Formulation and Characterization of Gastroretentive microsphere of Quetiapine Fumerate

Abstract

Quetiapine fumarate, an atypical antipsychotic drug, was subjected to comprehensive preformulation studies to evaluate its physicochemical properties and suitability for gastroretentive drug delivery. The drug was identified as a white to off-white, odorless crystalline powder with a bitter taste. Solubility studies revealed slight solubility in water and better solubility in organic solvents, indicating the need for formulation strategies to enhance its bioavailability. The melting point (182–184 °C), low loss on drying (1.56%), linear calibration curve obeying Beer–Lambert’s law, and characteristic FTIR peaks confirmed the identity, purity, and stability of Quetiapine fumarate. Gastroretentive microspheres loaded with Quetiapine fumarate were successfully prepared using the solvent evaporation technique by varying the ratios of HPMC and Eudragit RLPO. The prepared formulations (F1–F6) were evaluated for percentage yield, drug entrapment efficiency, buoyancy, floating lag time, particle size, zeta potential, and in-vitro drug release. Among all formulations, F3 emerged as the optimized formulation, exhibiting the highest percentage yield (86.65 ± 0.22%), drug entrapment efficiency (79.88 ± 0.15%), excellent buoyancy (85.6 ± 0.2%), and minimal floating lag time (60 ± 3 s). In-vitro drug release studies demonstrated a sustained release profile over 12 hours, following diffusion-controlled kinetics as indicated by Higuchi and Korsmeyer–Peppas models. Particle size and zeta potential analyses confirmed nanoscale size and good stability of the microspheres. Stability studies conducted as per ICH guidelines revealed no significant changes in physical appearance, drug content, or dissolution behavior. The optimized gastroretentive microspheres of Quetiapine fumarate showed promising characteristics for prolonged gastric retention and controlled drug release, suggesting their potential to enhance bioavailability, therapeutic efficacy, and patient compliance.

Keywords: Gastroretentive microspheres; Quetiapine fumarate; Solvent evaporation method; Controlled drug release; Buoyancy; Stability studies.