Ascorbic acid (AA) and caffeine (CAFF) work to protect cells from ultraviolet (UV) radiation and slow down the photoaging process of the skin. However, cosmetic application of AA and CAFF is limited due to poor penetration across the skin and rapid oxidation of AA. The aim of this study was to design and evaluate the dermal delivery of dual antioxidants utilizing microneedles (MNs) loaded with AA and CAFF niosomes. The niosomal nanovesicles were prepared using the thin film method and had particle sizes ranging from 130.6-411.2 nm and a negative Zeta potential of around -35 mV. The niosomal formulation was then combined with polyvinylpyrrolidone (PVP) and polyethylene glycol 400 (PEG 400) to create an aqueous polymer solution. The best skin deposition of AA and CAFF was achieved with the formulation containing 5% PEG 400 (M3) and PVP. Furthermore, the role of AA and CAFF as antioxidants in preventing cancer formation has been well-established. Here we validated the antioxidant properties of ascorbic acid (AA) and caffeine (CAFF) in a novel niosomal formulation referred to as M3 by testing its ability to prevent H2O2-indued cell damage and apoptosis in MCF-7 breast cancer cells. Results showed that M3 was able to shield MCF-7 cells from H2O2 induced damage at concentrations below 2.1 µg/mL for AA and 1.05 µg/mL for CAFF, and also exhibited anticancer effects at higher concentrations of 210 µg/mL for AA and 105 µg/mL. The formulations were stable for two months at room temperature in terms of moisture and drug content. The use of MNs and niosomal carriers could be a promising approach for dermal delivery of hydrophilic drugs like AA and CAFF.
Keywords: antioxidant; ascorbic acid; caffeine; microneedles; niosomes; permeation; polymers.