Microemulsion composed of combination of skin beneficial oils as vehicle: Development of resveratrol-loaded microemulsion based formulations for skin care applications

[Display omitted] •Microemulsions based on combination of multiple skin beneficial oils were developed.•Microemulsion area varied depending on the composition of surfactant and oil phases.•Resveratrol-loaded stable microemulsions and microemulsion-gels were fabricated.•Resveratrol release and skin permeation from the gels exhibited desirable results.•The formulations can be used as skin care products with multiple skin care benefits. Microemulsion can be a potential delivery vehicle to deliver skin care actives to deep skin layer for chronic skin care benefits. On top of skin care active, microemulsion vehicle composed of multiple skin beneficial oils can deliver additional skin care efficacies. In this study, microemulsions were developed using combinations of two skin beneficial oils, tea tree oil and medium chain triglyceride instead of single oil. For that, pseudo ternary phase diagrams were constructed on these oil combinations at different ratios of surfactant/co-surfactants. Ratio of oils and surfactant/co-surfactant combinations exhibited significant impact on the microemulsion region. A few compositions were selected from the single phase microemulsion regions of these phase diagrams for the preparation of resveratrol-loaded microemulsion and microemulsion gel formulations. The particle size of the resveratrol-loaded microemulsions were