Design and in vitro evaluation of gastro retentive sustained release tablets of tizanidine hydrochloride
S Mandal, G N Ratan, J S Mulla, J Thimmasetty, A Kaneriya
Gastro retentive sustained release formulation of tizanidine hydrochloride based floating technology was developed and evaluated. The developed formulation is equivalent to commercial marketed product in view of its in vitro release. The developed formulation has an additional advantage like less steps of manufacturing procedure and is therefore economical. All of which made the procedure easily amenable to mass production using conventional tablet machines. Tizanidine hydrochloride floating tablet formulations were prepared with different compositions using different grade of polymers. Finally, one optimized formula for floating tablet was selected and studied in detail. The effect of formulation variables namely different polymers and concentration of polymer were studied. Tizanidine hydrochloride release was inversely proportional to the polymer concentration. Drug release from the developed formulations was dependent on the agitation intensity and hardness of tablet. Tizanidine hydrochloride release from the developed floating formulation follows first order and diffusion is found to be the main mechanism of drug release. The manufacturing procedure was found to be reproducible and formulations were stable after one month of accelerated stability studies.
Keywords: Sustained Release, Gastro Retentive, Floating Tablet, Tizanidine Hydrochloride, Formulation, Evaluation, Physical Parameters, In vitro Release, Stability.