Formulation and Evaluation of Sustained Release Gastro-retentive Drug Delivery System of Acyclovir Leading to Enhanced Bioavailability

Objective: The objective was formulation and characterization of low-density gastro-retentive microspheres of Acyclovir (ACV) using hydroxyl propyl methyl cellulose to enhanced retention time and bioavailability.

Materials and Methods: HPMCK4M was used as polymer for forming microspheres and Poly Vinyl Alcohol as stabilizing agent. The microspheres were characterized with respect to their morphology, particle size, encapsulation efficiency, production yield, in-vitro release and pharmacokinetic study in rats. The mean particle size was within range and showed spherical shape.

Results and Discussion: Microspheres were having sufficient entrapment efficiency and floating ability and were directly proportional to the polymer concentration. In-vitro and pharmacokinetic study in rats proved the efficiency of microspheres in sustaining the drug release for 12 hrs as compared to oral suspension of ACV.

Conclusion: The floating microspheres of ACV are potential drug delivery system for the enhancement of oral bioavailability of ACV.