Hair care composition containing an anti-dandruff agent

Abstract

A composition comprising: (i) an anti-dandruff agent; (ii) a wax or wax-like substance in which the anti-dandruff agent is soluble or dispersible, wherein the melting point of the wax and substance is between 30°C and 105°C, and the substance is not a UV-absorbing sunscreen; and (iii) 10 3 Da~10 7 a cationic polymer having a weight average molecular weight of 100 Da; wherein the composition is in the form of particles having a particle size of 0.1 to 1000 μm, and wherein the wax-like substance is a C13-35 fatty alcohol; and wherein the wax is at least one of beeswax, libu laurel wax, lanolin, shellac wax, spermaceti wax, white bayberry wax, candelilla wax, carnauba wax, castor wax, esparto wax, Japan wax, ouricule wax, rice bran wax, soybean wax, tallow tree wax, ceresin wax, montan wax, ozokerite, and peat wax.

Description

Technical Field

[0001] The present invention relates to a hair care composition containing an anti-dandruff agent (particularly, piroctone olamine).

Background Art

[0002] The efficacy of an anti-dandruff shampoo or conditioner depends largely on the amount of the anti-dandruff agent attached to the scalp and hair. Usually, at the time of use, the contact time between the hair / scalp and the rinse-off hair care product is extremely short (e.g., 10 to 120 seconds), and then the composition is rinsed off. As a result, the anti-dandruff agent cannot adhere for a sufficient time. Therefore, it is desirable to adhere as much drug as possible in the limited contact time. However, the adhesion of any active ingredient (particularly, an anti-dandruff agent) via a rinse-off hair care composition presents a technical problem because a part of the amount of the particles of the anti-dandruff agent tends to be rinsed off without adhering. Increasing the amount of the anti-dandruff agent to offset the loss is a possible solution, but it is not technically appropriate and is not economically practical either.

[0003] Piroctone olamine (Octopirox (registered trademark)) is a widely used anti-dandruff agent. However, insufficient adhesion is still a technical problem. Another problem is instability in the shampoo.

[0004] US20040213751A1 (P&G) discloses a hair care composition containing pyrithione and a zinc-containing layered material that provides an augmentation factor greater than 1.

[0005] WO14124066A1 (P&G) discloses a hair care composition containing a cationic polymer and anionic particles for improving the adhesion of pyrithione.

[0006] WO2008101546 (Rovi) discloses cosmetics for protecting and / or treating the skin and / or hair, comprising an active ingredient and a carrier material in which the active ingredient is present or to which the active ingredient is bound or associated, where the carrier material contains a specific proportion of chitosan. The active substance is bound or associated with the carrier material in a fraction having chitosan and a specific proportion of polylactide, polyglycolide and / or polylactide glycolide or derivatives thereof, and the carrier material is in the form of particles having an average particle size of 10 to 1000 nm.

[0007] WO10105922A1 [Unilever] discloses particles comprising a wax-like solid and a polymeric adhesion promoter having no overall cationic charge, and a method for preparing such particles.

[0008] Our co-pending application EP19154998 (Unilever) discloses composite particles comprising a photo-labile anti-dandruff agent and an organic UV filter having a melting point of 30°C to 105°C, where the composite particles are characterized by comprising a cationic polymer having a weight average molecular weight of 1000 Da to 10000000 Da.

[0009] WO9823258A1 (Unilever) discloses a shampoo comprising piroctone olamine and 0.1 to 5 wt% polyethyleneimine for enhancing the adhesion of piroctone olamine.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0011] It has been confirmed that at least some of the problems of the prior art can be solved by the present invention.

Means for Solving the Problems

[0012] According to a first aspect, a composition is disclosed that includes the following: (i) An anti-dandruff agent; (ii) A wax or wax-like substance in which the anti-dandruff agent is soluble or dispersible, where the melting point of the wax and the substance is 30°C to 105°C, and the substance is not a UV-absorbing sunscreen; and, (iii) A cationic polymer having a weight average molecular weight of 10 3 Da to 10 7 Da; where the composition is in the form of particles having a particle size of 0.1 to 1000 microns, and where the wax-like substance is a C13-35 fatty alcohol; where the wax is at least one of beeswax, Chinese wax, lanolin, shellac wax, spermaceti wax, Japanese momme wax, candelilla wax, carnauba wax, castor wax, esparto wax, Japan wax, ouricury wax, rice bran wax, soybean wax, tallow tree wax, ceresin wax, montan wax, ozokerite or peat wax.

[0013] The inventors have confirmed that the particles of the present invention not only help more anti-dandruff agents adhere to the scalp, but also help stabilize the anti-dandruff agents (especially piroctone olamine) in hair care products such as shampoo compositions. Such agents may lose their efficacy over a period of time, presumably due to the presence of surfactants, polymers and other components that may decompose or destabilize the anti-dandruff agents.

[0014] According to a second aspect, a method for preparing the composition according to claim 1 is disclosed, wherein the method comprises heating and stirring an aqueous slurry comprising the wax or wax-like substance and the anti-dandruff agent, followed by adding the cationic polymer to the slurry and further heating the slurry at 30 to 100 °C for 5 to 60 minutes.

[0015] According to a third aspect, a hair care product comprising the composition of the first aspect is disclosed.

Mode for Carrying Out the Invention

[0016] To avoid any ambiguity, any feature of one aspect of the present invention can be used in any other aspect of the present invention. The expression "comprising" is intended to mean "including", but not necessarily "consisting of" or "composed of". In other words, the recited steps or options need not be exhaustive. It should be noted that the examples described below are intended to clarify the present invention and are not intended to limit the present invention to those examples themselves. Similarly, unless otherwise indicated, all percentages are weight / weight percentages. Except in the case of examples and comparative examples, or unless explicitly indicated, all numbers indicating amounts of materials or reaction conditions, physical properties and / or uses of materials in this "Detailed Description" and the "Claims" should be understood as being modified by the word "about". A numerical range expressed in the form "from x to y" is understood to include x and y. It is understood that when multiple preferred ranges for a particular feature are described in the form "from x to y", all ranges combining different endpoints are also contemplated. As used herein, the indefinite articles "a" or "an" and their corresponding definite article "the" mean at least one or one or more, unless otherwise specified. The various features of the present invention referred to in the individual sections above can be applied to other sections with the necessary modifications where appropriate. Accordingly, features specified in one section can be combined with features specified in other sections where appropriate. The section headings are provided for convenience only and are not intended to limit the disclosure in any way.

[0017] As used herein, "haircare product" is intended to encompass compositions for topical application to the hair or scalp of mammals, particularly humans. "Topical" means that the product is applied to the outer surface of the body. In the present invention, this is achieved by applying the haircare product to the hair or scalp. Such products can generally be classified as leave-on or rinse off, and include any product applied to improve the appearance, cleansing, odor control or overall aesthetics of the scalp and hair. The haircare product of the present invention is preferably a leave-on product. Alternatively, the haircare product of the present invention is a wash-off composition. The haircare product according to the present invention is preferably a shampoo, hair conditioner, hair cream, hair color, hair serum, mousse, hair gel or hair oil.

[0018] In a first aspect, the composition of the present invention comprises (i) an anti-dandruff agent; (ii) a wax or wax-like substance in which the anti-dandruff agent is soluble or dispersible, wherein the melting point of the wax and the substance is 30°C to 105°C, and the substance is not a UV-absorbing sunscreen; and, (iii) a cationic polymer having a weight average molecular weight of 10 3 Da to 10 7 Da; comprising Here, the composition is in the form of particles with a particle size of 0.1 to 1000 microns, and here, the wax-like substance is a C13-35 fatty alcohol; here, the wax is at least one of beeswax, Chinese wax, lanolin, shellac wax, spermaceti wax, Japanese wax tree wax, candelilla wax, carnauba wax, castor wax, esparto wax, Japan wax, ouricury wax, rice bran wax, soybean wax, tallow tree wax, ceresin wax, montan wax, ozokerite or peat wax.

[0019] The term "particle" means particles having a size in the range of 0.1 to 1000 μm, preferably 0.1 to 100 μm, and most preferably 1 to 50 μm. Preferably, the composition of the present invention is in powder form or in the form of an aqueous suspension. Such a composition preferably contains 1 to 90% by weight of particles, and the balance is water.

[0020] Alternatively, the composition of the present invention, i.e., the particles, are in powder form, preferably lyophilized powder. Its size can be measured, for example, by laser diffraction using a system (e.g., Mastersizer 2000 available from "Malvern Instruments Ltd"). The ratio of the amount of the anti-dandruff agent to the amount of the wax or wax-like substance in the fine particles is preferably 1:0.01 to 1:1000 parts by weight. TM 2000). The fine particles preferably contain 0.1 to 80% by weight of the anti-dandruff agent, 18 to 95% by weight of the wax or wax-like substance, and 0.5 to 10% by weight of the cationic polymer.

[0021] The composition of the present invention contains a wax or wax-like substance in which the anti-dandruff agent is soluble or dispersible, where the melting point of the wax and the substance is 30°C to 105°C. The wax-like substance is not a UV-absorbing sunscreen.

[0022] Wax or wax-like substance ​

[0023] The melting point indicates the temperature at which the solid and liquid forms of a pure substance can exist in an equilibrium state.

[0024] The wax of the present invention is at least one of beeswax, spermaceti wax, lanolin, shellac wax, whale wax, Japanese wax, candelilla wax, carnauba wax, castor wax, esparto wax, wood wax, oricury wax, rice bran wax, soybean wax, Chinese wax, ceresin wax, montan wax, ozokerite or peat wax. Such waxes are often selected from hydrocarbon waxes and ester waxes, which can be derived from natural sources or synthesized. Suitable hydrocarbon waxes include mineral wax, microcrystalline wax, Montana wax and low molecular weight polyethylene (e.g., polyethylene of 300 - 600 daltons). Suitable ester waxes can be obtained from unsaturated natural oils such as plant-derived triglyceride oils by hydrogenation and optionally dehydroxylation (when the substituent contains at least one hydroxyl group like castor oil). Suitable ester waxes include caster wax, candelilla wax, carnauba wax, beeswax and spermeceti wax. Natural waxes such as beeswax include different chemical classes. Synthetic esters often contain aliphatic monoesters containing at least 30 carbons and can actually be isolated natural substances like beeswax, be derived from them, or be the same compounds.

[0025] The wax-like substance of the present invention is a C13 - 35 fatty alcohol.

[0026] It is possible to use one type or blend of fatty alcohols. Preferred fatty alcohols include cetostearyl alcohol, cetyl alcohol, stearyl alcohol, eicosyl alcohol, and behenyl alcohol. Commercial fatty alcohols are nominally and predominantly one specified alcohol, but often contain small amounts (e.g., up to a total of 5 or 6 wt%) of homologues that differ by 2, 4, or 6 carbons.

[0027] Waxes and wax-like substances are not sunscreen agents that absorb ultraviolet light. For example, some sunscreen agents are described below: 2-hydroxy-4-methoxybenzophenone (also known as benzophenone-3, CAS: 131-57-7, MP 62-64 °C), 2,2-dihydroxy-4-methoxybenzophenone (CAS: 131-53-3, MP 73-75 °C), butyl methoxydibenzoylmethane (CAS: 70356-09-1, MP 81-84 °C), bis-ethylhexyl oxy-phenol methoxyphenyl triazine (Tinosorb S, CAS: 187393-00-6, MP 83-85 °C), menthyl anthranilate (CAS: 134-09-8, MP 62.5-63.5 °C), 4-methylbenzylidene camphor (enzacamene) (CAS: 36861-47-9, MP 66-69 °C), benzophenone-7 (5-chloro-2-hydroxybenzophenone) (CAS: 85-19-8, MP 96-98 °C), benzophenone-8 (dioxybenzone) (CAS: 131-53-3, MP 68 °C), benzophenone-10 (Mexenone, 2-hydroxy-4-methoxy-4'-methyl-benzophenone, CAS: 1641-17-4, MP 99-102 °C), benzophenone-12 (octabenzone) (CAS: 1843-05-6, MP 47-49 °C).

[0028] Antidandruff agent The composition (i.e., microparticles) of the present invention preferably contains 0.1 to 80% by weight, preferably 0.2 to 40% by weight, and more preferably 0.25 to 15% by weight of an anti-dandruff agent. The anti-dandruff agent is a compound that is active against dandruff and is typically an antibacterial agent, preferably an antifungal agent. The anti-dandruff agent typically exhibits a minimum inhibitory concentration of about 50 mg / mL or less against Malassezia.

[0029] The anti-dandruff agent is preferably piroctone olamine, climbazole, selenium sulfide, zinc pyrithione or zinc sulfate.

[0030] Cationic polymer The composition of the present invention also contains a cationic polymer. Preferably, the polymer is one of the following: polyamine, polyvinylpyrrolidone, polylysine, protamine, trimethylammonioethyl (meth)acrylate homopolymers and copolymers, acrylamide propyltrimethylammonium halide homopolymers and copolymers, dialkyldiallylammonium halide homopolymers and copolymers, chitosan or derivatized chitosan, cellulose or its derivatives including trimethylammonium-substituted epoxides, starch hydroxypropyltrimethylammonium halide, polyethyleneimine, or a polycondensate containing diquaternary ammonium or polyquaternary ammonium repeating units.

[0031] The term "cationic polymer" is used to distinguish such polymers from anionic polymers (i.e., negatively charged polymers) and nonionic polymers (i.e., polymers having no charge).

[0032] The molecular weight of the cationic polymer is preferably 30,000 to 1,000,000 daltons, more preferably 70,000 to 600,000 daltons, and even more preferably 150,000 to 400,000 daltons.

[0033] The zeta potential is the charge that occurs at the interface between the solid surface and its liquid medium. This potential, measured in millivolts, can arise from any of several mechanisms. Among these are the dissociation of ionogenic groups on the particle surface and the differential adsorption of solution ions into the surface region. The net charge on the particle surface affects the ion distribution in the nearby region, increasing the concentration of counterions close to the surface. Thus, an electric double layer is formed in the region of the particle-liquid interface. Therefore, the zeta potential is a function of the surface charge of the particle, the layer adsorbed at the interface, and the nature and composition of the surrounding suspension medium. This can be determined experimentally, and since it reflects the effective charge on the particles and is thus related to the electrostatic repulsive forces between them, the zeta potential has been found to be extremely suitable for the practical study and control of colloid stability and the aggregation process. To measure it with reasonable accuracy, various methods and apparatuses can be utilized. For example, the zeta potential of the particles is measured in DI water at a solids content of 50 ppm, pH 7, and 25 °C using a Malvern Nano ZS90 apparatus.

[0034] The zeta potential of the cationic polymer is preferably +10 to +100 mV. The polymer is particularly preferably chitosan. Chitosan preferably contains a chitosan component and anions. Chitosan is preferably a salt of chitosan and an amino acid. Preferably, the amino acid contains glutamine, glutamic acid, histidine, leucine, lysine, serine, threonine, arginine, or a mixture thereof, and more preferably contains arginine.

[0035] Preferably, chitosan contains at least 5%, more preferably at least 10%, on a molar basis, of protonated primary amino groups relative to the total amount of primary amino groups and protonated primary amino groups.

[0036] Preferably, the degree of deacetylation of chitosan is at least 65%, more preferably 70 - 95%, even more preferably 72 - 90%, and most preferably 75 - 85%.

[0037] The ratio of the anti-dandruff agent to the cationic polymer in the fine particles is preferably 1:0.01 to 1:1000 parts by weight.

[0038] The composition (i.e., particles) of the present invention preferably contains a co-solvent in which the anti-dandruff agent is soluble or dispersible, wherein the co-solvent is a ketone, and wherein the co-solvent is neither a wax nor a wax-like substance. This co-solvent is added to the wax or wax-like substance.

[0039] The co-solvent is preferably a ketone selected from 2-hexanone or 2-octanone or damascone.

[0040] More preferably, this ketone is damascone.

[0041] Method for preparing composite particles According to a second aspect, a method for preparing the composition of the first aspect is disclosed, wherein the method includes heating and stirring an aqueous slurry containing the wax or wax-like substance and the anti-dandruff agent, followed by adding the cationic polymer to the slurry and further heating the slurry at 30 to 100 °C for 5 to 60 minutes.

[0042] Hair care composition According to a third aspect, a hair care product containing the composition of the first aspect is disclosed. More preferably, the hair care product contains a composition (i.e., fine particles) in such an amount that the total amount of the anti-dandruff agent in the hair care product is 0.01 to 5.0% by weight.

[0043] More preferably, the hair care product is a shampoo, a hair conditioner, a hair cream, a hair color, a hair serum, a mousse, a hair gel or a hair oil.

[0044] In addition to the anti-dandruff agent present in the form of composite particles, the hair care composition according to the present invention may further contain an additional anti-dandruff agent which may be the same as, for example, the anti-dandruff agent contained inside the fine particles. Whenever present, the hair care composition of the present invention preferably contains 0.05 to 5% by weight of the additional anti-dandruff agent. The additional anti-dandruff agent is preferably selected from azoles, Octopirox® (piroctone olamine), selenium sulfide, salicylic acid and combinations thereof. The azoles include ketoconazole and climbazole, and preferably climbazole.

[0045] The hair care composition of the present invention may further contain a zinc salt. The additional zinc salt can suitably be selected from zinc salts of organic acids, zinc salts of inorganic acids, zinc oxide, zinc hydroxide or mixtures thereof.

[0046] Examples of preferred zinc salts include zinc oxide, zinc pyrrolidone carboxylate, zinc citrate, zinc carbonate, zinc chloride, zinc sulfate, zinc glycinate, zinc acetate, zinc lactate and mixtures thereof. When present, the hair care composition of the present invention preferably contains 0.1 to 5% by weight, preferably 0.2 to 3% by weight, more preferably 0.25 to 2.5% by weight of the salt based on the total weight of the composition.

[0047] The hair care composition of the present invention contains a surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, zwitterionic surfactants and mixtures thereof. The nature, type, amount and specific combination that can be used depend on the formulation of the composition and will depend largely on whether it is a shampoo, a conditioner or a conditioning shampoo.

[0048] Preferably, the hair care product of the present invention is a shampoo. Preferably, it contains a surfactant which is sodium lauryl sulfate, sodium lauryl ether sulfate, sodium lauryl ether sulfosuccinate, ammonium lauryl sulfate, ammonium lauryl ether sulfate, sodium cocoyl isethionate and lauryl ether carboxylic acid, coco betaine, cocamidopropyl betaine, sodium coco amphoacetate or a mixture thereof.

[0049] Preferably, the hair care product of the present invention contains 1 to 50%, preferably 2 to 40%, more preferably 4 to 25% of total surfactant. The hair care product of the present invention more preferably contains cosmetic ingredients. Preferably, the cosmetic ingredients are silicone, antibacterial agents other than anti-dandruff agents, foam boosters, fragrances, encapsulates (e.g., encapsulated fragrances), dyes, colorants, pigments, preservatives, thickeners, proteins, phosphate esters, buffers, pH adjusters, pearlescers (e.g., mica, titanium dioxide, titanium dioxide-coated mica, ethylene glycol distearate (INCI glycol distearate)) and / or opacifiers, viscosity modifiers, skin softeners, sunscreens, emulsifiers, sensate actives (e.g., menthol and menthol derivatives), vitamins, mineral oils, essential oils, lipids, natural actives, glycerin, natural hair nutrients such as plant extracts, fruit extracts, sugar derivatives and amino acids, microcrystalline cellulose and mixtures thereof.

[0050] Preferably, the hair care product of the present invention contains at least one cosmetic ingredient in an amount of 0.01 to 20% by weight based on the total weight of the product, more preferably 0.05 to 10% by weight, even more preferably 0.075 to 7.5% by weight, and most preferably 0.1 to 5% by weight.

[0051] The hair care product of the present invention can further also contain a synergistic antibacterial compound that provides a synergistic antibacterial effect when used in combination with its anti-dandruff active substance (e.g., zinc pyrithione) to enhance the properties of the anti-dandruff active substance and further inhibit the growth of Malassezia furfur. Non-limiting examples of these compounds include compounds having an alcohol group (e.g., honokiol, magnolol or paeonol), piperazines and phenolic compounds found in natural plant extracts (i.e., thymol and terpeniol).

[0052] The hair care product can further contain a vitamin B3 compound. A preferred vitamin B3 compound is niacinamide.

[0053] Niacinamide is known with respect to the secretion of AMP (antibacterial protein) from keratinocytes. The AMP secreted in this way, for example, improves the immunity of the scalp. Therefore, when using niacinamide, the anti-dandruff efficacy can be enhanced not only through its antifungal activity but also by enhancing the protective shield against the bacteria of the scalp itself using niacinamide. This combination could provide a more long-lasting protection against bacteria (e.g., protection up to 24 hours at most). If present, the hair care composition of the present invention preferably contains 0.1 to 5% by weight of niacinamide in the composition, more preferably 0.5 to 5% by weight, even more preferably 0.5 to 3% by weight, and optimally 1.0 to 3.0% by weight of niacinamide.

[0054] Silicone The hair care product of the present invention preferably contains silicone.

[0055] For example, the composition of the present invention can contain emulsion droplets of a silicone conditioning agent for enhancing conditioning performance.

[0056] Suitable silicones include polydiorganosiloxanes and polydimethylsiloxanes (which have the CTFA name "dimethicone"). Further, suitable for use in the compositions of the present invention (especially shampoos and conditioners) are polydimethylsiloxanes having hydroxyl end groups (which have the CTFA name "dimethiconol").

[0057] Preferably, the viscosity of the emulsified silicone is at least 10,000 cst at 25 °C, and the viscosity of the silicone is preferably at least 60,000 cst, most preferably at least 500,000 cst, and ideally at least 1,000,000 cst. Preferably, the viscosity does not exceed 10 9 cst for ease of formulation.

[0058] Examples of suitable pre-formed emulsions include Xiameter MEM1785 and microemulsion DC2-1865 available from Dow Corning. These are emulsions / microemulsions of dimethiconol. Crosslinked silicone gums can also be obtained in pre-emulsified form, which is advantageous for ease of formulation. A further preferred class of silicones for inclusion in shampoos and conditioners are amino-functional silicones. "Amino-functional silicone" means a silicone containing at least one primary, secondary or tertiary amine group or quaternary ammonium group. Examples of suitable amino-functional silicones include polysiloxanes having the CTFA name "amodimethicone".

[0059] Specific examples of amino-functional silicones suitable for use in the present invention are aminosilicone oils DC2-8220, DC2-8166 and DC2-8566 (all manufactured by Dow Corning).

[0060] Preferably, the total amount of silicone is 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, and most preferably 0.5 to 3% by weight.

[0061] pH of the composition Preferably, the pH of the hair care product of the present invention is preferably 3 to 7, more preferably 4 to 7, even more preferably 4 to 6.5, and most preferably 4.2 to 6.5.

[0062] Shampoo When the hair care product of the present invention is a shampoo, it is generally aqueous, that is, they have water or an aqueous solution or a lyotropic liquid crystal phase as their main component.

[0063] Suitably, the shampoo composition contains 50 to 98% water, preferably 60 to 92% water.

[0064] Preferably, the shampoo composition contains one or more cationic polymers for conditioning the hair.

[0065] Suitable cationic polymers include homopolymers that are cationically substituted or homopolymers that can be formed from two or more types of monomers. The weight average (Mw) molecular weight of the polymer is generally 100,000 to 3 million daltons. The polymer has a cationic nitrogen-containing group (for example, a quaternary ammonium group or a protonated amino group or a mixture thereof). If the molecular weight of the polymer is too low, the conditioning effect is poor. If it is too high, the extensional viscosity becomes high, and as a result, there may be a problem that the composition becomes filamentous when poured.

[0066] Cationic nitrogen-containing groups generally exist as substituents in a portion of all monomer units of a cationic polymer. Thus, if the polymer is not a homopolymer, it can include spacer non-cationic monomer units. Such polymers are described in the "CTFA Cosmetic Ingredient Directory, 3rd edition". The ratio of cationic monomer units to non-cationic monomer units is selected so as to obtain a polymer having a cationic charge density in the required range (which is generally 0.2 - 3.0 meq / gm). The cationic charge density of the polymer is appropriately measured by the Kjeldahl method described in the United States Pharmacopeia under a chemical test for nitrogen measurement.

[0067] Suitable cationic polymers include copolymers of vinyl monomers having cationic amine functionality or quaternary ammonium functionality and water-soluble spacer monomers (e.g., (meth)acrylamide, alkyl and dialkyl (meth)acrylamide, alkyl (meth)acrylate, vinyl caprolactone, and vinyl pyrrolidine). The alkyl and dialkyl substituted monomers preferably have a C1-C7 alkyl group, more preferably a C1-3 alkyl group. Other suitable spacers include vinyl esters, vinyl alcohol, maleic anhydride, propylene glycol, and ethylene glycol.

[0068] The cationic amine can be a primary, secondary, or tertiary amine depending on the particular species and the pH of the composition. Generally, secondary and tertiary amines are preferred, and particularly tertiary amines are preferred.

[0069] Amine-substituted vinyl monomers and amines are polymerizable in amine form and can then be converted to ammonium by quaternization.

[0070] The cationic polymer can comprise a mixture of monomer units derived from monomers substituted with amines and / or quaternary ammonium and / or compatible spacer monomers.

[0071] Suitable cationic polymers (non-limiting examples) include the following: · Cationic diallyl quaternary ammonium-containing polymers, such as dimethyldiallylammonium chloride homopolymer, and copolymers of acrylamide and dimethyldiallylammonium chloride (which are, respectively, referred to in the industry (CTFA) as polyquaternium 6 and polyquaternium 7); · Mineral acid salts of amino-alkyl esters of homopolymers and copolymers of unsaturated carboxylic acids having 3 to 5 carbon atoms (described in U.S. Patent No. 4,009,256); · Cationic polyacrylamides (described in WO95 / 22311).

[0072] Another cationic polymer that can be used includes cationic polysaccharide polymers, such as cationic cellulose derivatives, cationic starch derivatives, and cationic guar gum derivatives.

[0073] A particularly suitable type of cationic polysaccharide polymer that can be used is a cationic guar gum derivative, such as guar hydroxypropyltrimethylammonium chloride (commercially available from Rhodia under the JAGUAR trademark series). Examples of such materials are JAGUAR C13S, JAGUAR C14, and JAGUAR C17.

[0074] Any mixture of the above cationic polymers can be used.

[0075] Preferably, the hair care product of the present invention contains 0.01 to 5%, preferably 0.02 to 1%, more preferably 0.05 to 0.8% of the cationic polymer.

[0076] The hair care product of the present invention can further include a cationic adhesion polymer, which is a cationic polygalactomannan having an average molecular weight (Mw) of 1 million to 2.2 million g / mol and a cationic substitution degree of 0.13 to 0.3.

[0077] Polygalactomannan is a polysaccharide mainly composed of galactose units and mannose units, and is usually found in the endosperm substances of seeds of leguminous plants such as guar, locust bean, tara, and fenugreek, and other members of the Leguminosae family. Polygalactomannan consists of a backbone composed of 1→4-linked β-D-mannopyranosyl main chain units (also referred to as mannoside units or mannoside residues), and repeating 1→6-linked α-D-galactosyl side chains (also referred to as galactoside units or galactoside residues) branching from the 6th carbon atom of the mannopyranose residues in the polymer backbone. The polygalactomannans of different species of leguminous plants differ from each other in the frequency of occurrence of galactoside side chain units branching from the polymannoside backbone. Mannoside units and galactoside units are collectively referred to as glycoside units or glycoside residues in this specification. The average ratio of mannoside units to galactoside units in the polygalactomannan contained in guar gum (hereinafter referred to as "guar") is about 2:1.

[0078] Suitable cationic polygalactomannans include guar and hydroxyalkyl guar (e.g., hydroxyethyl guar or hydroxypropyl guar) cationically modified by chemical reaction with one or more derivatizing agents.

[0079] In a typical composition, the amount of the cationic polygalactomannan generally ranges from about 0.05 to 1% by weight of the composition, preferably from 0.1 to 0.8% by weight, and more preferably from 0.2 to 0.6% by weight.

[0080] The hair care product of the present invention may further contain an anionic polymer rheology modifier such as a carboxylic acid polymer.

[0081] As used in connection with the present invention, the term "carboxylic acid polymer" generally means a homopolymer or copolymer obtained from the polymerization of ethylenically unsaturated monomers (hereinafter referred to as "carboxylic acid monomers") containing pendant carboxylic acid groups.

[0082] Suitable carboxylic acid monomers generally have one or two carboxylic acid groups, one carbon-carbon double bond, and in total contain from 3 to about 10 carbon atoms, more preferably from 3 to about 5 carbon atoms.

[0083] Specific examples of suitable carboxylic acid monomers include the following: α-β-unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; and α-β-unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, maleic acid and aconitic acid. Salts, esters or anhydrides of the α-β-unsaturated monocarboxylic acids or α-β-unsaturated dicarboxylic acids described above can also be used. Examples include the following: semi-esters of α-β-unsaturated dicarboxylic acids with C 1-4 alkanols such as monomethyl fumarate; cyclic anhydrides of α-β-unsaturated dicarboxylic acids such as maleic anhydride, itaconic anhydride and citraconic anhydride; and esters of acrylic acid or methacrylic acid with C 1-30 alkanols such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, hexadecyl acrylate and octadecyl acrylate.

[0084] Optionally, another ethylenically unsaturated monomer can be copolymerized within the carboxylic acid polymer backbone. Examples of such other ethylenically unsaturated monomers include styrene, vinyl acetate, ethylene, butadiene, acrylonitrile and mixtures thereof. The carboxylic acid polymer may preferably have a molecular weight of at least one million daltons.

[0085] Suitable examples include C 1-4 Crosslinked copolymers polymerized from one or more comonomers selected from alkyl acrylates or methacrylates (e.g., ethyl acrylate) and acrylic acid, methacrylic acid, and mixtures thereof are included. Such materials can generally be referred to by the INCI name of the acrylate copolymer. Commercially available examples include Aculyn® 33 from Rohm and Haas.

[0086] C of acrylic acid or methacrylic acid 10-30 Crosslinked copolymers polymerized from alkyl esters of acrylic acid or methacrylic acid and one or more comonomers selected from acrylic acid, methacrylic acid, and their respective C 1-4 alkyl esters are also suitable. Such materials can generally be referred to by the INCI name of acrylate / C10-30 alkyl acrylate crosspolymer. Commercially available examples include Carbopol® polymers 1342 and 1382 from Lubrizol Advanced Materials.

[0087] Copolymers that may be crosslinked from acrylic acid or methacrylic acid, alkyl acrylates, and ethoxylated hydrophobic modified alkyl acrylates are also suitable. Such materials can generally be referred to by the INCI names of acrylate / steareth-20 methacrylate copolymer, acrylate / beheneth-25 methacrylate copolymer, acrylate / steareth-20 methacrylate crosspolymer, and acrylate / palmiteth-25 acrylate copolymer. Commercially available examples include Aculyn® 22, 28, or 88 from Rohm & Haas, and Synthalen® from 3V Sigma.

[0088] The carboxylic acid is preferably a carbomer such as a homopolymer of acrylic acid crosslinked with allyl ether of pentaerythritol or allyl ether of sucrose.

[0089] Any mixture of the foregoing materials can be used.

[0090] Preferably, the hair care product of the present invention contains 0.1 to 3.0% by weight, more preferably 0.4 to 1.5% by weight, of a carboxylic acid polymer in the composition.

[0091] In a formulation containing an anionic polymer rheology modifier such as the carboxylic acid polymer described above, it is often necessary to neutralize at least a part of the free carboxyl groups by adding an inorganic base or an organic base. Examples of suitable inorganic bases or organic bases include alkali metal hydroxides (e.g., sodium hydroxide or potassium hydroxide), sodium carbonate, ammonium hydroxide, methylamine, diethylamine, trimethylamine, monoethanolamine, triethanolamine, and mixtures thereof.

[0092] The hair care product of the present invention can further contain a nonionic polymer rheology modifier selected from one or more nonionic cellulose ethers.

[0093] Suitable nonionic cellulose ethers for use as nonionic polymer rheology modifiers in the present invention include the following: (C 1-3 alkyl) cellulose ethers, such as methyl cellulose and ethyl cellulose; hydroxy(C 1-3 alkyl) cellulose ethers, such as hydroxyethyl cellulose and hydroxypropyl cellulose; mixed hydroxy(C 1-3 alkyl) cellulose ethers, such as hydroxyethyl hydroxypropyl cellulose; and, (C 1-3 alkyl) hydroxy(C 1-3Alkyl) cellulose ethers, such as hydroxyethyl methyl cellulose and hydroxypropyl methyl cellulose. Preferred nonionic cellulose ethers for use as nonionic polymer rheology modifiers in the present invention are water-soluble nonionic cellulose ethers such as methyl cellulose and hydroxypropyl methyl cellulose. The term "water-soluble" means, in the context of the present invention, a water solubility of at least 1 gram, more preferably at least 3 grams, and most preferably at least 5 grams in 100 grams of distilled water at 25 °C and 1 atmosphere. This level indicates the formation of a macroscopically isotropic or transparent colored or colorless solution.

[0094] Methyl cellulose and hydroxypropyl methyl cellulose are commercially available from Dow Chemical in many viscosity grades under the METHOCEL® trademark series.

[0095] Mixtures of any nonionic cellulose ethers may also be suitable. In typical compositions according to the present invention, the level of nonionic cellulose ethers is generally in the range of about 0.01 to about 2.0 wt%, preferably 0.1 to 0.5 wt%, more preferably 0.1 to 0.3 wt% based on the total weight of the composition.

[0096] Preferably, the hair care product of the present invention contains 0.1 to 0.3 wt% of nonionic cellulose ether.

[0097] The hair care product of the present invention can contain further optional ingredients for enhancing performance and / or consumer acceptance. Examples of such ingredients include fragrances, dyes and pigments, and preservatives. These ingredients are each present in an amount effective to achieve their purpose. Generally, these optional ingredients are included at levels of up to 5 wt% individually based on the total weight of the composition.

[0098] Form of use The hair care products of the present invention are mainly intended for topical application to the hair and scalp.

[0099] When the hair care product is shampoo, it is topically applied to the hair and then massaged into the hair and scalp. Next, after rinsing with water, the hair is dried. For hair oil or hair serum which is a leave-on hair care composition, it is left as it is for 1 to 10 hours after application and then rinsed off.

[0100] The present invention will be further illustrated by the following non-limiting examples, in which all percentages are by weight based on the total weight unless otherwise indicated.

[0101] The present invention is not limited to the embodiments shown in the drawings. Therefore, when reference numerals follow the features described in the claims, it should be understood that such numerals are included only for the purpose of enhancing the understanding of the claims and in no way limit the scope of the claims. The examples are intended to illustrate the present invention and are not intended to limit the present invention to those examples themselves.

Example

[0102] Example 1: Preparation of a composition (fine particles) outside the scope of the present invention (Reference 1) 1 gram of Octopirox® was dissolved in 12.5 g of molten cetostearyl alcohol at 70 °C to form a clear solution. Then, 86.5 g of DI water was placed in a 250 mL beaker and heated to 70 °C with stirring. To this water, the solution of Octopirox® in cetostearyl alcohol was added while homogenizing at 2000 rpm for 15 minutes. The system was gradually cooled to room temperature while stirring. Then, the evaporated water was replenished until 100 g of slurry remained (13.5% solids content, i.e., fine particles). The particle size of the fine particles was 70 μm.

[0103] Example 2: Preparation of a composite material within the scope of the present invention (Reference 2) 3 grams of chitosan was dissolved in 300 mL of 0.5% aqueous acetic acid to form a 1% chitosan solution. 1 gram of Octopirox® was dissolved in 12.5 g of molten cetostearyl alcohol at 70 °C to form a clear solution.

[0104] Subsequently, 62.5 g of the 1% chitosan acetate solution and 24 g of DI water were mixed in a beaker at 70 °C. The Octopirox® solution was heated to 70 °C and added to the contents of the beaker while homogenizing at 2000 rpm for 15 minutes. The system was gradually cooled to room temperature while stirring. Then, water was replenished until 100 g of slurry remained (14% solids content, i.e., microparticles). The particle size of the microparticles was 54 μm.

[0105] Example 3: Preparation of a composite material within the scope of the present invention (Reference 3) A 1% solution of chitosan acetate was prepared as previously disclosed. 1 gram of Octopirox® was dissolved in 12.5 g of molten cetostearyl alcohol and 4 g of damascone at 70 °C to form a clear solution.

[0106] Subsequently, 62.5 g of the 1% chitosan acetate solution and 20 g of DI water were mixed in a beaker at 70 °C. The Octopirox® solution was heated to 70 °C and added to the contents of the beaker while homogenizing at 2000 rpm for 15 minutes. The system was gradually cooled to room temperature while stirring. Then, water was replenished until 100 g of aqueous slurry remained (18% solids content, i.e., microparticles).

[0107] The particle size of the microparticles was 43 μm.

[0108] Example 4: Preparation of a composite material within the scope of the present invention (Reference 4) A 1% solution of chitosan acetate was prepared as previously disclosed. 1 gram of Octopirox® was dissolved in 8.5 g of molten cetostearyl alcohol and 4 g of damascone at 70 °C to form a clear solution.

[0109] Thereafter, 62.5 g of 1% chitosan acetate solution and 24 g of DI water were mixed in a beaker at 70°C. The Octopirox® solution was heated to 70°C and added to the beaker while homogenizing at 2000 rpm for 15 minutes. The system was gradually cooled to room temperature while stirring. Then, water was replenished until 100 g of slurry remained (14% solids content, i.e., fine particles). The particle size of the fine particles was 36 microns.

[0110] The details of the compositions of Examples 1 to 4 are summarized in Table 1.

Table 1

[0111] The compositions of Examples 1 to 4 were subjected to various tests described below.

[0112] Example 5: Adhesion effectiveness The degree of adhesion of Octopirox® (on the scalp) contained in the fine particles was evaluated by formulating a series of shampoo compositions 1A to 4A each containing a certain amount of fine particles from Examples 1 to 4. In other words, Shampoo 1A contained the fine particles of Example 1, and so on.

[0113] The formulation is shown in Table 2.

Table 2

[0114] The degree of adhesion of Octopirox® to the scalp was confirmed as follows.

[0115] A piece of model skin (2 cm × 2 cm × 4 mm) was placed in a Petridish®. 375 mg of the shampoo (under evaluation) was added thereto. Subsequently, the skin piece and another blank skin piece (untreated) were immersed in 10 mL of methanol and dispersed by ultrasonic treatment for 10 minutes. 1 mL of the methanol solution was passed through a 0.2 μm PTFE filter and transferred into a liquid chromatography (LC) sample vial for LC analysis to obtain the adhesion amount data D 0 was obtained.

[0116] A piece of model skin (2 cm × 2 cm × 4 mm) was placed in a Petridish®. 375 mg of the shampoo (under evaluation) was added thereto. Subsequently, the skin piece of the shampoo was gently rubbed with another skin piece (untreated) for 30 seconds, and the two skin pieces were rinsed with 250 mL of water. Then, the rinsed skin pieces were immersed in 10 mL of methanol and dispersed by ultrasonic treatment for 10 minutes. 1 mL of the methanol solution was passed through a 0.2 μm PTFE filter and transferred into a liquid chromatography (LC) sample vial for LC analysis to obtain the adhesion amount data D.

[0117] Subsequently, the adhesion effectiveness was calculated according to the following formula. [Equation 1] Octopirox adhesion effectiveness = D / D 0 × 100%.

[0118] The data is summarized in Table 3.

Table 3

[0119] The data in Table 3 shows that the adhesion rate (%) provided by the compositions (fine particles) outside the scope of the present invention (Example 5 and Example 1A) is not as good as the degree of adhesion observed in the case of Examples 2A to 4A.

[0120] Example 6 The purpose of this experiment was to confirm the degree of stability of Octopirox (registered trademark) contained in the fine particles of Examples 1 to 4 in the shampoo composition. It was evaluated by examining how much of the Octopirox (registered trademark) contained in the fine particles leaked into the shampoo base. In this test, Shampoo Product 5 and Shampoo Products 1A to 4A were used immediately after preparation. This test was repeated after storing the composition for 1 day, 7 days, and 14 days.

[0121] In this experiment, the shampoo products were prepared by mixing 4 grams of fine particle slurry (Examples 1 to 4 as appropriate) with 16 g of shampoo base in 50 mL centrifuge tubes. Therefore, the formulation of the shampoo for the purpose of this experiment was different from the formulations (1A to 4A) disclosed in Table 2. To avoid ambiguity in naming, the sample reference numbers used in this experiment were named 1B to 4B.

[0122] The shampoo samples were stored at room temperature for 1 day, 7 days, and 14 days. At a predetermined time, 20 g of deionized water was added to the centrifuge tube (containing 20 g of shampoo), and the tube was centrifuged at 10,000 rpm for 20 minutes. Then, the liquid portion (supernatant) was collected for UV analysis to examine the concentration of Octopirox (registered trademark) therein, which was expressed as the percentage of loss compared to the amount of Octopirox (registered trademark) in the newly prepared shampoo product.

[0123] The results are summarized in Table 4.

Table 4

[0124] The data in Table 4 indicate that Octopirox was more stable in the case of Compositions 2B to 4B. However, among these three types, the stability was highest in the case of Example 4B. The fine particles of Example 4 contain a co-solvent (damascone), and this additional stability (or reduction in leakage) may be due to damascone.

[0125] Example 7: Release of Octopirox (registered trademark) from microcapsules into sebum For this experiment, the slurry of Example 4 was lyophilized to obtain a powder. 7 mg of this powder was incubated in 2 mL of a model sebum composition maintained at 32 °C in an oven. At a predetermined time, the mixture was taken out of the oven and passed through a 0.2 μm PTFE filter to remove insoluble substances. The filtrate was dispersed in methanol and transferred into an LC sample vial for LC analysis. Another 7 mg of the same powder was directly dissolved in methanol, and the concentration of Octopirox® was measured by LC. This sample was for comparison purposes (control) and for the 100% release sample. Subsequently, the percentage of Octopirox® released from the composite material was calculated.

[0126] The results showed that at 32 °C, approximately 90% of Octopirox® was released from the composite material of Example 4 into sebum. In other words, this observation indicates that the composite material according to the present invention is sufficiently stable inside the composition, but at the same time, the composite material can release Octopirox® when in contact with sebum, and due to this property, the composite material is suitable for use in hair care products such as shampoos.

[0127] Example 8 A 1% solution of chitosan acetate was prepared as previously disclosed. 1 gram of Octopirox® was dissolved in 8.5 g of molten lauryl alcohol (MP 24 °C) and 4 g of damascone at 40 °C to form a clear solution.

[0128] Subsequently, 62.5 g of chitosan acetate solution and 24 g of DI water were measured at 40 °C and placed into a beaker. The Octopirox® solution was heated to 40 °C and added to the beaker while homogenizing at 2000 rpm for 15 minutes. The system was gradually cooled to room temperature while stirring. Thereafter, the evaporated water was replenished to obtain 100 g of an aqueous slurry.

[0129] It was possible to prepare the microparticles in this way, but when the temperature exceeded 24 °C, the composite material turned into a liquid, indicating that the microparticles were not thermally stable.

[0130] Example 9 A 1% solution of chitosan acetate was prepared as previously disclosed. 1 gram of Octopirox® was dissolved in 8.5 g of molten Fischer-Tropsch wax (Sasolwax® H1, MP 112 °C) and 4 g of damascone at 120 °C to form a clear solution.

[0131] Subsequently, 62.5 g of the 1% chitosan solution and 20 g of DI water were measured at 100 °C and placed into a beaker. The Octopirox® solution was heated to 120 °C and added to the beaker while homogenizing at 2000 rpm. The Octopirox® solution immediately solidified and was unable to form fine composite particles.

Claims

1. Composite particles comprising: (i) An anti-dandruff agent which is piroctone olamine; (ii) A wax-like substance in which the anti-dandruff agent is soluble or dispersible, wherein the melting point of the wax-like substance is 30°C to 105°C; and (iii) 10 ３ Da to 10 ７ A cationic polymer having a weight average molecular weight of Da; wherein the composite particles have a particle size of 0.1 to 1000 μm, wherein the cationic polymer is chitosan or derivatized chitosan, and wherein the wax-like substance is a C13-35 fatty alcohol, said composite particles.

2. The composite particles according to claim 1, wherein the composite particles contain 0.1 to 80% by weight of the anti-dandruff agent, 18 to 95% by weight of the wax-like substance, and 0.5 to 10% by weight of the cationic polymer.

3. The composite particles according to claim 1 or 2, further comprising a co-solvent in which the anti-dandruff agent is soluble or dispersible, wherein the co-solvent is a ketone and wherein the co-solvent is not the wax-like substance.

4. The composite particles according to claim 3, wherein the co-solvent is a ketone selected from 2-hexanone, 2-octanone or damascone.

5. The composite particles according to claim 3 or 4, wherein the composite particles contain 0.2 to 30% by weight of the co-solvent.

6. The composite particles according to any one of claims 1 to 5, wherein the zeta potential of the cationic polymer is +10 to +100 mV.

7. The composite particles according to any one of claims 1 to 6, wherein the composite particles are in powder form or in the form of an aqueous suspension.

8. A method for preparing the composite particles according to claim 1, comprising the steps of heating and stirring an aqueous slurry containing the wax-like substance and the anti-dandruff agent, and subsequently adding the cationic polymer to the slurry and further heating the slurry at 30 to 100°C for 5 to 60 minutes.

9. A hair care product comprising the composite particles according to any one of claims 1 to 7.

10. The hair care product according to claim 9, wherein the hair care product contains the composite particles according to any one of claims 1 to 7 in an amount such that the total amount of the anti-dandruff agent in the hair care product is 0.01 to 5.0% by weight. ​

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