Development of Ionically Crosslinked Microspheres Containing Acyclovir Using Natural Polymers for Sustained Release

Acyclovir is a widely used antiviral agent with limited oral bioavailability, requiring frequent dosing that may lead to increased pharmaceutical burden and patient non-compliance.Developing an environmentally conscious, sustained-release delivery system using natural, biodegradable polymers can mitigate these issues while aligning with green pharmaceutical practices.This study aimed to formulate and evaluate ionically cross linked microspheres using biodegradable natural polymers, sodium alginate and gellan gum and environmentally benign ionic crosslinkers (CaCl and AlCl) to achieve sustained release of acyclovir.Microspheres were prepared by ionotropic gelation using varying polymer and crosslinker concentrations.Six formulations (AC-M1 to AC-M6) were evaluated for particle size, yield, entrapment efficiency, swelling index, surface morphology (SEM), and compatibility (FTIR and DSC).In vitro drug release was assessed over 12 h and fitted to release kinetic models (Zero-order, First-order, Higuchi, Korsmeyer-Peppas).Microspheres displayed smooth, spherical morphology with sizes ranging from 540-710 m.Entrapment efficiencies reached up to 82.1% (AC-M5), with swelling indices between 117.9% and 156.3%.FTIR and DSC confirmed chemical stability.AC-M5 showed sustained drug release over 12 hours and followed First-order kinetics (R > 0.998) and Korsmeyer-Peppas diffusion behavior (n = 0.612-0.753).The use of natural, biodegradable polymers in microsphere development offers a green and sustainable approach to pharmaceutical delivery, reducing dosing frequency and potential pharmaceutical waste.This system demonstrates promising potential for eco-conscious, sustained antiviral therapy.