Development and Optimization of Microballoons Assisted Floating Tablets of Baclofen

The objective of the present study was to develop microballoons aided gastro-retentive floating tablets of baclofen, a skeletal muscle relaxant with a low elimination half-life of ~ 3.5 h. Baclofen floating tablet was prepared to offer convenience by designing a tablet that would float in the stomach for a prolonged period and allow controlled drug release to enable once-a-day administration. Ethylcellulose microballoons (ECMBs) prepared by pseudo emulsion solvent diffusion method were employed as floating aid. The ECMBs were spherical with a size of 446.71 µm and a circularity index of 0.995. Buoyancy of 98.90 percent and good flowability reflected by an angle of repose of 23° suggested the feasibility of preparing floating tablets by direct compression. Directly compressed baclofen floating tablets comprised ECMBs, HPMC-K15M, and hydroxyl ethylcellulose as independent variables in the Box-Behnken design, however, performance characteristics of tablets such as in vitro drug release, floating lag time, and swelling index were selected as the dependent variables. Among the variables, ECMBs played a critical role in ensuring buoyancy. However, HPMC-K15M significantly influenced in vitro drug release. The optimized batch displayed Hickson-Crowell kinetics and exhibited a similar drug release profile as a marketed once-a-day formulation (f₂, 91.03). Furthermore, optimized tablets showed a swelling index of > 300, floating lag time < 3 s, and total floating time > 24 h. Microballoons assisted floating tablets exhibited great promise for assured gastric retention of tablets.