Design, formulation, and evaluation of hydrogel network based microbeads for prolonged release of valacyclovir

Background: This study aimed to formulate and develop hydrogel network-based microbeads for the prolonged release of the antiviral drug Valacyclovir, focusing on the effect of natural gum/polymer ratios in their preparation. Methodology: Microbeads containing Valacyclovir hydrochloride were prepared using the ionotropic gelation method, which involved sodium alginate and gellan gum as the polymers, and aluminum chloride as the crosslinking agent. Result: In the evaluation, the F1 batch exhibited the highest swelling capacity, drug entrapment efficiency, and drug release profile. Across all formulations, the particles were round to oval in shape, with sizes ranging from 598 to 816µm. Drug release kinetics revealed that the Higuchi model best explained the formulations. The surface morphology of the best-performing formulation was examined using scanning electron microscopy (SEM). Discussion: The findings proposed that the prepared microbeads function as swellable matrix-type systems, enabling prolonged drug delivery. The Higuchi model fit supported a diffusion-controlled release mechanism, while the SEM analysis confirmed the suitability of the microbead structure for sustained release applications. Conclusion: These kinds of ionotropically-gelled alginate-based microbeads may improve patient compliance by reducing dosing frequency and enhancing oral bioavailability.