Taguchi method-based optimization of key parameters for the preparation of poly(lactic-co-glycolic acid) microspheres to enhance betamethasone acetate loading

This study presents an investigation into the effects of key process parameters on the encapsulation of betamethasone acetate (BA) in poly(lactic-co-glycolic acid) (PLGA) microspheres. The Taguchi method was employed to identify the most influential factors affecting microsphere characteristics. The experimental design included variation of several parameters: PLGA concentration, BA concentration, the aqueous-to-organic phase ratio and stirring speed. The results indicate that BA loading is primarily influenced by its own concentration and the polymer concentration. High-performance liquid chromatography was used for determination of betamethasone acetate. Optimal loading was achieved at PLGA and drug concentrations of 100 and 20 mg/mL, respectively, an aqueous-to-organic phase ratio of 50:1, and a stirring speed of 500 rpm. Under these conditions, the drug loading reached 4.35%, compared to 1.44% prior to optimization. These findings may support the refinement of PLGA microsphere preparation techniques for other active pharmaceutical ingredients with similar physicochemical properties.