DEVELOPMENT AND OPTIMIZATION OF POLYHERBAL PHYTOSOMES CONTAINING CITRUS LIMON, PONGAMIA PINNATA, AND PHYLLANTHUS NIRURI USING BOX BEHNKEN DESIGN

Abstract

The present study aimed to develop and optimize a phytosomal formulation containing the ethanolic extracts of Citrus limon, Pongamia pinnata, and Phyllanthus niruri using a Quality by Design (QbD) approach with Box Behnken Design (BBD). Three formulation variables, namely phospholipid concentration, cholesterol concentration, and sonication time, were optimized to achieve minimum particle size and maximum entrapment efficiency. Thirteen experimental formulations were prepared and evaluated. Among them, the optimized formulation (PF10) exhibited a particle size of 158.0 nm, entrapment efficiency of 87.12%, and zeta potential of −38.25 mV, indicating the formation of stable phytosomal vesicles. Transmission electron microscopy confirmed the formation of spherical and uniformly distributed phytosomes. The optimized formulation exhibited sustained in vitro drug release, achieving 93.5% cumulative drug release within 12 h. Drug release kinetics showed the best fit to the Higuchi model (R² = 0.9987), indicating diffusion-controlled release. Stability studies conducted for three months demonstrated only minimal changes in particle size and entrapment efficiency under refrigerated and room-temperature storage conditions, confirming the good stability of the formulation. Overall, the optimized phytosomal formulation showed desirable physicochemical characteristics, high encapsulation efficiency, sustained drug release, and excellent stability, suggesting its potential as an effective phytosomal delivery system for improving the therapeutic performance of the selected herbal extracts.