Development and Evaluation of Gastroretentive Floating Drug Delivery System of Atenolol

Atenolol, an antihypertensive drug, has poor bioavailability (40-50%) and has has low elimination half life(6 hr). Atenolol is mainly absorbed in the stomach. The floating tablets of atenolol were prepared to increase the gastric retention, extend the drug release and to improve the bioavailability of the drug. The floating tablets were formulated using HPMC 100 cps, sodium alginate, carbopol 940 and guar gum as the polymers. The tablets were prepared by direct compression method. The formulated tablets were evaluated for the quality control tests: weight variation, hardness, friability, swelling index, floating lag time and total floating time. The in vitro release of the tablets was evaluated in 0.1N HCl (pH 1.2).The floating tablets extended the drug release up to 8 hrs. The drug-polymer interaction was evaluated by fourier transform infrared spectroscopy(FTIR).The drug release from the optimized formulation followed first order kinetics(regression coefficient,r2value =0.988) and the Higuchi equation (r2=0.996).The n value(0.260)calculated for the optimized formulation revealed that the drug release follows fickian diffusion. The similarity factor calculated for the batch F8(optimized formulation) was 70.74%, and its dissolution profile was similar to the dissolution profile of the branded extended release tablet. The FTIR studies indicated the absence of the drug-polymer interaction in the optimized formulation.