FR3118869A1 - METHOD FOR IMPROVING THE ANTIOXIDANT ACTIVITY OF VITAMIN C IN AQUEOUS SOLUTION - Google Patents

Abstract

The present invention relates to the field of antioxidant compositions comprising vitamin C. More particularly, it relates to a process for improving the antioxidant activity of vitamin C in aqueous solution, as well as various compositions comprising superactivated vitamin C and their method of preparation. These compositions can be used in particular in the cosmetic, food-processing, nutraceutical or pharmaceutical fields.

Description

METHOD FOR IMPROVING THE ANTIOXIDANT ACTIVITY OF VITAMIN C IN AQUEOUS SOLUTION

The present invention relates to the field of antioxidant compositions comprising vitamin C. More particularly, it relates to a process for improving the activity of vitamin C in aqueous solution, as well as various compositions comprising superactivated vitamin C and their preparation process. These compositions can be used in particular in the cosmetic, nutraceutical, pharmaceutical or food-processing fields.

Vitamin C is a molecule known and used for a long time for its antioxidant properties, in particular for its ability to inhibit free radicals, and therefore oxidative stress. It is more generally found in dry form, pure or mixed with other compounds. In recent years, the dry liposomal form (vitamin C coated with liposome) has been particularly developed to improve its assimilation by the body. Assimilation occurs mainly at the level of the duodenum and the proximal jejunum and is saturable, the percentage absorbed decreasing even with the dose ingested. It is also sodium-dependent and can be inhibited by structural analogs.

The role of vitamin C has also been examined at the cutaneous level. In addition to its antioxidant role, its presence in high concentrations in the skin could be associated with other functions, such as the formation of collagen, the inhibition of the formation of melanomas or the modulation of epigenetic expressions.

The bioavailability of vitamin C varies greatly depending on the method of preparation and assimilation. Thus, depending on the form (dry, liposomal, liquid, emulsified, etc.) and the preparation technique used, the same amount of vitamin C absorbed can lead to:

• Very different assimilation rates;
• Very different activities measured in the body.

Dry forms are widely preferred today, to guard against possible problems of chemical stability (degradation of vitamin C over time), physical (emulsion phase separation for example) or microbiological problems encountered with aqueous solutions. However, it is well known that the assimilation and bioavailability of vitamin C in dry form are not optimal. New products are regularly offered on the market to stand out from the competition with a formulation likely to make vitamin C more active in the broad sense.

It is known to use a treatment for the preparation of stable emulsions comprising a lipid phase in an aqueous phase using piezoelectric transducers. In particular, patent WO2010/149668 describes a method for preparing an oil-in-water emulsion produced in a container in which is immersed a piezoelectric transducer operating at high frequencies, in particular greater than 900 kHz. It has also been proposed in patent WO2017/037372 to use a similar process, using ultrasound at comparable frequencies, to vectorize hydrophobic active ingredients, in the form of a dispersed phase in a hydrophilic continuous phase. In particular, it has been proposed to increase the bioavailability of co-enzyme Q10 by this process.

It is desirable to have new formulations of vitamin C with improved antioxidant activity.

Surprisingly, the inventors have demonstrated that it is possible to increase the antioxidant activity of vitamin C in solution by applying high-frequency ultrasound to this solution.

Thus, the invention relates to a method for improving the antioxidant activity in solution in an aqueous medium consisting in treating said solution with ultrasound at a vibration frequency greater than or equal to 1 MHz.

The invention also relates to a process for the preparation of an aqueous antioxidant composition comprising overactivated vitamin C, said composition being treated by application of the process of the invention, as well as the composition obtained.

The invention also relates to a process for preparing an emulsion comprising overactivated vitamin C, as well as the composition obtained in the form of an emulsion.

Finally, it relates to the use of a composition according to the invention in the cosmetic, nutraceutical and pharmaceutical field.

Advantages of the invention

The main advantage of the process according to the invention is that it makes it possible to increase the antioxidant activity of vitamin C in solution by at least 10%, preferably by at least 20%. This property is quite surprising and very interesting.

The process is particularly interesting because it makes it possible to formulate vitamin C in aqueous solution, that is to say that it makes it possible to prepare a stable liquid aqueous composition of vitamin C without adding stabilizing compounds (without adding active chemical, without texturizing, without emulsifying or any other compound known to stabilize solutions). It paves the way for the preparation of new formulations of vitamin C in aqueous solution. Such formulations can be presented in the form of a glass ampoule or a plastic pod.

Due to an increase in antioxidant activity, the dose of vitamin C can be reduced for the same effectiveness compared to the dose included in the compositions available to date. For the same reason, for the same reference dose (in mg for example), the antioxidant activity will be higher with an overactivated vitamin C as defined in the invention.

The compositions according to the invention give access to new antioxidant formulations which can be used in cosmetics, in nutraceuticals, in pharmaceuticals and in the food industry.

Claims (10)

Process for improving the activity of vitamin C in aqueous solution consisting in treating said solution containing vitamin C by ultrasound at a vibration frequency greater than or equal to 1 MHz. Process for the preparation of an aqueous composition comprising superactivated vitamin C comprising the steps of:

• Dissolution of vitamin C in an aqueous medium
• Treatment of said solution by ultrasound at a vibrational frequency greater than or equal to 1 MHz.

Aqueous composition comprising overactivated vitamin C characterized in that it is obtained by treatment using the process defined in claim 2. Process for the preparation of an oil-in-water type emulsion comprising superactivated vitamin C comprising the steps of:

• Dissolution of vitamin C in an aqueous medium
• Addition of an oily solution in a proportion of between 1% and 30% relative to the molar quantity of the aqueous solution
• Treatment of said solution by ultrasound at a vibrational frequency greater than or equal to 1 MHz.

Method according to claim 4 wherein said oily solution is a vegetable oil, an essential oil or a mixture of oils. Emulsion comprising overactivated vitamin C, characterized in that it is obtained by treatment using the process defined in one of Claims 4 or 5. Cosmetic composition comprising superactivated vitamin C, characterized in that it is obtained by treatment using the process defined in one of claims 2 or 4 and that it comprises, in addition to vitamin C, at least one ingredient chosen among vitamins other than vitamin C, moisturizing agents, depigmenting agents, texturizing agents, pH correctors and coloring agents. Use of a composition as defined in one of Claims 3 or 7 in cosmetics to help regenerate the skin and/or improve its radiance and/or stimulate the formation of collagen. Composition as defined in claim 3 for its use in nutraceuticals to prevent the effects of oxidative stress. Composition as defined in claim 3 for its use as a medicament.