Stability evaluation of tocopheryl acetate and ascorbyl tetraisopalmitate in isolation and incorporated in cosmetic formulations using thermal analysis

In view of the increase in the number of cosmetic preparations containing antioxidant vitamins, chiefly, due to their action in preventing the process of skin aging, there is a need to develop pre-formulation studies and to validate analytical methods in order to obtain high quality products. Thus, the objective of this research was to evaluate and compare the thermal behavior of tocopheryl acetate and ascorbyl tetraisopalmitate as raw materials, and incorporated into a base cream. Thermogravimetry (TG / DTG) and differential scanning calorimetry (DSC) were used for this purpose. Both vitamins were found to be stable up to 250 C. The base cream (placebo) and the sample (base cream containing the vitamins) presented different weight loss. Thermal analysis has shown it self to be an excellent tool for the characterization of these vitamins and can be used in routine analysis for quality control of this type of cosmetic formulation.