Microemulsion-Based Topical Delivery of Coriander Essential Oil: Formulation, Stability, and In Vivo Evaluation for Delaying Skin Photoaging

Premature skin aging results from UVB and UVA radiation, leading to photoaging. Microemulsions facilitate efficient medication penetration into the skin via tiny droplets, as these small particles enhance permeation accessibility. This research paper aimed to produce and analyze coriander essential oil (CEO)-enriched microemulsions for topical application, along with their physical properties and in vivo anti-aging test outcomes.The CEO-based microemulsions, using Tween 80 as the surfactant, are prepared in conjunction with ethanol as the co-surfactant, incorporating CEO as the oil component. A comprehensive series of evaluations was performed on the formulations to determine their droplet size, zeta potential, pH, and viscosity, as well as to conduct TEM analysis, stability testing, and assess anti-aging efficacy through in vivo studies involving a UVB-exposed animal model. The optimized microemulsion droplets exhibited diameters ranging from 238 nm to 267 nm, pH values between 4.70 and 4.89, and viscosities between 75 and 90 cps. The droplet investigation using TEM revealed a uniform distribution of spherical forms. Histopathological findings indicated that microemulsion systems, which include CEO as an active component, safeguard ascorbic acid concentrations in skin tissue while concurrently reducing solar damage to dermal layers and organizing collagen networks. No signs of skin irritation were seen. CEO-loaded microemulsions displayed enhanced stability and provided substantial UVB protection, contributing to the mitigation of skin aging. The research results indicated that the Microemulsion (ME) based delivery system can effectively incorporate CEO into topical ME formulated for age reduction therapy. Future clinical research is necessary to evaluate the appropriateness of the CEO's approach in the cosmetic and dermatological product sectors.