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EP-4734933-A1 - COSMETIC COMPOSITION

EP4734933A1EP 4734933 A1EP4734933 A1EP 4734933A1EP-4734933-A1

Abstract

A cosmetic composition is disclosed comprising i) hinokitiol; and ii) a hydroxamic acid; wherein the weight ratio of the amount of said hydroxamic acid to that of hinokitiol is from 2:1 to 15:1; wherein the hydroxamic acid is caprylhydroxamic acid, benzohydroxamic acid or a mixture thereof.

Inventors

  • CHIU, CHUNG-CHING
  • PU, Mingming
  • WANG, Zongxiu

Assignees

  • Unilever IP Holdings B.V.
  • UNILEVER GLOBAL IP LIMITED

Dates

Publication Date
20260506
Application Date
20240527

Claims (14)

  1. 1. A cosmetic composition comprising i) hinokitiol; and ii) a hydroxamic acid; wherein the weight ratio of the amount of said hydroxamic acid to that of hinokitiol is from 2:1 to 15:1 ; wherein the hydroxamic acid is caprylhydroxamic acid, benzohydroxamic acid or a mixture thereof.
  2. 2. A composition as claimed in claim 1 wherein the weight ratio of the amount of said hydroxamic acid to that of hinokitiol is from 2.5:1 to 15:1 , preferably from 3:1 to 13.5:1, more preferably from 5:1 to 13.5:1.
  3. 3. A composition as claimed in claims 1 or 2 wherein the hydroxamic acid is caprylhydroxamic acid.
  4. 4. A composition as claimed in any of claims 1 to 3 wherein the composition comprises from 2ppm to 2% of hinokitiol by weight of the composition.
  5. 5. A composition as claimed in any of claims 1 to 4 wherein the composition comprises from 13ppm to 10% of said hydroxamic acid by weight of the composition.
  6. 6. A composition as claimed in any of claims 1 to 5 wherein the composition comprises a cosmetically acceptable carrier comprising water.
  7. 7. A composition as claimed in any of claims 1 to 6 wherein the composition is a rinse-off or leave-on composition, preferably rinse-off composition.
  8. 8. A composition as claimed in any of claims 1 to 7 wherein the composition comprises a cleansing surfactant.
  9. 9. A composition as claimed in claim 8 wherein said cleansing surfactant comprising an anionic surfactant, preferably alkyl sulphates or alkyl ether sulphates, more preferably sodium lauryl ether sulphate.
  10. 10. A composition as claimed in any of claims 1 to 9 wherein said composition is a hair care composition, preferably a shampoo.
  11. 11. A composition as claimed in any of claims 1 to 10 for use in the treatment of dandruff by providing synergistic antimicrobial benefit against Malassezia spp on a topical surface of a human or animal body.
  12. 12. A composition as claimed in any of claims 1 to 10 for use in the treatment of against at least some Malassezia spp on a topical surface of a human or animal body.
  13. 13. A composition as claimed in any of claims 1 to 10 for use in the treatment of preventing or alleviating the symptoms of dandruff on the scalp or hair.
  14. 14. A non-therapeutic method of providing synergistic antimicrobial benefit against Malassezia spp on a topical surface of a human or animal body comprising a step of applying a safe and effective amount of a cosmetic composition as claimed in any of claims 1 to 10.

Description

COSMETIC COMPOSITION Field of the Invention This invention relates to cosmetic compositions, preferably rinse off compositions, more preferably hair care compositions. More particularly the invention relates to cosmetic compositions that comprise hinokitiol and a hydroxamic acid. Background of the Invention Hinokitiol is a tropolone originally isolated from the heart wood of T. plicata that has diverse biological activities, including antifungal, antibacterial, and antiproliferative properties. Hinokitiol has been used in oral, hair and skin care products. Generally, hinokitiol is dissolved in the base composition of a product which includes surfactants, water, polymers and colouring and fragrance ingredients. When a user applies the compositions to hair, oral or skin, compound of hinokitiol get deposited thereon. Hydroxamic acids, represented by the general formula RC (O)NR’OH, exhibit a wide spectrum of biological activity, and can be used as antifungal agents, antimicrobials. Dandruff control is an important aspect of hair cleansing and care. Anti-dandruff benefit has been provided through hair care compositions including shampoos and hair conditioners. 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 is certain members of the Malassezia yeasts. To combat these, anti-dandruff products have included certain antidandruff agents which have anti-fungal activity, for example, piroctone compound such as piroctone olamine. These anti-dandruff agents remove (or at least reduce the level of) the Malassezia from the scalp and provide moderately effective treatment of the dandruff condition. Such a product performs as a hair cleansing shampoo or as a hair conditioner while mitigating the causes of dandruff. There remains a need to provide an improved antimicrobial efficacy onto the surface of skin/scalp, upon applying the products. The present inventors have now found unexpectedly that the combination of hinokitiol and a hydroxamic acid with certain ratio can provide synergistic antimicrobial efficacy onto a topical surface of a human or animal body, preferably on skin/scalp. Summary of the Invention In a first aspect, the present invention is directed to a cosmetic composition comprising: i) hinokitiol; and ii) a hydroxamic acid; wherein the weight ratio of the amount of said hydroxamic acid to that of hinokitiol is from 2:1 to 15:1 ; wherein the hydroxamic acid is caprylhydroxamic acid, benzohydroxamic acid or a mixture thereof. In a second aspect, the present invention is directed to a cosmetic composition of the first aspect for use in the treatment of dandruff by providing synergistic antimicrobial benefit against Malassezia spp on a topical surface of a human or animal body. In a third aspect, the present invention is directed to a cosmetic composition of the first aspect for use in the treatment of against at least some Malassezia spp on a topical surface of a human or animal body. In a fourth aspect, the present invention is directed to a cosmetic composition of the first aspect for use in the treatment of preventing or alleviating the symptoms of dandruff on the scalp or hair. In a fifth aspect, the present invention is directed to a non-therapeutic method of providing synergistic antimicrobial benefit against Malassezia spp on a topical surface of a human or animal body comprising a step of applying a safe and effective amount of a cosmetic composition of the first aspect. All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow. Detailed of the Invention Cosmetic By ‘a cosmetic composition’ as used herein, is meant to include a composition for topical application to skin, hair and/or scalp of mammals, especially human beings. Such a composition is generally applied on to the desired topical surface of the body for a period of time from a few seconds to up to 24 hours. When the period of time of application is low say of the order of a few seconds to a few minutes after which the composition is rinsed off with water or wiped away, such a composition is known as a cleansing composition or a wash-off composition. On the other hand, When the composition is applied for longer period of time say from several minutes to up to 24 hours and washed off usually during the process of normal personal cleaning, such a composition is known as a leave-on composition. The composition as per the present invention includes any product applied to a human body for also improving appearance, cleansing, odor control or general aesthetics. Hair Care Composition “Hair care composition”, as used herein, is meant to include a composition for topical application to hair and/or scalp of mammals, especially humans. Such a composition