Design and optimization of levofl oxacin gastroretentive tablets

In the present study, gastroretentive fl oating tablets of levofl oxacin hemihydrate were designed with objective of retention of tablet in acidic pH to improve bioavailability with reduction in dosing frequency. Hydroxypropyl methyl cellulose of different viscosity grades (K4M and K100LV) was used as polymer and sodium bicarbonate as gas generating agent to reduce fl oating lag time. Tablets were prepared by direct compression method. The prepared formulations were evaluated for hardness, friability, weight variation, drug content, swelling index, in-vitro drug release, short-term stability, fl oating lag time and in-vitro buoyancy. A 3 2 factorial design was applied to systematically optimize the drug release profi le. The proportions of release retardant material HPMC K100LV(X 1 ), sodium bicarbonate (X 2 ) were selected as independent variables and t 50% (Y 1 ), and t 70% (Y 2 ) were selected as dependent variables. The promising formulation containing levofl oxacin hemihydrate (100 mg), HPMC K100LV (100 mg) and sodium bicarbonate (80 mg) has t 50% (5.95 h), t 70% (8.52 h) , fl oating lag time was only 10.33 sec and released more than 90% drug in 12 h. This study proved that gastroretentive drug delivery system of levofl oxacin hemihydrate was designed using HPMC K100LV, which provided excellent gastroretentive property, thus improved the bioavailability of drug.