Adapalene-loaded transfersome gel containing vitamin C as a combination therapy for the management of acne vulgaris was developed in the present study. The transfersome was prepared by reverse-phase evaporation, and the effect of various process parameters were investigated by the Design of Experiment (DOE) approach and optimized based on the particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The selected tranfersomes were further evaluated for their thermal behavior and morphology by transmission electron microscopy and turbidity measurements and incorporated into a gel with/without vitamin C. The gel was evaluated and compared with the marketed product (Adiff gel) for various physicochemical parameters, and in vivo studies in testosterone-induced rat models of acne. The prepared transfersomes had PS in the range of 280 to 400 nm, PDI values of 0.416 to 0.8, ZP of - 38 to - 20 mV, and % EE of 32 to 70%. DSC studies confirmed a positive interaction of the components in the transfersome. Surface morphology confirmed that the vesicles were spherical, unilamellar, and discrete. A relative deformability study showed higher elasticity of the transfersomes compared with Adiff aqs gel. Ascorbyl-6-palmitate in adapalene-loaded transfersome gel containing vitamin C (ADVTG) was found to have a good antioxidant free radical-scavenging activity. An in vitro drug release study showed that the sustained release of the transfersomal formulations was attributed to the flexibility of the vesicles by which penetration was increased. ADVTG was found to be promising in treating acne compared with the marketed product. Graphical Abstract.
Keywords: Transfersomes; adapalene; cosmetics; topical; vitamin C.