Vol. 3, Issue 5 (2014)

Author(s):
Kameswara Rao Sankula, Dasari Nageswara Rao

Abstract:
Drugs that have narrow absorption window in the gastrointestinal tract (GIT) will have poor absorption. For these drugs, gastro retentive drug delivery systems offer the advantage in prolonging the gastric emptying time. Atenolol is an antihypertensive drug, which has low elimination half-life: 3–4 hrs. The floating tablets of Atenolol were prepared to increase the gastric retention and to improve the bioavailability of the drug. Atenolol was chosen as a model drug because it is better absorbed in the stomach than the lower gastro intestinal tract.  The rapid gastro-intestinal transit could result in incomplete drug release from the drug delivery system above the absorption zone leading to poor bioavailability of the drug. The floating tablets were formulated using HPMC K4M and HPMC K100M as the release retardant polymers, and sodium bicarbonate as the gas generating agent to reduce the floating lag time. The tablets were prepared by direct compression. The formulated tablets were evaluated for weight variation, hardness, friability, swelling index floating lag time, total floating time and dissolution rate in 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 FTIR study indicated the lack of drug-polymer interaction.