Formulation and Evaluation of Atenolol Floating Tablets using Polymers

Gastro-retentive floating drug delivery system of atenolol, an antihypertensive drug with an oral bioavailability of only 50% and other 25% is excreted unchanged in faces because of its poor absorption from lower gastro intestinal tract. To improve the oral bioavailability and therapeutic effectiveness of atenolol, the gastro retentive floating drug delivery system was deemed useful. The direct compression technique was used to make floating tablets (F1 to F3), to reduce the floating delay, a natural polymer okra gum and ethyl cellulose was used together with gas producing sodium bicarbonate. Evaluations were done on the powder blends, angle of repose, bulk density, tapped density, Hausner’s ratio and compressibility index. Pre-compressional study indicates good micrometric properties of powder blend. Additionally, formulated floating tablets were evaluated for weight variation, hardness, diameter, drug content, buoyancy lag time and total floating time, impact of hardness, In-vitro swelling behaviour and In-vitro drug release. Post-compressional parameters were within limits. The results indicated that gas powdered floating tablets of atenolol containing 125mg of okra gum provides a better release for 12h i.e. 84.16%. The order of drug release showed F3<F2<F1 The mechanism of drug release pattern of this optimized formulation was found to be diffusion controlled zero order kinetics. FT-IR study revealed the absence of drug polymer interaction and exists a scope for further in-vivo evaluation using suitable model.