Comparative physicochemical stability and clinical anti-wrinkle efficacy of transdermal emulgel preparations of 5% sodium ascorbyl phosphate and or ascorbic acid on human volunteers.

OBJECTIVES: Antioxidant containing cosmeceuticals are commonly prescribed products in treating wrinkles and revitalizing the skin. The aim of this study was the comparative evaluation of physicochemical stability and clinical anti-wrinkle efficacy of transdermal emulgel preparations of sodium ascorbyl phosphate (SAP) and ascorbic acid (AA) on human volunteers. METHODS: Emulgel preparations containing 5% of (SAP) and or (AA) were prepared. HPLC analysis was performed for stability evaluations. Clinical anti-wrinkle efficacy of the formulations was examined on human healthy volunteers in crow's feet area. Elasticity and digital images were recorded before and after treatment. RESULTS: Formulations with added antioxidants and kept in the refrigerator exhibited better stability characteristics. Two-sided blind study and placebo-controlled study showed that both actives were effective in wrinkles depth reduction and also elasticity enhancement but statistically significant difference in the efficacy of the products was not observed. CONCLUSION: Formulations containing (AA) and or (SAP) both improved elasticity and wrinkles of the skin almost by the same extent, and it is necessary to add antioxidant stabilizing agents to both preparations to reach a desired stability.