Open-Label Study to Evaluate the Efficacy of a Topical Anhydrous Formulation with 15% Pure Ascorbic Acid and Ginger as a Potent Antioxidant

Abstract

Vitamin C is one of the naturally occurring antioxidants capable of reducing or preventing skin photoaging. Achieving a stable formulation with the optimal dose of ascorbic acid to ensure a biologically significant antioxidant effect is a challenge when developing cosmetic formulations. The objective of this study was to develop a stable formula in a non-aqueous media with 15% pure vitamin C supplemented with ginger and to study its efficacy, skin tolerance, and cosmetic assessment in 33 women. Vitamin C stability over time was determined via a high-performance liquid chromatography (HPLC) technique versus an aqueous option. Reactive oxygen species (ROS) determination was quantified to provide antioxidant effect. A 56-day in vivo study was performed to evaluate skin luminosity and hyperpigmentation reduction. Skin acceptability was verified by a dermatologist. The HPLC studies demonstrated a high stability of the anhydrous formula compared to an aqueous option. The in vitro studies showed a reduction in ROS of 93% (p-value < 0.0001). In vivo, luminosity increased by 17% (p-value < 0.0001) and skin tone became 10% more uniform (p-value < 0.007). Moreover, very good skin tolerance was determined as the dermatologist did not determine any clinical signs, and the subjects did not report any feelings of discomfort. We were able to develop an anhydrous formula of pure vitamin C that combines very good stability, consumer acceptance, and skin tolerance with a high level of efficacy.