Design, development and In-vitro characterization of floating tablets of propranolol hydrochloride

The present study was carried out to prolong the gastric residence time of propranolol hydrochloride by designing its sustained release floating tablets using natural gum (xanthan gum) as cost effective, nontoxic, easily available and suitable hydrophilic matrix system compared with semi synthetic cellulosic derivative (hydroxy propyl cellulose) with respect to in-vitro drug release rate and rate of hydration of the polymer. The tablets were prepared by direct compression method using various drug to polymer (D:P) ratios. Sodium bicarbonate was used as gas generating agent. Tablets were evaluated for various parameters like floating lag time, duration of floating, content uniformity and in-vitro drug release profile. Fourier transform infrared (FTIR) and thermal analysis differential scanning colorimetry (DSC) studies of the formulation revealed there was no chemical interaction between drug, polymer and excipients. The floating lag time of all the formulations was found to be less than 3 min. The drug release mechanism from floating tablets was evaluated on the basis of Higuchi and Peppas. The release exponent, n value of the formulations ranged from 0.40 to 0.58, indicated non- fickian transport mechanism.