DESIGN, FORMULATION AND IN VITRO EVALUATION OF SUSTAINED RELEASE PULSATILE CAPSULE OF METOPROLOL TARTRATE

Pulsatile system is gaining a lot of interest as it increases patient compliance by means of providing time and site specific drug delivery system. This work will aim at the design of a sustained release formulation with potential use of metoprolol tartrate capsule which is used in the treatment of hypertension. The design involves the preparation of cross linked hard gelatin capsules by using formaldehyde, then the drug diluents mixture loaded in, which was separated by using hydrogel plugs of different polymers, such as, HPMC 15cps, HPMC 50cps, HPMC 100cps, HPMC K4M, HPMC K15M, HPMC K100M, xanthan gum, carbomer 940, carbopol 971, sodium CMC and sodium alginate of two different amounts (75mg and 100mg respectively). Prepared formulations were subjected to evaluation of various phycal parameters and in vitro drug release studies. From the in vitro dissolution studies it was found that by increasing the amount of polymer, release rate was decreased. 75mg of HPMC 15cps showed 91.23% drug release in 5hr whereas 100mg showed 96.68% drug release in 7hr. Similar decrease in the release rates were found with the increase of other polymers of the study. Furthermore the release data was fitted to various mathematical models such as Zero order, First order, Higuchi, Korsmeyer Peppas and Hixson-Crowell kinetics. The drug release follows mixed order kinetics and mechanism was found to be non-Fickian diffusion. As this drug delivery system is still in the developmental stage much more research can be performed to make it as a practical clinical alternative