FORMULATION AND EVALUATION OF LEVOFLOXACIN HEMIHYDRATE SUSTAINED RELEASE TABLET FROM HYDROPHILIC MATRICES

Stable sustained release tablets of levofloxacin hemihydrate were successfully prepared by wet granulation technique. Compatible excipients were selected and different formulations were prepared with varying proportion and grades of hydroxy propyl methyl cellulose. Tablets were prepared by compressing free flowing granules and evaluated for hardness, thickness, friability, weight variation, percentage drug content and drug release. As concentration of HPMC increased the drug release decreased might be due to increased amount of polymer around tablets provided gelation which inhibits the release. For formulation F5 only 55 % drug was released in 8 h whereas up to 90 % drug was release for formulation F2 and F3 within the same time. Thus, higher viscosity HPMC retards the drug release directly than lower viscosity HPMC. All the formulations follow Higuchi model which has indicated that drug release from homogenous matrix was through diffusion. Thus, increase in concentration of polymer decreases the drug diffusion from tablet.