Formulation and in-vivo evaluation of a cosmetic multiple emulsion containing vitamin C and wheat protein.Pak J Pharm Sci. 2008 Jan; 21(1):45-50.PJ
The purpose of the study was to see the effect of two antiaging agents in one stable multiple emulsion prepared using natural oil. Vitamin C, which is a very unstable ingredient and is decomposed in the presence of oxygen, active as an antioxidant, was entrapped in the inner aqueous phase of w/o/w multiple emulsion. In this way, slow release can be expected and the effect of vitamin C can be increased since it is protected from the external environment by entrapping it in the internal phase. The other ingredient which is a product of wheat proteins was also used as an antiaging agent in the oily phase. Both of the ingredients increase the synthesis of collagen fibers in the dermis. Therefore, a synergystic effect can be produced by using the two ingredients in one formulation. In this study, multiple emulsions were prepared by the two-step method. Basic formulation containing no active material and a stable formulation containing vitamin C in the internal aqueous phase and wheat protein in the oily phase were prepared. The oil used was macadamia nut oil since it contains a high quantity of palmitoleic acid which is the natural ingredient of the young skin. Basic formulation as well as the active formulation after confirming their stabilities, were applied to the cheeks of 11 human volunteers for four weeks. Different parameters of the skin were monitored every week to see any effect produced by these emulsions. The data obtained was evaluated statistically. It was found that the active formulation as well as base increased the moisture of the skin as verified by statistical tests. However, there were no significant variations in other parameters like skin sebum, pH, elasticity, melanin and erythema, concerning the two formulations.