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CA-3000880-C - A SKIN LIGHTENING COMPOSITION

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Abstract

The present invention is in the field of personal care compositions; in particular skin lightening compositions. It is believed that niacinamide reduces the melanosome transfer from melanocytes to keratinocytes thereby bringing about skin lightening. However, niacinamide is known to have little or no effect directly on the melanin content in the melanocytes. Thus a composition with multiple modes of action,that combines the reduction of melanosome transfer and the reduction of melanin content in the melanocytes remains to be desired. It is therefore an object of the present invention to provide a composition with synergistic amounts of picolinamide and niacinamide, providing improved melanosome transfer inhibition. It has been found that a synergistic skin lightening effect is obtained when niacinamide is combined with its isomer, picolinamide.

Inventors

  • Anita Damodaran
  • Manoj Kumar JOSHI
  • Balu Kunjupillai
  • Rezwan Shariff

Assignees

  • UNILEVER PLC

Dates

Publication Date
20260505
Application Date
20161004
Priority Date
20151005

Claims (8)

  1. 18 Claims 1. A skin lightening composition comprising: a 0.1 to 10% by weight of picolinamide; and b 0.1 to 10% by weight of niacinamide wherein the composition comprises picolinamide and niacinamide in such amounts to achieve a synergistic skin lightening effect; wherein the mole ratio of picolinamide to niacinamide is in the range of 4:1 to 1 :8.
  2. 2. The skin lightening composition according to claim 1, wherein the composition comprises 1 to 5% by weight of picolinamide.
  3. 3. The skin lightening composition according to claim 1 or 2, wherein the composition comprises 1 to 5% by weight of niacinamide.
  4. 4. The skin lightening composition according to any one of claims 1 to 3, further comprising a skin benefit agent.
  5. 5. The skin lightening composition as defined in any one of claims 1 to 4 in the form of a topical composition.
  6. 6. Use of the composition as defined in any one of claims 1 to 5 for skin lightening.
  7. 7. Use of the composition as defined in any one of claims 1 to 5 for applying onto skin of a human for lightening the skin.
  8. 8. Use of the composition as defined in any one of claims 1 to 5 in the manufacture of a composition for applying onto skin of a human for lightening the skin. Date Re9ue/Date Received 2024-04-15

Description

1 A SKIN LIGHTENING COMPOSITION Field of the invention The present invention is in the field of personal care compositions; in particular skin 5 lightening compositions. Background of the invention Most people are concerned with the degree of pigmentation of their skin. For example, people with age spots or freckles may wish such pigmented spots to be less pronounced, 10 while others may wish to reduce the skin darkening caused by exposure to sunlight or to lighten their natural skin colour. To meet this need, many attempts have been made to develop products that reduce the pigment production in the melanocytes. However, the substances identified thus far tend to have either low efficacy or undesirable side effects, such as, for example, toxicity or skin irritation. Therefore, there is a continuing need for 15 new cosmetic skin lightening agents, with improved overall effectiveness. Conventional skin lightening compositions are based on the use of skin lightening agents that are believed to control dispersion of melanin or inhibit tyrosinase. These skinlightening agents include niacinamide, carboxylic acids like azelaic acid and kojic acid, 20 plant extracts, hydroquinone etc. Niacinamide is one of the widely used skin lightening agents in compositions for topical application. Niacinamide is the amide form of vitamin B3 (Niacin). Vitamin B3 is an essential watersoluble vitamin and is found in the form of niacin or niacinamide in a wide variety of food 25 including meat, fish, legumes, nuts, grains, mushrooms, yeast & coffee. It is implicated in various cellular functions like DNA repair, keratinocyte differentiation, lipid synthesis, pigmentation and inflammation, most important of them being in cellular bioenergetics. Niacinamide in the form of pyridine nucleotide, nicotinamide adenine dinucleotide (NAD) is important for energy metabolism. A diet deficient in B3 leads to disease called Pellagra 30 characterized by skin conditions with dermatitis and pigmentation. This was the observation that led to the discovery of niacinamide as a skin lightening agent four decades ago. 2 It is believed that niacinamide reduces the melanosome transfer from melanocytes to keratinocytes thereby bringing about skin lightening. However, niacinamide is known to have little or no effect directly on the melanin content in the melanocytes. 5 A composition with multiple modes of action, that combines the reduction of melanosome transfer and the reduction of melanin content in the melanocytes remains to be desired. WO 2013/030794 relates to skin and/or hair depigmentation compositions comprising a pyridine derivative and dermatologically acceptable carriers. This document discloses 10 picolinamide, preferably in a concentration of 0.001 to 30% by weight. WO 2013/030794 further discloses that the composition may include a skin and/or hair benefit agent from a list of agents including nicotinamide. It is therefore an object of the present invention to provide a composition with synergistic 15 amounts of picolinamide and niacinamide, providing improved melanosome transfer inhibition. It is a further object of the invention to achieve a high melanosome transfer inhibition at low concentration of actives. It is a further object of the invention to achieve a reduction of melanin content in the melanocytes at lower concentration of actives. Without wishing to be bound by a theory, it is thought that although picolinamide, is not 25 a precursor for NAO+, it may have an effect on the various processes involved in pigmentation. Without wishing to be bound by theory, it is thought that unlike niacinamide which has shown to affect the melanosome transfer, picolinamide has an effect on the melanin 30 production with little or no effect of melanosome transfer. The invention thus relates to a composition comprising a synergistic combination of niacinamide and picolinamide for use in skin lightening. 3 It has been found that a synergistic skin lightening effect is obtained when niacinamide is combined with its isomer, picolinamide. Summary of the invention 5 Accordingly, in a first aspect, the invention provides a skin lightening composition comprising 0.1 to 10% by weight of picolinamide; and 0.1 to 10% by weight of niacinamide. In a second aspect, the invention provides use of the composition according to the 10 invention for skin lightening. In a third aspect, the invention provides a method of lightening the skin of a human, the method comprising the step of applying the composition according to the invention onto the skin. 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 utilised in any other aspect of the invention. The word "comprising" is 20 intended to mean "including" but not necessarily "consisting of" or "composed o