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EP-4117616-B1 - MIXTURE COMPOSITION COMPRISING GLYCOLIPIDS AND TRIETHYL CITRATE

EP4117616B1EP 4117616 B1EP4117616 B1EP 4117616B1EP-4117616-B1

Inventors

  • Brandt, Kathrin Daniela
  • LIEBIG, Stefan Julian
  • WENK, HANS HENNING
  • SALMINA-PETERSEN, MANUELA
  • TÖLLE, Christoph
  • MUSS, Alina

Dates

Publication Date
20260506
Application Date
20210308

Claims (13)

  1. Composition comprising 0.4 % by weight to 8 % by weight of at least one glycolipid selected from the group of rhamnolipids, glucolipids and sophorolipids, 0.01 % by weight to 14 % by weight, preferably 0.02 % by weight to 11 % by weight, triethyl citrate, and water, where the percentages by weight refer to the total composition, characterized in that the weight ratio of all glycolipids to all triethyl citrate comprised in the composition is in the range of from 5 : 1 to 20 : 1, preferably from 6 : 1 to 15 : 1, particular preferably from 7 : 1 to 12 : 1, and that the pH of the composition at 25 °C is from 4.5 to 7.0.
  2. Composition according to Claim 1, characterized in that the pH of the composition at 25 °C is from 4.8 to 6.6 and particularly preferably from 5.2 to 6.0.
  3. Composition according to at least one of the preceding claims, characterized in that said composition comprises 51% by weight to 95% by weight of diRL-C10C10, where the percentages by weight refer to the sum total of all rhamnolipids present.
  4. Composition according to at least one of the preceding claims, characterized in that said composition comprises 0.5% by weight to 9% by weight of monoRL-C10C10, where the percentages by weight refer to the sum total of all rhamnolipids present.
  5. Composition according to at least one of the preceding claims, characterized in that the weight ratio of all di-rhamnolipids present to all mono-rhamnolipids present is greater than 51:49, particularly greater than 91:9, preferably greater than 97:3, particularly preferably greater than 98:2.
  6. Composition according to at least one of the preceding claims, characterized in that said composition comprises 0.5 to 25% by weight of diRL-C10C12, where the percentages by weight refer to the sum total of all rhamnolipids present.
  7. Composition according to at least one of the preceding claims, characterized in that said composition comprises 0.1% by weight to 5% by weight of monoRL-C10C12 and/or, preferably and 0.1% by weight to 5% by weight of monoRL-C10C12:1, where the percentages by weight refer to the sum total of all rhamnolipids present.
  8. Composition according to at least one of the preceding claims, characterized in that said composition comprises 0.5% by weight to 15% by weight of diRL-C10C12:1, 0.5 to 25% by weight of diRL-C10C12, 0.1% by weight to 5% by weight of monoRL-C10C12 and 0.1% by weight to 5% by weight of monoRL-C10C12:1, where the percentages by weight refer to the sum total of all rhamnolipids present.
  9. Composition according to at least one of the preceding claims, characterized in that said composition comprises at least one preservative selected from the group consisting of p-anisic acid, levulinic acid, lactic acid and citric acid, preferably p-anisic acid, and salts of the aforementioned acids, preferably at a concentration of from 0.01 % by weight to 14 % by weight, preferably from 0.02 % by weight to 11 %, by weight, where the percentages by weight refer to the total composition.
  10. Method for preparing a formulation, preferably a cosmetical or pharmaceutical composition, of glycolipids selected from the group of rhamnolipids, glucolipids and sophorolipids comprising the steps of a) providing a composition comprising 40 % by weight to 70 % by weight, preferably 45 % by weight to 55 % by weight of at least one glycolipid selected from the group of rhamnolipids, glucolipids and sophorolipids, 2.0 % by weight to 14 % by weight, preferably 4.0 % by weight to 11 % by weight, triethyl citrate, and water, where the percentages by weight refer to the total composition, characterized in that the weight ratio of all glycolipids to all triethyl citrate comprised in the composition is in the range of from 5 : 1 to 20 : 1, preferably from 7 : 1 to 15 : 1, particular preferably from 8 : 1 to 12 : 1. b) diluting the composition with at least partially water to a formulation comprising 0.4 % by weight to 8 % by weight of the at least one glycolipid, where the percentages by weight refer to the total formulation, characterized in that the pH of the formulation in method step b) is adjusted to a pH of at 25°C from 4.5 to 7.0.
  11. Method according to Claim 10, characterized in that the pH of the formulation in method step b) is adjusted to a pH of at 25 °C from 4.8 to 6.6 and particularly preferably from 5.2 to 6.0, preferably by adding an organic or inorganic base, preferably in concentrated form.
  12. Use of triethyl citrate to stabilize the foam of an aqueous composition containing at least one glycolipid selected from the group of rhamnolipids, glucolipids and sophorolipids.
  13. Use of triethyl citrate to inverse the dependency of foam stability versus pH in an aqueous composition containing at least one glycolipid selected from the group of rhamnolipids, glucolipids and sophorolipids.

Description

Field of the invention The instant invention relates to a composition comprising Glycolipids and Triethyl Citrate (TEC). Prior art Rhamnolipids are anionic surfactants with unique properties like cleansing characteristics, biodegradability and strong foaming ability. Commercial availability of rhamnolipids increased over the past years across different application areas. In cosmetic applications, the foaming ability of rhamnolipids is of special interest. Fast flash foaming and high foam volumes are indications to the consumers that the product is an efficacious quality product. Anyhow, the foaming behaviour of rhamnolipids is depending on the pH value of the formulation. Ozdemir et al. describe the effect of pH on the surface and interfacial behaviour (Colloids Surf. A 2004, 234, 135-143). One disadvantage of the behaviour described in the state of the art consists in the fact, that a pH as high as pH 7 is required for fast foam creation. At lower pH the foaming ability is decreased. Cosmetic compositions are typically formulated at a pH below 7 down to values like pH 5. Here the foaming ability of rhamnolipids is strongly decreased. To overcome this problem additives can be applied. Non-ionic surfactants like fatty acid alkanolamides are available in the market as foam boosters. These substances can contain traces of nitrosamines and are based on tropical oils. WO2001010391A2 describes the use of alkoxylated carboxylic acid esters as foam boosters. The alkoxylation step leads to measurable 1,4-dioxane levels, which is an unwanted by-product for cosmetic applications. In the cosmetics and personal care sector, triethyl citrate is used as a perfume fixer and as a film for hair sprays and nail polish. It is also used as an active ingredient in deodorants. Triethyl citrate is used as a food additive (E number E1505) amongst others to stabilize albuminous foams, for example as whipping aid for egg white. Description of the invention An object of the present invention was to provide compositions with improved foaming ability of rhamnolipids, especially at cosmetically widely used pH-values, in acidic environment Surprisingly, it has been found that the mixture composition described below is able to achieve the object addressed by the invention. One advantage of the mixture compositions according to the invention is their excellent foaming properties. A further advantage of the mixture compositions according to the invention is their outstanding flash foaming under aqueous conditions. A further advantage of the mixture compositions according to the invention is their exceptionally high foam volume under aqueous conditions. A further advantage of the mixture compositions according to the invention is their low viscosity and therefore simple processability in any desired aqueous surface-active system. A further advantage of the mixture compositions according to the invention is their good skin and hair cleansing properties. A further advantage of the mixture compositions according to the invention is their very good solubilizing efficacy for essential oils at low usage levels. A further advantage of the mixture compositions according to the invention is their mildness and good physiological compatibility, in particular characterized by a high value in the red blood cell (RBC) test. A further advantage of the mixture compositions according to the invention is their good skin feel during and after washing. A further advantage of the mixture compositions according to the invention is that they leave behind a smooth and soft skin feel after washing. A further advantage of the mixture compositions according to the invention is that they can be synthesized free from petrochemical raw materials. A further advantage of the mixture compositions according to the invention is that they can be synthesized free from critical raw materials such as tropical oils. A further advantage of the mixture compositions according to the invention is their outstanding microbiological stability. A further advantage of the mixture compositions according to the invention is that the dependency of foaming ability towards pH is reversed compared to pure glycolipids, especially rhamnolipids. Compositions are claimed comprising 0.4 % by weight to 8 % by weight of at least one glycolipid selected from the group of rhamnolipids, glucolipids, and sophorolipids, 0,01 % by weight to 14 % by weight, preferably 0,02 % by weight to 11 % by weight, triethyl citrate, and water, where the percentages by weight refer to the total composition, characterized in that the weight ratio of all glycolipids to all triethyl citrate comprised in the composition is in the range of from 5 : 1 to 20 : 1, preferably from 6 : 1 to 15 : 1, particular preferably from 7 : 1 to 12 : 1., and that the pH of the composition at 25°C is from 4.5 to 7.0. The "pH" in connection with the present invention is defined as the value which is measured for the relevant composition at 25 °C