Development and Optimization of Gellan Gum-Based Gastro-Retentive Microbeads for Enhanced Controlled Release of Acyclovir.

Abstract

Modified release systems offer enhanced spatial and temporal control over drug delivery, leading to better blood plasma profiles, targeted therapy, reduced side effects, and improved patient compliance. Recent advancements focus on using biocompatible polymers to achieve sustained or controlled drug release, particularly for gastroretentive systems that enhance oral bioavailability and minimize dose-dependent toxicity. This study explores the formulation of floating microbeads of acyclovir (ACV) using various hydrophilic polymers. The prototype oral formulations demonstrated superior micrometric properties, including bulk density, tapped density, Carr’s index, Hausner’s ratio, angle of repose, average particle size, yield, and drug content. In-vitro dissolution studies revealed controlled release characteristics, with optimal floating time and entrapment efficiency achieved using specific concentrations of olive oil and polymers. Drug release trailed the Korsmeyer-Peppas model, indicating a diffusioncontrolled mechanism. The formulations exhibited good storage stability, in-vivo floating ability, and higher bioavailability in rabbits compared to ACV solutions. The results suggest that hydrophilic polymers are effective for formulating floating microbeads with controlled release and reproducible profiles.