D-OPTIMAL MIXTURE DESIGN ASSISTED FORMULATION OPTIMIZATION OF DESONIDE-LOADED EMULGEL FOR TOPICAL APPLICATION

Objective: This research specifically targets the development of a microemulsion formulation with critical quality attributes, i. e., optimal particle size distribution, drug content, and controlled release characteristics. The aim is to enhance the topical delivery of desonide. Methods: Oil selection was carried out using the phase titration method for determining the appropriate Smix ratio, followed by the construction of ternary phase diagrams. A D-optimal mixture design was employed, considering oil, Smix, and water as independent variables, while particle size, polydispersity index (PDI), zeta potential, % transmittance, and cumulative % drug release (CDR %) as response variables. Results: The optimized microemulsion was clear and transparent with a PS 18 nm, PDI 0.42, zeta potential 13.00mV, and transmittance of 92.25%. This microemulsion was incorporated into a 2% Carbopol 971P gel base. The resulting gel was clear, pH 6.02, with a spreadability of 23.379 g. cm/sec, CDR (%) of 94.03% in 24 h. followed Higuchi drug release kinetics. Ex vivo drug permeation through porcine skin was 27.83 % in 10 h., showing enhanced permeation when compared with the marketed product. Conclusion: The developed gel possessed all desired quality attributes. The data obtained from in vitro and ex vivo studies validated its efficacy as an improved option over conventional products for the treatment of skin diseases.