Formulation and Evaluation of Minoxidil Loaded Submicron Emulsion Based Topical Gel for Treatment of Alopecia

Abstract

Introduction: Alopecia is a benign hair condition that causes reduced hair growth on the scalp and has afflicted populations worldwide. Aim: The present study is designed to formulate and characterize submicron emulsion-based topical gel containing an anti-hypertensive drug like minoxidil to overcome the adverse effects of conventional oral dosage forms & to provide an improved, targetted therapy for the treatment of alopecia. Methods: The minoxidil-loaded submicron emulsion was prepared by aqueous titration method using a suitable combination of Clove oil (oil phase), Tween 20 (surfactant), and Transcutol P (co-surfactant). Results: The maximum submicron emulsion area obtained after constructing pseudo-ternary phase diagrams was found in S\(_{\text{mix}}\) ratio 4:1. The optimized submicron emulsion formulation (M5) exhibited a pH of 5.4 \(\pm\) 0.17, in vitro release of 95.08 \(\pm\) 0.36%, ex vivo permeation of 79.36 \(\pm\) 0.18%, the particle size of 181.3nm with an uniform particle size distribution \((<1)\) and optimum zeta potential (-8.80 mV). The optimized formulation (M5) was then converted to intogel formulation by adding different concentrations (1%, 1.5%, and 2% w/v) of gelling agents like Carbopol 934. Among them, M5\(_{2 w/v}\) was considered to be the optimized gel formulation based on different evaluation studies. The optimized submicron emulsion-based gel formulation also showed an inherited anti-oxidant potential and remained stable for three months at \(4^{\circ}\). Conclusion: The minoxidil-loaded submicron emulsion-based topical gel formulation could be considered a beneficial nano-approach in contrast to other traditional topical dosage forms for treating alopecia.