Formulation and optimization of pectin-based emulgel isolated from Abelmoschus esculentus using response surface methodology

Emulgels have emerged as a promising drug delivery system for enhancing the topical delivery of hydrophobic drugs. The present study was designed to formulate and characterize the emulgels prepared by using pectin for topical delivery of econazole nitrate. For this purpose, pectin, a natural gelling agent, was extracted from Abelmoschus esculentus (okra pods). The extracted pectin was thoroughly characterized for its physicochemical and micromeritic properties. The response surface methodology from Design-Expert was used to optimize the emulgel preparation. The optimized formulations (F1, F2 and F3) were thoroughly characterized through particle size (PS) and zeta potential (ZP) measurements, as well as compatibility assessment of various ingredients and drug release profiles. The zeta potential measurements revealed values of - 16.9 +/- 0.467 mV, - 17.9 +/- 0.200 mV and - 13.7 +/- 0.109 mV for F1, F2 and F3, respectively, indicating good formulation stability. Furthermore, the polydispersity index (PDI) values (0.230 +/- 0.005, 0.226 +/- 0.002 and 0.075 +/- 0.059 for F1, F2 and F3, respectively) indicated uniform and stable formulations with minimal particle size variation. Among the formulations, F3 exhibited superior spreadability (14.954 gm.cm/s), crucial for optimal topical application, while F1 displayed the highest viscosity (1360.151 Pa), ensuring better retention on the skin and prolonged drug release. Regarding drug content (%), F3 achieved the highest value (79.091%), highlighting its potential for delivering a higher dosage of econazole nitrate. Overall, this scientifically stringent study demonstrates the suitability of pectin extracted from okra pods for formulating emulgels with favorable characteristics, providing a solid foundation for further exploration and development of topical drug delivery systems.