DESIGN OF AN ENCAPSULATED TOPICAL FORMULATION FOR CHEMOPREVENTION OF SKIN CANCER

This study aims to design resveratrol loaded microemulsion (ME) topical formulation for use in skin cancer. Encapsulation of resveratrol can improve its intrinsic solubility and enhance penetration into the skin for topical use as an alternative to injectablcs. Preformulation studies by DSC and FTIR confirmed the compatibility of chosen excipients with resveratrol. Resveratrol loaded microemulsion was developed using phase diagrams based on oleic acid. labrasol and transcutol P as the oil phase, surfactant and co-surfactant respectively. Optimization was based on the particle size and % drug diffused. Optimized resveratrol loaded microemulsion was transparent and stable without phase separation. Optimized ME had an average particle size of 243 nm, zeta potential -32.9 +/- 2.5 mV and % drug content of 92.216 +/- 1.056. Optimized resveratrol ME was incorporated into a gel base to form a microemulgel that exhibited a spreadability of 34.3 +/- 0.34 gcm/s, the viscosity of 6000 +/- 1.67 cps and sustained in-vitro and ex-vivo drug release. Amount of drug diffused (in-vitro) at the end of 24 h was 98.21 +/- 0.03% from the conventional gel. In comparison, 71.11 +/- 0.47 and 68.15 +/- 0.12 was the % drug diffused from the ME gel. Results of drug retention for both in-vitro as well as ex-vivo permeation study was considerably higher for resveratrol microemulgel than control. Data of antioxidant activity, tyrosinase inhibition. and cytotoxicity in B16F10 melanoma cell line prove that resveratrol loaded ME gel is a promising treatment option for skin cancer chemoprevention.