Transparent scalp care composition

Abstract

The present invention relates to a transparent scalp care composition comprising 0.01 to 0.5 wt% of piroctone olamine, 3 to 10wt% sorbic acid based nonionic surfactant, 1 to 20 wt% polyhydric glycol; and 60 to 90 wt% water.

Description

[0001] TRANSPARENT SCALP CARE COMPOSITION

[0002] Field of the Invention

[0003] This invention relates to a transparent scalp care composition. The invention more particularly relates to a personal care composition for hair and scalp that may be used as a leave-on composition without the need of being rinsed off.

[0004] Background of the Invention

[0005] Hair care compositions generally provide cleansing or conditioning benefits or a combination of the two. Such compositions typically comprise one or more cleansing surfactants which generally aid in cleaning the hair and / or the scalp free of undesirable soil, particles, and fatty matter. Additionally, anti-dandruff benefit has been provided through hair care compositions. Dandruff is an issue that affects many people globally. The condition is manifested by the shedding of clumps of dead skin cells from the scalp. These are white in colour and provide an aesthetically displeasing appearance. A factor that contributes to dandruff are certain members of the Malassezia yeasts (a type of fungus). To combat these, anti-dandruff products have been developed in the form of hair cleansing shampoos. An example of a known anti-dandruff shampoo comprises sodium lauryl ether sulfate (an ethoxylated anionic surfactant) in combination with an anti-dandruff agent.

[0006] Typical anti-dandruff agents used in hair care are metal pyrithione e.g. zinc pyrithione (ZPTO), octopirox (piroctone olamine), azole antimicrobials (e.g. climbazole), selenium sulfide and combinations thereof. However, there are several drawbacks of using shampoo compositions to deliver these active ingredients such as the short contact time of the shampoo with the scalp, and the potential irritation of the scalp by the shampoo formulation. It would be desirable to provide one or more anti-dandruff agents in a leave-on hair styling composition to provide a more gentle and efficacious way to treat the scalp for dandruff and / or seborrheic dermatitis. For example, harsh surfactants used in shampoos can be eliminated, and conditioning and soothing ingredients can easily be incorporated into the hair styling composition if desired.

[0007] Furthermore, when a composition comprising an antidandruff active has been attempted as a leave-on, it has been difficult to formulate a composition with consumer desired parameters such as the scalp care composition being too thick, feeling too heavy or oily on hair. A transparent leave-on composition also gives a perception of being mild and hypoallergic to the consumers which helps in acceptance by the consumers as compared to the well-known irritation effects of the anti-dandruff actives.

[0008] Piroctone olamine (also known as Octopirox(R)) is a compound often used in the treatment of fungal infections. Piroctone olamine is the ethanolamine salt of the hydroxamic acid derivative piroctone. Piroctone olamine has anti-fungal properties that make it ideal for controlling the root cause of dandruff, a commonly occurring fungus called Malassezia globosa. It is often used in anti-dandruff shampoo as a replacement for the commonly used compound zinc pyrithione.

[0009] Generally, piroctone olamine is dissolved in the base composition of a shampoo which includes surfactants, water, silicones, polymers and colouring and fragrance ingredients. When a user applies the compositions to hair and scalp, some compound of piroctone olamine get deposited thereon.

[0010] Generally, efficacy of an antidandruff shampoo or conditioner depends on the amount of antidandruff active deposited on the scalp and hair because more deposition means more bioavailability.

[0011] However, the presence of metal salts can reduce the efficacy of piroctone olamine because the deposited piroctone olamine is less bioavailable as piroctone olamine tends to react with metal salts. It is known that the metal salts can be introduced by raw materials and manufacturing, tap water during and after applying the products, and sweat in daily life. Therefore, there is a need to develop products that mitigate this phenomenon and provide higher efficacy.

[0012] Summary of the Invention

[0013] First aspect of the present invention provides a transparent scalp care composition comprising: a. 0.01 to 1.0 wt% of piroctone olamine; b. 1 to 10wt% sorbic acid based nonionic surfactant; c. 1 to 20 wt% of polyhydric glycol; and d. 60 to 90 wt% water.

[0014] Second aspect of the present invention provides use of a composition according to the first aspect, in manufacture of a scalp care composition for reducing scalp dryness and itchiness. Third aspect of the present invention provides use of a method of preventing or reducing growth of M. furfur comprising applying a composition according to the first aspect on a desired skin surface.

[0015] Fourth aspect of the present invention provides a method of preventing or reducing growth of M. furfur in an individual in need thereof, comprising topically applying the scalp care composition according to the first aspect on a desired skin surface.

[0016] Detailed Description of the Invention

[0017] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se.

[0018] Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y.

[0019] When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0020] Throughout the specification unless otherwise specified, wt% means weight % of the total weight of the scalp care composition of the present invention.

[0021] By ‘An antidandruff composition’ as used herein, is meant to include a composition for topical application to skin, hair and / or scalp of mammals, especially humans to eliminate or minimize the population of microorganisms thereon, preferably fungi that are implicated in dandruff. Such a composition is generally applied on to the desired topical surface of the body. It includes any product applied to a human body for also improving appearance, cleansing, odor control or general aesthetics. "Leave-on" as used herein means compositions that are applied to the scalp and / or skin and are not intended to be washed or rinsed off for some period of time, as contrasted with cleansing or wash-off or rinse-off compositions.

[0022] Turbidity, a measure of the cloudiness of a fluid, is recorded in Nephelometric Turbidity Units (NTUs). For the purposes of this invention ‘transparent’ or ‘transparency’ is measured as NTU (Nephelometric Turbidity Units) value of less than 20 preferably when measured by a Turbidimeter.

[0023] "Stable" or "Stability" as used herein means that composition does not separate and is not grainy and does not curdle and does not solidify or form a stiff gel and remains transparent over a period of time.

[0024] A “scalp care composition” is a composition which is intended for application on scalp but also benefits hair.

[0025] The present inventors were faced with the problem of providing a scalp care composition that works to prevent and reduce dandruff and which is transparent even at low temperatures such as at 4°C during winter months and in colder regions of the world. Piroctone olamine is not soluble and stable in the water base formulations. Its crystalized out at low temperature. The composition of the present invention provides a stable formulation to stabilize piroctone olamine in water-based formulation to provide anti dandruff and anti-itching benefit on the scalp. Further if any oil based benefit agents are to be added in the scalp care composition, it further causes the composition to be turbid, even if the composition is attempted to be emulsified, it further contributes to the turbidity. It was a surprizing finding that having the particular ingredients of the present invention when combined in the given weight ranges resulted in a composition that was stable and transparent on storage.

[0026] The composition of the present invention has consumer desirable characteristics as most antidandruff reduction compositions have a rheology which is thick and have an after-feel of stickiness on the hair. Those compositions feel like more of a medication on hair. However, the present composition has a lighter feel, being aqueous, and is perceived to be light and mild, being transparent. The composition of the present invention neither leaves a white residue nor gives a sticky after-feel to the hair which may require a wash. The composition of the present invention has just enough and the right concentration of ingredients to act against M. furfur but yet does not give the feeling that anything has been applied on the hair or scalp. This is a highly desired consumer parameter as the consumer having dandruff mostly has a sensitive and itchy scalp and any scalp application makes them uncomfortable. This problem is effectively solved by the present invention.

[0027] Various components of the composition are described in greater detail below.

[0028] The present invention provides a hair care or a scalp care composition comprising 0.01 to 0.5 wt% of piroctone olamine, 3 to 10 wt% sorbic acid based nonionic surfactant, 1 to 20 wt% polyhydric glycol; and 60 to 90 wt% water.

[0029] The composition of the present invention can be in the form of a liquid, lotion, cream, foam, scrub, gel, or bar. Non-limiting examples of such compositions include wash-off shampoos, shampoo-cum-conditioners, shower gels, hair care liquids or gels or bars. It is most preferable that the composition of the present invention is an aqueous composition for use as a scalp care composition. It is most preferable that the composition is a leave-on composition, which means that it does not require washing off after application.

[0030] The scalp care composition of the present invention is a transparent composition. The composition has a transmittance of 90-99% at 650 nm. The composition has a NTU value of less than 20 when measured by a turbidimeter.

[0031] Malassezia furfur is a species of yeast that is naturally found on the skin surfaces of humans and some other mammals. It is associated with a variety of dermatological conditions caused by fungal infections, notably seborrhoeic dermatitis and tinea versicolor. The composition of the present invention is found to be effective against M. furfur and can be used to reduce its growth. Therefore, the composition of the present invention is effective against dandruff, dry scalp and itchiness and against tinea versicolor.

[0032] The composition of the present invention is targeted to compositions which are substantially free of silicone oils. By the phrase ‘substantially free of silicone oils is meant that silicone oil is present in an amount less than 1.0 percent, preferably less than 0.5 percent, furthermore preferably less than 0.1 percent and optimally absent from the composition. It is most preferred that the composition is free of a silicone compound.

[0033] The silicone oil as per this invention is a silicone compound which is a non-volatile silicone. By non-volatile silicone it is meant that the silicone has a vapor pressure less than 0.1 mm Hg (13.3 Pa), preferably less than 0.02 mm Hg, more preferably less than 0.01 mm Hg at 25 degrees centigrade at one atmospheric pressure.

[0034] Silicone oils as per this invention include polydiorganosiloxanes, in particular polydimethylsiloxanes which have the CTFA designation dimethicone. Also included within this definition are polydimethyl siloxanes having hydroxyl end groups, which have the CTFA designation dimethiconol. Also included within the definition of silicone oils as per this invention are silicone gums having a slight degree of cross-linking, as are described for example in WO 96 / 31188 (UNILEVER).

[0035] Another class of silicones which is substantially excluded from the hair care compositions of the present invention are amino functional silicones. By "amino functional silicone" it is meant a silicone containing at least one primary, secondary or tertiary amine group, or a quaternary ammonium group. Examples of suitable amino functional silicones include: polysiloxanes having the CTFA designation "amodimethicone".

[0036] Antidandruff agent

[0037] The present invention includes an anti-dandruff agent. Anti-dandruff agents present in the hair care composition are compounds that are active against dandruff and are typically antimicrobial agents and preferably antifungal agents. Suitable anti-dandruff agents that may be used in this invention are selected from piroctone olamine (Octopirox(R)), selenium sulfide and mixtures thereof. In a preferred embodiment, the antidandruff agent is piroctone olamine.

[0038] Suitable anti-dandruff agents that may be used in this invention are selected from piroctone olamine (Octopirox(R), ziziphus extract, azole based anti-fungal agents, selenium sulfide and mixtures thereof. The preferred azole based anti-fungal agent is ketoconazole, climbazole or mixtures thereof. Preferably, the anti-dandruff agent is selected from piroctone olamine, ziziphus extract, climbazole and mixtures thereof. In an especially preferred embodiment, the anti-dandruff agent is piroctone olamine and ziziphus extract.

[0039] Typically, the hair care composition of the invention comprises the anti-dandruff agent in an amount of from 0.01 to 5 percent, more preferably from 0.01 to 3 percent, more preferably still from 0.05 to 2 percent, and most preferably from 0.05 to 1.5 percent, based on total weight of the hair care composition and including all ranges subsumed therein. Piroctone olamine

[0040] Piroctone Olamine is an olamine salt of the hydroxamic acid derivative piroctone which is a typical antimicrobial active. It is commonly known as piroctone ethanolamine with the trade name Octopirox(R).

[0041] The piroctone olamine according to the present invention is a 1:1 compound of 1- hydroxy-4- methyl-6-(2,4,4-trimethylpentyl)-2(7 / - / )-pyridinone with 2-aminoethanol and is also designated 1- hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(7 / 7) pyridinone monoethanolamine salt. The CAS number is 68890-66-4 and the compound has the general formula as below:

[0042] Several antidandruff hair care products contain piroctone olamine. It is found that dissolved intact piroctone olamine molecules are the sole bioactive form of piroctone olamine. When a hair care product with piroctone olamine is utilized, the piroctone olamine dissociates and forms a complex with the metal ions (e.g. iron ions, etc) sourced from tap water or sweat, due to which the stability of the bioactive is affected which reduces its antidandruff efficacy.

[0043] The amount of the piroctone olamine in the composition of the invention depends on the type of the hair care composition and the precise nature of other antidandruff agents used. It is preferred that the composition comprises 0.01 to 10 wt percent of said piroctone olamine, more preferably 0.01 to 5 wt percent, furthermore preferably 0.01 to 2 wt percent and further preferably 0.05 to 0.5 wt percent of piroctone olamine and even more preferably 0.1 to 0.3 wt percent and most preferably 0.1 to 0.24 wt percent of piroctone olamine by weight of the composition. Sorbic acid based nonionic surfactant

[0044] The present invention comprises about 2.1 to about 10 wt%, more preferably about 3 to 10 wt% and most preferably about 3 to 8wt% sorbic acid based non-ionic surfactant by weight of the composition. It is most preferred that the surfactant is a polysorbate such as Polyoxyethylene (80) sorbitan monooleate, this polysorbate has the following formula structure:

[0045] Wherein w, x and y are respectively 0 to 20 integers, and z is 1 to 20 integers, and w+x+y+z=4 to 30; and wherein R is straight or branched saturated or unsaturated alkyl; the saturated or unsaturated alkyl having 11 to 23 carbon atoms.

[0046] Polyhydric glycols

[0047] The present invention comprises 1 to 20 wt% polyhydric glycol, more preferably 2 to 18wt% and most preferably 5 to 18wt% by weight of the composition. Preferably the polyhydric glycol is selected from the group of C3 to C6 hydric glycols. It is preferred that at least 80wt% of the total polyhydric glycol is propylene glycol, more preferably at least 90wt% of the total polyhydric glycol is propylene glycol and most preferably the polyhydric glycol is propylene glycol.

[0048] The composition of the present invention is substantially free of glycerin. By the phrase ‘substantially free of glycerin it is meant that glycerin is present in an amount less than 1.0 percent, preferably less than 0.5 percent, furthermore preferably less than 0.1 percent and optimally is absent from the composition. It is most preferred that the composition is free of a glycerin.

[0049] Water

[0050] The present invention is an aqueous composition and comprises 60 to 95 wt% water, preferably 65 to 90 wt% water, more preferably 70 to 90 wt% water and most preferably 80 to 90 wt% water. It is preferable that the compositions of the present invention has at least 60 wt% water, more preferably 65 wt% water, more preferably 70 wt% water and most preferably at least 80 wt% of water.

[0051] Other Ingredients

[0052] Preferably, the composition comprises perfume.

[0053] Preferably, the composition comprises a cosolvent for the perfume. Co-solvents prevent the scattering of light particles that occurs in the composition and thus maintain the transparency of the composition. Preferred co-solvents include alcohols, especially ethanol.

[0054] Preferably, the composition comprises 0.01 to 2wt%, more preferably 0.01 to 2wt%, most preferably 0.8 to 1.2% by weight of thickener. This provides the best rheological properties of the composition. Suitable thickeners are selected from the group of cellulose based polymers, acrylate based polymers and more preferably acrylate based polymers. Most preferably the acrylate based polymers are acrylate cross polymers.

[0055] Preferably, the composition comprises a co-surfactant I co-solvent for the perfume. Cosurfactants also prevent the formulation of light scattering particles and thus maintain the transparency of the composition. Preferred co-surfactants include cremofore as well as Eumulgin HPS, which is composed of coceth-7 and PPG-1 PEG-9 Lauryl glycol ether and PEG- 40 hydrogenated castor oil.

[0056] Preferably, such co-surfactants are included from 0.1 to 3% by weight. Preferably from 1 to 1.5% by weight.

[0057] Preferably, the composition comprises a cationic surfactant. Cationic surfactants provide a hair conditioning benefit.

[0058] Preferably, the composition comprises a fatty material selected from fatty alcohols, fatty acids, fatty amides and fatty esters. Fatty materials provide a hair conditioning benefit.

[0059] Preferably the composition comprises a preservative in the range of 0.1 to 2 wt% by weight of the composition. The preservative can be chosen such that it doesn’t effect the transparency of the composition. Preferred preservatives for the purpose of this invention may be selected from the group of benzoates, phenoxylates, salicylates, chloride based, aromatic ethers etc. and the likes. Compositions according to the present invention may also include some of the known ingredients used in the conditioning sera, which do not impair the overall transparency of the composition. Typical of such ingredients are water miscible silicones, such as certain aminosilicones or silicone polyethers. The composition according to the present invention may be packaged in any suitable packaging, for example a spray, pot, spray bottle etc.

[0060] Mode of Use

[0061] The hair care composition of the invention is primarily intended for topical application to hair and scalp.

[0062] When the composition is a shampoo, it is topically applied to the hair and then massaged into the hair and scalp. Then it is rinsed with water prior to drying the hair.

[0063] It is preferred that scalp care composition is applied topically to the scalp and left for at least 10 minutes, more preferably at least 20 minutes and most preferably at least 30 minutes for effective result in inhibition of M. furfur. The composition is preferably a leave-on composition and does not need a wash or rinse post application.

[0064] The present invention provides a method of preventing or reducing growth of M. furfur comprising applying a composition according to the first aspect on a desired skin surface.

[0065] The present invention provides a method of preventing or reducing growth of M. furfur in an individual in need thereof, comprising topically applying the scalp care composition according to the first aspect on a desired skin surface.

[0066] Process

[0067] The present invention provides a method of preparing a transparent scalp care composition according to the first aspect, the method comprising steps of: a. preparing an aqueous solution of polyacrylate polymer; b. preparing a mixture of polyhydric glycol and anti-dandruff agent, c. mixing the solution from step (a) with the mixture of step (b) to obtain aqueous phase; d. optionally preparing the oil phase with oil soluble components such as essential oils, perfumes, oil soluble anti-dandruff agents; e. Mixing aqueous phase of step (c) and oil phase is present from step (d) to form a solution. f. adding sorbic acid based nonionic surfactant to the solution of step (e) to obtain the scalp care composition of the first aspect.

[0068] The present invention also provides use of a composition according to anyone the first aspect, in manufacture of a scalp care composition for reducing scalp dryness and itchiness.

[0069] The scalp care compositions for the examples were prepared in accordance with the present invention.

[0070] Step 1A- Propylene glycol was taken in a clean beaker and kept under a high shear stirrer. Piroctone olamine was added slowly to it with continuous stirring to avoid lump formation. The process was continued until a transparent clear solution was obtained.

[0071] Step 1B- an oil phase with oil soluble essential oils and other benefit agents was prepared.

[0072] An aqueous solution of acrylate cross polymer was made by stirring, once the solution gained viscosity and became clear and transparent, piroctone olamine and propylene glycol solution prepared in Step 1 A was added slowly to it with continuous stirring. This followed by addition of the oil phase prepared in step 1 B slowly into the solution at low sheer rate. After a few minutes of continuous stirring, preservatives were added with continuous stirring. Finally, polysorbate 80 was added and the solution was stirred for few minutes until it became clear & transparent. Viscosity and pH were adjusted as per spec requirements.

[0073] Transparency was measured by a Turbidimeter (HI88703- Hanna instruments). Calibration of the instrument was performed before conducting the experiment. After calibration of the instruments, well cleaned and dried vials were used for turbidity measurement of the different options of scalp care composition.

[0074] Turbidity data of all samples were recorded at two time points i.e., initially and after one week of storage at 4°C (data is provided in the below table under results section). Table 1

[0075] The data of Table 1 clearly shows that the compositions according to the present invention from E1 to E5 were stable in terms of transparency even at 4°C after one week, whereas the compositions E6 and E7 turned hazy within a week when piroctone olamine levels were raised. In E9 when polysorbate was out of the scope of claimed range or in E10 when propylene glycol was absent the compositions were hazy even at the very start. A value of less than 20NTLI was considered as transparent. In E11 , the wt% of propylene glycol was reduced to 2 wt% by weight of the hair care composition and were found to be hazy even at the very start which further increased in a week’s time. In E12, the composition of E2 was taken and about 1wt% of glycerine was added to it and it was observed that the resultant composition was turbid, which further increased in a week’s time. Therefore, it is clearly evident that there is a critical working wt% range within which the ingredients of the composition are stable and result in a transparent hair care composition. Example 2- Efficacy of scalp care compositions on M. Furfur

[0076] The efficacy of scalp care composition on M. Furfur was measured by Agar Cup Method. Malassezia furfur ATCC 14521 was used for this method and Incubation Conditions were 30°C ±1°C for 72 hours. The Culture Medium was Modified Dixon Agar (MDA).

[0077] Test Suspensions (To be prepared just before use): Prior to the testing the test organism was inoculated on sterile Modified Dixon agar and incubated at 30°C ±1°C for 72 hours. A suspension of the test organism was prepared in sterile saline and the cell density was adjusted to achieve a concentration of approximately ~1 x 107 CFU / ml.

[0078] 10O I of the test organism suspension was swabbed on the surface of dried sterile Modified Dixon Agar. The plate were kept at room temperature for surface drying. Wells with a diameter of 10mm were punched with a sterile cork borer and a volume of 120 l of desired concentration of the test sample was dispensed into the well. The plates were incubated as per given incubation conditions (as mentioned above). After completion of incubation period, plates were checked for the zone of inhibition which is the measure of activity as indicated by a clear circular zone (no growth of the test organism around the well). Diameter of this zone was measured and recorded. The higher the zone of inhibition, the better is the effect of composition on the test organism.

[0079] Table 2-

[0080] The data in table 2 shows that the composition E1 of the present invention is effective in inhibition of Malassezia furfur and thus in reducing the condition of dandruff.

Claims

Claims1. A transparent scalp care composition comprising: a 0.01 to 0.5 wt% of piroctone olamine; b 3 to 10wt% sorbic acid based nonionic surfactant; c 2.5 to 20 wt% glycol; and d 60 to 90 wt% water; wherein the composition comprises less than 1 wt% of glycerine; and wherein the sorbic acid based nonionic surfactant is a polysorbate surfactant.

2. A composition according to claim 1, wherein the polyhydric glycols is selected from the group of C3 to C6 glycols.

3. A composition according to claims 1 or 2, wherein at least 90wt% of the total glycol is propylene glycol.

4. A composition according to any one of the preceding claims 1 to 3, wherein the glycol is propylene glycol.

5. A composition according to any one of the preceding claims 1 to 4, wherein the sorbic acid based nonionic surfactant is polyoxyethylene (80) sorbitan monooleate.

6. A composition according to any one of the preceding claims 1 to 5, wherein the composition is substantially free of glycerine.

7. A composition according to any one of the preceding claims 1 to 6, wherein the composition comprises a thickening agent in the range of 0.08 to 2 wt% by weight of the composition.

8. A composition according to any one of the preceding claims 1 to 7, wherein the composition comprises a preservative in the range of 0.1 to 2 wt% by weight of the composition.

9. A composition according to any one of the preceding claims 1 to 8, wherein the preservative is selected from the group of benzoic acid based preservatives, phenoxy ethanol based preservatives, chlorinated preservatives, phenolic preservatives and the like.

10. A composition according to any one of the preceding claims 1 to 9, wherein the composition is a leave-on composition.

11. A composition according to any one of the preceding claims 1 to 10, wherein the composition has a transmittance of 90-99% at 650 nm.

12. Use of a composition according to any one of the preceding claims 1 to 11 , in manufacture of a scalp care composition for reducing scalp dryness and itchiness.

13. A non-therapeutic method of preventing or reducing growth of M. furfur comprising applying a composition according to any one of the preceding claims 1 to 11 on a desired skin surface.

14. A non-therapeutic method of preventing or reducing growth of M. furfur in an individual in need thereof, comprising topically applying the scalp care composition according to any one of the preceding claims 1 to 11 on a desired skin surface.

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