

The experiments were carried out on the back skin of two-month-old pigs. The skin was first washed with 75% ethanol. This is done to remove sebum. Hair was subsequently depilated using electric scissors (Oster, U.S.A.). Subcutaneous fat was scraped off with a scalpel (Raymond & Lamb). The prepared skins were subsequently stored frozen until use. On the day of the experiment, the skin was thawed, processed to a thickness of approximately 500 μm (Deca Dermatome, Depuy Healthcare, Leeds, U.K.), and subsequently floated in Dubecco's modified phosphate buffered saline (pH 4, containing 0.1 % Glucose, DMPBS).

3.3 Skin deposition test

Diffusion experiments were performed using Teflon(R) flow-through diffusion cells (Crown Bioscientific Inc, Somerville, NJ, USA). The diffusion cell has a receiving volume of 130 μl and an exposed surface area ^of 0.38 cm. The diffusion cell was maintained at a temperature of 37°C in a metallic aluminum heating block (Posiblock(R) diffusion cell heater, Crown Glass Co.) heated by a circulating water bath. In this way, the surface temperature of the skin can be maintained at approximately 32°C, the normal skin surface temperature. The receiving chamber is filled with DMPBS to maintain good skin hydration.

For each of the four formulations, 25 µl of its 10-fold diluted formulation was applied to the skin. The volume of the dose used is selected on the basis that 5 g of product is typically applied to a scalp surface area of 700 cm ² , so the dose per unit area of undiluted shampoo is 7.1 mg/cm ² , and the dose per 0.38 cm ² It is about 2.7μl. This equates to approximately 25 μl of a 10-fold diluted product.

Quantification was performed using a 25 μl displacement pipette (Anachem, Luton, U.K.). The above formulation was applied for up to 1 minute and rinsed off with 10 x 0.5 ml DMPBS. The buffer was applied to the skin with a 1 ml Gilson pipette and removed with a disposable pipette. Rinse the skin surface three times, blotting and reapplying the buffer after each wash.

After washing, the skin was placed in a diffusion cell for 2 hours. Skin samples were removed from each diffusion cell, and the coated skin side was trimmed with a pair of scissors. In the radiolabeling test, skin samples were dissolved in 2 ml of 90% v/v Soluene-350® in distilled water. Samples were dissolved overnight at 50°C. Prior to scintillation counting, soluble samples were mixed with 16 ml of Hionic-Fluor(R) (Packard Instrument Co.).

In radiolabeling experiments, all samples used were counted on a Beckman LS6000IC liquid scintillation counter (Beckman Instruments, Inc., Fullerton, C.A., U.S.A.).

3.4 Atomic absorption spectrometry

Blank and treated skin samples (typically 10 to 20 mg) were weighed into a PTFE cannula with a threaded top and 0.25 ml of concentrated nitric acid was added. The sleeve was screwed tightly, placed in a stainless steel digestion vessel and heated at 140°C for 2 hours. After cooling, the digest was diluted to 10 ml with deionized water.

Tissue digests were analyzed by comparison to known standards by flame atomic absorption spectrometry under the following conditions: air/acetylene flame, wavelength = 213 nm, slit width = 0.7 nm.

result

The skin deposition data are summarized in Table 1. Values represent the mean of 8 to 10 parallel experiments. Values in parentheses represent 2x standard error.

Table 1 % deposition dose Without JAGUAR Contains JAGUAR free cysteine 0.51(0.26) 0.83(0.31) zinc cysteine 1.81(0.98) 4.85(1.81)

in conclusion

Statistical analysis shows: for the processing situation of two kinds of zinc cysteines, the zinc content in the skin sample measured by atomic absorption spectrometry is obviously higher than the skin value of blank control (p＜0.05, student's T test, etc. variance). In addition, the deposition of cysteine was significantly improved by the addition of Jaguar deposition aid (p<0.05, Student's T-test, equal variance). As expected, Jaguar had no effect on deposition of free cysteine (p<0.05, Student's T-test, equal variance).

Claims (9)

1. One kind improve that aminoacid is passed to hair and/or scalp float the type hair-treatment composition, said composition contains:

   (a) particle metal-amino acid complex;

   (b) at least a surfactant; With

   (c) deposition aid.
2. 2. the described compositions of claim 1, wherein said metal ion has divalent at least.
3. 3. claim 1 or 2 compositions, wherein said aminoacid is selected from cysteine, arginine, serine, glutamic acid, glutamine, isoleucine, lysine, methionine, valine, and their mixture.
4. 4. each described compositions of claim 1 to 3, wherein said particle metal-amino acid complex is cysteine zinc or zinc glutamate, or both mixture.
5. 5. require each described compositions according to aforesaid right, wherein the particle mean size of particle metal-amino acid complex is 3 to 10 microns.
6. 6. require each described compositions according to aforesaid right, wherein said composition is a kind of shampoo Compositions, it contains the washing performance surfactant of 0.5% to 30% (weight), and this surfactant is selected from anion, nonionic, both sexes and zwitterionic surfactant and composition thereof.
7. 7. require each described compositions according to aforesaid right, wherein said deposition aid is selected from cationic-type polyacrylamide and cationic guar gum derivant.
8. 8. the method for amino acid whose deposition in the type hair-treatment composition is floated in a raising, and this method comprises: the aminoacid of sneaking into particle metal-amino acid complex form in said composition.
9. 9. particle metal-amino acid complex floats application in the amino acid whose deposition in the type hair-treatment composition in raising.

Images