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EP-4493286-B1 - A SOLID CLEANSING COMPOSITION

EP4493286B1EP 4493286 B1EP4493286 B1EP 4493286B1EP-4493286-B1

Inventors

  • BARNE, SAMEER KESHAV
  • DASGUPTA, ANINDYA
  • SAJI, MAYA TREESA

Dates

Publication Date
20260506
Application Date
20230316

Claims (15)

  1. A solid cleansing composition comprising: a. from 2 to 15 wt% ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulphate, isopropyl ammonium chloride and mixtures thereof; and b. from 2 to 25 wt% one or more carboxylic acids having pKa in the range from 2.5 to 4.5; wherein the pH of 5% solution of the composition is in the range from 2.5 to 6.5.
  2. The composition according to claim 1 wherein the ammonium salt is selected from ammonium chloride, ammonium citrate and mixtures thereof.
  3. The composition according to any one of claims 1 or 2 wherein the carboxylic acid is selected from selected from aromatic carboxylic acids, cyclic carboxylic acids, aliphatic carboxylic acids and mixtures thereof.
  4. The composition according to any one of claims 1 to 3 wherein the carboxylic acid is selected from an aromatic carboxylic acid selected from benzoic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, or an aliphatic carboxylic acid selected from citric acid, lactic acid; and mixtures thereof.
  5. The composition according to any one of claims 1 to 4 wherein the carboxylic acid is benzoic acid.
  6. The composition according to any one of claims 1 to 5 wherein the composition further comprises from 10 to 80 wt% anionic surfactant.
  7. The composition according to claim 6 wherein the anionic surfactant is selected from alkyl sulfate, alkyl sulfosuccinate alky sulfoacetate, alkyl ether sulfate, isethionate, taurateand mixtures thereof.
  8. The composition according to any one of claims 1 to 7 wherein the composition further comprises one or more essential oils selected from thymol, terpineol, carvacrol, eugenol, menthol and mixtures thereof.
  9. The composition according to claim 8 wherein the composition further comprises a structurant selected from silica, talc, kaolinite, bentonite, starch, cellulose, feldspar, mica and mixtures thereof.
  10. The composition according to any one of claims 1 to 9 wherein the composition is the form of a bar.
  11. The composition according to any one of claims 1 to 9 wherein the composition is in the form of a powder or a concentrated powder.
  12. Non therapeutic method of providing antimicrobial effect comprising the steps: a. applying the composition as claimed in any one of claims 1 to 11 on to a surface; and b. optionally, rinsing the surface on to which the composition is applied.
  13. The method as claimed in claim 12 wherein the step of rinsing the surface is carried out within 5 minutes from applying the composition to the surface.
  14. Non therapeutic use of the composition as claimed in any one of the claims 1 to 11 for providing antimicrobial effect.
  15. Use of an ammonium salt as an enhancer of the antimicrobial efficacy of a solid cleansing composition, said cleansing composition comprising carboxylic acid having pKa in the range from 2.5 to 4.5; and wherein the pH of 5% solution of the composition is in the range from 2.5 to 6.5.

Description

Field of the invention The present invention relates to a cleansing composition, related methods and uses, according to the appended claims. Background of the invention WO2018 121946 (Unilever) discloses an antimicrobial composition at the pH of skin. The composition comprises (a) 5 to 40% by weight of an ammonium salt having at least one covalently bonded hydrogen attached to the nitrogen or of an anionic surfactant with ammonium group as counter ion or mixtures thereof; and (b) 0.1 to 20% by weight of a carboxylic acid with pKa value greater than 4.5. See also RU2456022 C1, US 2003/089891 A1, WO 2018/121946 A1. However, the carboxylic acids discussed in the prior art are those with pKa greater than 4.5. Although they provide good antimicrobial efficacy in presence of anionic surfactants system as discussed therein, these acids are medium chain fatty acids that are costly and are associated with odor which is less preferred. Such odor then needs to be tackled with fragrance system which further increases the costs. Therefore, there is need to provide a cleansing composition that overcomes one or more drawbacks of prior art. It has now been found that when carboxylic acids having pKa in the range from 2.5 to 4.5 e.g. benzoic acid, which are easier to incorporate in cleansing compositions without giving rise to odor issues, were combined with ammonium salts e.g. ammonium chloride, synergistic antimicrobial effect was obtained. Moreover, the antimicrobial effect is obtained in short duration like 10 to 30 seconds, e.g. 20 seconds. Summary of the invention In a first aspect, the present invention relates to a solid cleansing composition comprising: a. from 2 to 15 wt% ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulphate, isopropyl ammonium chloride and mixtures thereof; andb. from 2 to 25 wt% carboxylic acid having pKa in the range from 2.5 to 4.5, wherein the pH of 5% solution of the composition is in the range from 2.5 to 6.5. In a second aspect, the present invention relates to a method of providing antimicrobial effect comprising the steps: a. applying the composition of the first aspect on to a surface; andb. optionally, rinsing the surface on to which the composition is applied. In a third aspect, the present invention relates to use of the composition of the first aspect in providing antimicrobial effect. In a fourth aspect, the present invention relates to use of an ammonium salt as an enhancer of the antimicrobial efficacy of a solid cleansing composition, said cleansing composition comprising carboxylic acid having pKa in the range from 2.5 to 4.5; and wherein the pH of 5% solution of the composition is in the range from 2.5 to 6.5. Detailed description of the invention 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. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description 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 " x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as "wt%". The use of any and all examples or exemplary language e.g. "such as" provided herein is intended merely to better illuminate the invention and does not in any way limit the scope of the invention otherwise claimed. For the purpose of the present invention, the terms 'antimicrobial benefit' or 'antimicrobial effect' or 'antimicrobial efficacy', may be used interchangeably and they denote the same meaning. Preferably, 'antimicrobial benefit' or 'antimicrobial effect' or 'antimicrobial efficacy' means reduction in number of microbes e.g. bacteria, fungi, viruses. Such antimicrobial effect is obtained when the composition of the present invention is preferably applied on to a surface that may be an inanimate or animate surface. More preferably, the composition is applied to an animate substrate e.g. human skin. 'Skin' as used herein, preferably means to include skin on any part of the body e.g. face, neck, chest, back, arms, underarms, hands, legs, buttocks and scalp. In a first aspect, the present invention relates to a solid cleansing composition comprising: a. from 2 to 15 wt% ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, amm