Method for encapsulating active ingredients

Abstract

The invention relates to a method for producing encapsulated active ingredients, wherein sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is dispersed in water in a first container while being stirred, one or more active substances are dissolved in an oil phase in a second container, the water phase with the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is added to the oil phase while being stirred, resulting in the formation of a Pickering emulsion, and subsequently the Pickering emulsion is heated to at least 58°C for at least 15 minutes, resulting in the surface of the Pickering emulsion being cured.

Description

[0001] Beiersdorf Aktiengesellschaft Hamburg

[0002] Description

[0003] Methods for encapsulating active ingredients

[0004] The present invention relates to a process for the production of encapsulated active ingredients, wherein in a first container sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is dispersed in water under stirring, in a second container one or more active ingredients are dissolved in an oil phase, the aqueous phase containing the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is added to the oil phase under stirring, whereby a Pickering emulsion is formed and subsequently the Pickering emulsion is heated to at least 58 °C for at least 15 minutes, whereby the surface of the Pickering emulsion droplets hardens.

[0005] The desire to look beautiful and attractive is rooted in human nature. Even though the ideal of beauty has changed over time, the pursuit of a flawless appearance has always been a human goal. The condition and appearance of the skin plays a significant role in achieving a beautiful and attractive appearance.

[0006] For the skin to fully perform its biological functions, it requires regular cleansing and care. Cleansing the skin removes dirt, sweat, and dead skin cells, which provide an ideal breeding ground for pathogens and parasites of all kinds. Skin care products primarily moisturize and replenish the skin's natural oils. They often contain active ingredients that regenerate the skin and, for example, prevent and reduce premature aging (such as the formation of fine lines and wrinkles) or protect against the negative effects of UV radiation.

[0007] These active ingredients and UV filters are typically added to preparations in their pure form. This has the disadvantage that they are exposed to environmental influences such as oxidation, UV light (in the case of active ingredients), acids, and microbial degradation. Furthermore, they can interact with other ingredients in the preparation. Finally, their incorporation is limited in quantity, as they are generally insufficiently soluble in the base of the preparation. One way to overcome these disadvantages is to encapsulate the active ingredients and UV filters. However, state-of-the-art encapsulation methods have several drawbacks: Polymeric plastics, such as acrylates, are frequently used as capsule materials. However, these materials are increasingly undesirable due to their slow biodegradability.Furthermore, these polymeric plastics have the disadvantage of being relatively difficult to incorporate into preparations. Above all, the release of active ingredients from these capsules leaves much to be desired. The active ingredients are released only insufficiently. Natural polymers, such as alginates, offer another encapsulation option. However, these materials often provide inadequate protection for the sensitive ingredients (especially against UV light and oxidation). Moreover, the release of active ingredients here, too, repeatedly presents experts with unexpected challenges.

[0008] The object of the present invention was therefore to develop an encapsulation method for active ingredients and UV filters that avoids the use of synthetic polymers. The preparations should be free, in particular, of polyacrylates, polymethacrylates, polyvinylpyrrolidone (PVP), and polyamides. The method should effectively protect the active ingredients and UV filters from environmental influences, facilitate their incorporation into cosmetic formulation bases, and ensure the uncomplicated release of the active ingredients when the preparations are applied to human skin.

[0009] The problems are surprisingly solved by a process for producing encapsulated active ingredients, wherein a) sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is dispersed in water in a first container while stirring, b) one or more active ingredients are dissolved in an oil phase in a second container, c) the aqueous phase containing the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is added to the oil phase while stirring, forming a Pickering emulsion, d) the Pickering emulsion is then heated to at least 58 °C for at least 15 minutes, causing the surface of the Pickering emulsion droplets to harden.

[0010] What is particularly surprising is that the encapsulation is able to prevent the crystallization of the active ingredients. The solubility product can be exceeded, allowing higher concentrations of active ingredient to be incorporated without crystallization occurring over time at various storage temperatures. This applies especially to the active ingredients salicylic acid, (2R,3R)-3,5,7-trihydroxy-2-(3,4,5-trihydroxyphenyl)-2,3-dihydrochromen-4-one (INCI: Dihydromyricetin), / \ / -[4-(2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2-methylpropanamide (INCI: Isobutylamido Thiazolyl Resorcinol), and coenzyme Q10. According to the invention, it is preferred if the Pickering emulsion is heated for at least 20 minutes in step d).

[0011] Furthermore, according to the invention, it is preferred if the Pickering emulsion is heated to 58 °C in step d).

[0012] The method according to the invention is advantageously characterized in that the active ingredients are cosmetic active ingredients.

[0013] For the process according to the invention, it is advantageous in the sense of the present invention if the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is obtained from quinoa starch.

[0014] Advantageous embodiments of the method according to the invention are further characterized in that the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is present in particulate form.

[0015] According to the invention, it is preferred if the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is in particulate form and has an average particle size of 3 pm.

[0016] The sodium starch octenylsuccinate advantageous according to the invention (INCI: Sodium Starch Octenylsuccinate) can be purchased, for example, from Lucas Meyer Cosmetics under the trade name “Pickmulse™”.

[0017] According to the invention, it is advantageous for the process if the water contains sodium chloride in feature a).

[0018] The embodiments preferred according to the invention are characterized in that the water contains sodium chloride in a concentration of 0.3 to 0.5 wt%, based on the total weight of the water.

[0019] Furthermore, it is advantageous in the sense of the present invention if step a) is carried out at 30-40 °C.

[0020] Last but not least, the inventive method in step a) is characterized in that 20 g to 60 g of sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) are dispersed in one liter of water.

[0021] The method according to the invention is suitable for a wide variety of cosmetic active ingredients. In particular, the following groups of active ingredients and oil phases have been identified:

[0022] The first group is characterized by the use of one or more UV light filters as active ingredients, selected from the group of compounds hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI: Diethylamino hydroxy benzoyl hexyl benzoate), 4-(tert-Butyl)- 4'-methoxydibenzoylmethane, 2,4,6-T ris-[anilino-(p-carbo-2'-ethyl-T-hexyloxy)]-1 ,3,5-triazine (INCI: Ethylhexyl Triazone) and 2,4-Bis-{[4-(2-ethyl-hexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (INCI: Bis-Ethylhexyloxyphenol methoxyphenyl Triazine).

[0023] For these UV filters, it is advantageous according to the invention if one or more oils are used for the oil phase, selected from the group of compounds consisting of propylene glycol dibenzoate (INCI: Propylene Glycol Dibenzoate), dipropylene glycol dibenzoate (INCI: Dipropylene Glycol Dibenzoate), neopentyl glycol diheptanoate (INCI: Neopentyl Glycol Diheptanoate), diethylhexyl adipate (INCI: Diethylhexyl Adipate), diethylhexyl succinate (INCI: Diethylhexyl Succinate), ethyl polyglyceryl acetal levuliate (INCI: Ethyl PG Acetal Levuliate), ethyl levulinate (INCI: Ethyl Levulinate), butyl sevulinate (INCI: Butyl Sevulinate), diisopropyl sebacate (INCI: Diisopropyl Sebacate), diisopentyl terephthalate (INCI: Di(iso)pentyl Terephthalate), and dibutyl adiate. (INCI: Dibutyl Adipate), Disiopropyl Adipate (INCI: Diisopropyl Adipate), Neopentyl Glycol Diheptanoate (INCI: Neopentyl Glycol Diheptanoate), Triheptanoin, Butylene Glycol Dicaprylate / Dicaprate (INCI: Butylene Glycol Dicaprylate / Dicaprate),C12-15 Alkyl Benzoate (INCI: C12-15 Alkyl Benzoate), Butylneglycol Dicaprylate (INCI: Butylene Glycol Dicaprylate), Diisooctyl Succinate (INCI: Diisooctyl Succinate), Propylene Glycol Dicaprylate / dicaprate (INCI: Propylene Glycol Dicaprylate / Dicaprate).,

[0024] According to the invention, it is preferred if the UV filter(s) are used in a total concentration of 25 to 50 wt%, based on the total weight of the oil phase.

[0025] A second active ingredient that is advantageous according to the invention is salicylic acid.

[0026] In this case, the method advantageous according to the invention is characterized in that one or more oils are used for the oil phase, which are selected from the group of compounds octyldodecanol, castor oil and isopropyl palmitate.

[0027] In such a case, it is preferred according to the invention if the salicylic acid is used in a concentration of 5 to 25 wt%, based on the total weight of the oil phase.

[0028] A third, advantageous active ingredient according to the invention is (2R,3R)-3,5,7-Trihydroxy-2-(3,4,5- trihydroxyphenyl)-2,3-dihydrochromen-4-one (INCI: Dihydromyricetin).

[0029] According to the invention, it is advantageous for this compound if one or more oils are used for the oil phase, selected from the group consisting of dimethylcapramide (INCI: Dimethyl Capramide), isopropyl lauroyl sarcosinate (INCI: Isopropyl Lauroyl Sarcosinate), dimethyl isosorbide (INCI: Isomethyl Isosorbide), and ethyl levulinate (INCI: Ethyl Levulinate). In this process according to the invention, it is advantageous, within the meaning of the present invention, if (2R,3R)-3,5,7-trihydroxy-2-(3,4,5-trihydroxyphenyl)-2,3-dihydrochromen-4-one (INCI: Dihydromyricetin) is used in a concentration of 1 to 10% by weight, based on the total weight of the oil phase.

[0030] A fourth active ingredient that is advantageous according to the invention is coenzyme Q10.

[0031] In such a case, the embodiments advantageous according to the invention are characterized in that one or more oils are used for the oil phase, which are selected from the group of compounds ethylhexyl stearate (INCI: Ethylhexyl Stearate), ethylhexyl cocoate (INCI: Ethylhexyl Cocoate), isopropyl palmitate (INCI: Isopropyl Palmitate), propylene glycol diheptanoate (INCI: Propylene Glycol Diheptanoate).

[0032] For this method variant according to the invention, it is preferred if coenzyme Q10 is used in a concentration of 1 to 5 wt%, based on the total weight of the oil phase.

[0033] As a fifth, advantageous active ingredient according to the invention, / \ / -[4-(2,4-dihydroxyphenyl)-1 ,3- thiazol-2-yl]-2-methylpropanamide (INCI: Isobutylamido Thiazolyl Resorcinol) could be identified.

[0034] In such a case, the embodiments advantageous according to the invention are characterized in that one or more oils are used for the oil phase, which are selected from the group of compounds Diisopropyl adipate (INCI: Diisopropyl Adipate), Dibutyl adipate (INCI: Dibutyl Adipate), Isopropyl lauroyl sarcosinate (INCI: Isopropyl Lauroyl Sarcosinate).

[0035] According to the invention, it is preferred if / \ / -[4-(2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2- methylpropanamide (INCI: Isobutylamido Thiazolyl Resorcinol) is used in a concentration of 1 to 10 wt%, based on the total weight of the oil phase.

[0036] A preparation produced according to a method according to the invention is also included in the invention.

[0037] Furthermore, according to the invention, a method for producing active ingredient particles is characterized in that the solid particles produced according to the method described above are separated from the preparation.

[0038] According to the invention, it is preferred if the solid particles are filtered or centrifuged from the preparation.

[0039] According to the invention, a cosmetic preparation also includes a preparation according to the invention, a preparation produced according to the invention, and / or solid particles according to the invention. It is preferred according to the invention that all preparations, processes, and solid particles according to the invention are free of polyacrylates, polymethacrylates (PMMA), and polyamides.

[0040] It is also preferred according to the invention for all preparations, processes and solid particles according to the invention that the preparations are free of polyethylene glycol, polyethylene glycol ethers, polyvinylpyrrolidone (PVP) and polyethylene glycol esters (so-called PEG derivatives), polyvinylpyrrolidone (PVP), parabens, methylisothiazolinone, chloromethylisothiazolinone and DMDM ​​hydantoin.

[0041] According to the invention, it is particularly preferred for all preparations, processes and solid particles according to the invention that the preparations are free of alginates.

[0042] Examples

[0043] The following examples are intended to illustrate the present invention without limiting it. Unless otherwise stated, all quantities, proportions, and percentages are based on the weight and total quantity or total weight of the preparations.

[0044] The following Pickering emulsions were produced:

[0045] Production of the Pickering emulsion and encapsulation

[0046] To prepare the aqueous phase, water is placed in a beaker, and sodium chloride is dissolved in it while stirring. The starch (Pickmulse) is then added to the aqueous phase and thoroughly dispersed with the Ultraturrax T25 at room temperature for 2 minutes. To keep the temperature below 40°C, the aqueous phase is placed in a cold water bath.

[0047] To prepare the emollients, the emollients are placed in a beaker and the active ingredient is dissolved at 60°C while stirring (magnetic stirrer) until completely dissolved. The emollients are then cooled while stirring (magnetic stirrer) until they reach below 40°C.

[0048] Now we add the cooled emollients to the water phase while homogenizing with the Ultraturrax T25 for 3 minutes. To prevent the temperature from exceeding 40°C, a cold water bath is used. A Pickering emulsion forms.

[0049] The water bath is then heated until the Pickering emulsion reaches a temperature of 58 ± 2°C while stirring at 150 rpm. This temperature is maintained for 15 minutes and then cooled back to room temperature. Stirring is continued at 150 rpm during this time.

[0050] The encapsulation process is now complete, and the preparation (hereinafter referred to as "slurry") can be further processed to produce a cosmetic preparation. Cosmetic preparations using the "slurry"

Claims

Patent claims 1. A method for the production of encapsulated active ingredients, wherein a) in a first container sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is dispersed in water under stirring, b) in a second container one or more active ingredients are dissolved in an oil phase, c) under stirring the aqueous phase containing the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is added to the oil phase, forming a Pickering emulsion, d) the Pickering emulsion is then heated to at least 58 °C for at least 15 minutes, causing the surface of the Pickering emulsion droplets to harden.

2. Method according to claim 1, characterized in that the active ingredients are cosmetic active ingredients.

3. Method according to one of the preceding claims, characterized in that the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is obtained from quinoa starch.

4. Method according to one of the preceding claims, characterized in that the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is in particulate form.

5. Method according to one of the preceding claims, characterized in that the sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) is in particulate form and has an average particle size of 3 pm.

6. Method according to one of the preceding claims, characterized in that the water contains sodium chloride.

7. Method according to one of the preceding claims, characterized in that the water contains sodium chloride in a concentration of 0.3 to 0.5 wt%, based on the total weight of the water.

8. Method according to one of the preceding claims, characterized in that step a) is carried out at 30-40 °C.

9. Method according to one of the preceding claims, characterized in that 20g to 60g of sodium starch octenylsuccinate (INCI: Sodium Starch Octenylsuccinate) are dispersed in one liter of water.

10. A method according to one of the preceding claims, characterized in that the active ingredients are one or more UV light filters selected from the group consisting of the compounds hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI: Diethylamino hydroxybenzoyl hexyl benzoate), 4-(tert-Butyl)-4'-methoxydibenzoylmethane, 2,4,6-tris-[anilino-(p-carbo-2'-ethyl-T-hexyloxy)]-1,3,5-triazine (INCI: Ethylhexyl Triazone) and 2,4- Bis-{[4-(2-ethyl-hexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl)-1 ,3,5-triazine (INCI: Bis- Ethylhexyloxyphenol methoxyphenyl Triazine) can be used.

11. A method according to one of the preceding claims, characterized in that one or more oils are used for the oil phase, selected from the group consisting of the following compounds: propylene glycol dibenzoate (INCI: Propylene Glycol Dibenzoate), dipropylene glycol dibenzoate (INCI: Dipropylene Glycol Dibenzoate), neopentyl glycol diheptanoate (INCI: Neopentyl Glycol Diheptanoate), diethylhexyl adipate (INCI: Diethylhexyl Adipate), diethylhexyl succinate (INCI: Diethylhexyl Succinate), ethyl polyglyceryl acetal levuliate (INCI: Ethyl PG Acetal Levuliate), ethyl levulinate (INCI: Ethyl Levulinate), butyl sevulinate (INCI: Butyl Sevulinate), diisopropyl sebacate (INCI: Diisopropyl Sebacate), diisopentyl terephthalate (INCI: Di(iso)pentyl Terephthalate). Dibutyladiate (INCI: Dibutyl Adipate), Disiopropyl adipate (INCI: Diisopropyl Adipate), Neopentyl glycol diheptanoate (INCI: Neopentyl Glycol Diheptanoate), Triheptanoin, Butylene glycol dicaprylate / dicaprate (INCI: Butylene Glycol Dicaprylate / Dicaprate),C12-15 Alkyl Benzoate (INCI: C12-15 Alkyl Benzoate), Butylneglycol Dicaprylate (INCI: Butylene Glycol Dicaprylate), Diisooctyl Succinate (INCI: Diisooctyl Succinate), Propylene Glycol Dicaprylate / dicaprate (INCI: Propylene Glycol Dicaprylate / Dicaprate)., 12. Method according to one of the preceding claims, characterized in that the UV filter(s) are used in a total concentration of 25 to 50 wt%, based on the total weight of the oil phase.

13. Method according to one of claims 1 to 9, characterized in that salicylic acid is used as the active ingredient.

14. Method according to claim 13, characterized in that one or more oils are used for the oil phase, which are selected from the group consisting of the compounds octyldodecanol, castor oil and isopropyl palmitate.

15. Method according to one of claims 13 and 14, characterized in that the salicylic acid is used in a concentration of 5 to 25 wt%, based on the total weight of the oil phase.

16. Method according to any one of claims 1 to 9, characterized in that (2R,3R)-3,5,7-Trihydroxy-2-(3,4,5-trihydroxyphenyl)-2,3-dihydrochromen-4-one (INCI: Dihydromyricetin) is used as the active ingredient.

17. Method according to claim 16, characterized in that one or more oils are used for the oil phase, which are selected from the group consisting of the compounds dimethylcapramide (INCI: Dimethyl Capramide), isopropyl lauroyl sarcosinate (INCI: Isopropyl Lauroyl Sarcosinate), dimethyl isosorbide (INCI: Isomethyl Isosorbide), and ethyl levulinate (INCI: Ethyl Levulinate).

18. Method according to one of claims 16 and 17, characterized in that (2R,3R)-3,5,7-Trihydroxy-2-(3,4,5-trihydroxyphenyl)-2,3-dihydrochromen-4-one (INCI: Dihydromyricetin) is used in a concentration of 1 to 10% by weight, based on the total weight of the oil phase.

19. Method according to one of claims 1 to 9, characterized in that coenzyme Q10 is used as the active ingredient.

20. Method according to claim 19, characterized in that one or more oils are used for the oil phase, which are selected from the group consisting of the compounds ethylhexyl stearate (INCI: Ethylhexyl Stearate), ethylhexyl cocoate (INCI: Ethylhexyl Cocoate), isopropyl palmitate (INCI: Isopropyl Palmitate), propylene glycol diheptanoate (INCI: Propylene Glycol Diheptanoate).

21. Method according to one of claims 19 and 20, characterized in that the coenzyme Q10 is used in a concentration of 1 to 5 wt%, based on the total weight of the oil phase.

22. Method according to one of claims 1 to 9, characterized in that / V-[4-(2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2-methylpropanamide (INCI: Isobutylamido Thiazolyl Resorcinol) is used as the active ingredient.

23. Method according to claim 22, characterized in that one or more oils are used for the oil phase, which are selected from the group of compounds Diisopropyl adipate (INCI: Diisopropyl Adipate), Dibutyl adipate (INCI: Dibutyl Adipate), Isopropyl lauroyl sarcosinate (INCI: Isopropyl Lauroyl Sarcosinate).

24. Method according to one of claims 22 and 23, characterized in that N-[4- (2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2-methylpropanamide (INCI: Isobutylamido Thiazolyl Resorcinol) is used in a concentration of 1 to 10 wt%, based on the total weight of the oil phase.

25. Preparation, manufactured according to a method according to any one of claims 1 to 24.

26. Method for producing active ingredient particles, characterized in that the solid particles produced according to a method of claims 1 to 24 are separated from the preparation.

27. Method according to claim 26, characterized in that the solid particles are filtered or centrifuged from the preparation.

28. Cosmetic preparation comprising a preparation according to claim 25, a preparation produced according to a method according to any one of claims 1 to 24 and / or solid particles according to any one of claims 25 and 26.

29. Preparations, processes and solid particles according to any of the preceding claims, characterized in that the preparations are free of polyacrylates, polymethacrylates (PMMA) and polyamides.

30. Preparations, processes and solid particles according to any of the preceding claims, characterized in that the preparations are free of polyethylene glycol, polyethylene glycol ethers, polyvinylpyrrolidone (PVP) and Polyethylene glycol esters (so-called PEG derivatives), polyvinylpyrrolidone (PVP), parabens, methylisothiazolinone, chloromethylisothiazolinone and DMDM ​​hydantoin.

31. Preparations, processes and solid particles according to any of the preceding claims, characterized in that the preparations are free of alginates.

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