Curcumin Microemulsions: Influence of Compositions on the Dermal Penetration Efficacy.

Background/Objective: This study provided a comparison of the influence of each component of the microemulsion formulation and investigated the impact of varying concentrations of the microemulsion components on curcumin's ability to penetrate the skin using an ex vivo porcine ear model. Methods: Curcumin microemulsions with different compositions were prepared and analyzed for their physicochemical properties. The dermal penetration efficacy of curcumin was evaluated from the different formulations and compared with non-microemulsion formulations. Results: Findings proved that microemulsion formulations improve the dermal penetration efficacy for curcumin when compared with non-microemulsion formulations. The composition of the microemulsion affects the penetration efficacy of curcumin and increases with decreasing oil content and increasing surfactant and water content. The best penetration for curcumin is achieved with a microemulsion that contained 7.7 g of medium-chain triglycerides as the oil phase, 6.92 g of Tween^® 80 and 62.28 g of ethanol as the surfactant mixture, and 23.1 g water. Conclusions: The present study provides a foundational basis for further development of different microemulsion formulations for enhancing the dermal penetration of poorly water-soluble active compounds.