Microencapsulation of retinyl palmitate by melt dispersion for cosmetic application

Retinyl palmitate was encapsulated in wax matrix by melt dispersion for the purpose of economic and sustainable cosmeceutical formulation with minimum use of synthetic chemicals. We evaluated the effect of different process variables of microencapsulation by melt dispersion. In this study, a three level definitive screening design was applied, where the microcapsule properties were analysed through statistical analysis to understand the effect of four process variables: type of wax, theoretical loading capacity, surface concentration and stirring speed. Microparticles were characterised for size using image analysis; loading capacity and encapsulation efficiency using ultraviolet-visible spectroscopy; antioxidant activity through DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Melt dispersion method was effective to produce microcapsules with a spherical shape and mean size as small as 28 µm. The encapsulation efficiency ranged 60-80%. Theoretical loading capacity (p-value = 0.00232, significance level, α = 1%) and surfactant% (p = 0.0573, α = 10%) were found to be the most significant factors to control the actual loading capacity and size of microcapsules.