Development and Evaluation of a Broad spectrum Polyherbal Sunscreen formulation using Solid Lipid Nanoparticles of Safranal.

Abstract

UV absorption properties of bioactive agents has led to their screening and development to provide photoprotection. Safranal is one such secondary plant metabolite obtained from Saffron (Crocus sativus) and reported to possess antioxidant and antisolar properties. The objective of this research was to design a suitable delivery system for the topical delivery of Safranal and to develop broad-spectrum polyherbal sun protection cream with mild photoprotection. Safranal-loaded solid lipid nanoparticles (SLN) were formulated using probe sonication technique. The effect of variables like lipid concentration, surfactant concentration, and stirring time was studied using central composite design using Design Expert 7.0 (Stat-Ease, Inc., USA). These SLN were combined with zinc oxide, pearl powder, Pterocarpus santalinus, a natural colorant with skin whitening effect and dispersed in a dermatological acceptable carrier with excellent skin-nourishing properties. Other natural ingredients namely almond oil, hen egg oil, and aloe vera gel were also incorporated due to their sun protection properties. Particle size analysis of prepared SLN revealed the particles in the range of 460-980nm (F9). Entrapment efficiency was found between 88% and 99%. SLN was further characterized by techniques like DSC, FTIR, and TEM. Evaluation of sunscreen cream by transmittance method showed good texture, excellent rheological properties, optimum pH, and stability. The developed product showed broad spectrum of sunscreen protection with SPF 9.22, UV-A ++, and *** Boot Star Rating. The significant inhibitory activity of Safranal on matrix metalloproteinases (MMPs) analyzed by biochemical investigation method and a higher SPF established that this bioorganic molecule is a strong photoprotective agent. Designing solid lipid nanoparticles and incorporation of other traditional ingredients in the recipe augmented its antisolar property and provided an all natural sunscreen.