Quality by Design (QBD) Assisted Formulation and Development of Microsphere by Design of Expert (DOE) Approach

Abstract

This study presents the formulation and development of microspheres containing beta-sitosterol. The pH of beta-sitosterol was found to be 7.2, which is within the acceptable range specified for the drug. Its melting point was observed between 160°C and 174°C, aligning with the expected pharmaceutical specifications. A double-beam UV-Visible spectrophotometer (Shimadzu-1700) was used to determine the compound's absorption maxima (λmax), which was found to be 203.0 nm. Eudragit S 100 (polymer) and Tween 80 (surfactant) were selected for further study. Scanning electron microscopy (SEM) at 3,000x magnification revealed that the microspheres were spherical with a smooth surface and a porous structure. Particle size and zeta potential were measured using a Malvern Zetasizer. The analysis confirmed the nanoparticles were in the nanoscale range, with an average particle size of 430.7 nm. The zeta potential of -25.1 mV indicated good stability of the microsphere formulation. The optimized formulation also showed high drug entrapment efficiency, reaching 88.93%. These findings suggest that the Design of Experiments (DOE) approach, guided by the principles of Quality by Design (QbD), is effective for optimizing formulation and process parameters in the development of beta-sitosterol-loaded microspheres.