Formulation and In-Vitro Characterization of Acyclovir Floating Matrix Tablets: A Factorial Design Study

The objective of present study was to develop controlled release floating matrix tablets of Acyclovir using combination of release retarding polymers: hydroxypropyl methylcellulose (HPMC K15M CR) and polyethylene oxide (Polyox WSR 303) for treatment of herpes infections using direct compression technique. The influence of type of polymer and its concentration on the drug release from prepared floating tablets was investigated using a 32 factorial design. Independent variables selected were concentration of Polyox WSR 303 (X1) and HPMC K15M CR (X2) while dependent variables were percentage cumulative drug release at 3, 9 and 12 h (Q3, Q9, and Q12). Analysis of variance (ANOVA) and multiple regression analysis showed significant effect on Q3, Q9, and Q12. Formulations also contained sodium bicarbonate (NaHCO3) and anhydrous citric acid as floating agent, polyvinyl pyrrolidone (PVP K30) as dry binder and microcrystalline cellulose (MCC, Avicel PH 102) as diluent. The floating tablets were evaluated for their floating lag time (FLT), floating duration, hardness, friability, weight variation, and in-vitro drug release, dissolution efficiency and accelerated stability study. F2 with Polyox WSR 303 (50 mg) and HPMC K15M CR (15 mg) gave best results. Stability study revealed optimized formulation F2 to remain stable. A controlled release floating matrix tablet of Acyclovir was successfully prepared by using Polyox WSR 303 and HPMC K15M CR.