ABSTRACT:
Mini-tablets are tablets with a diameter equal to or smaller than 2-3 mm. In the present work both immediate and sustained release mini-tablet of terbutaline sulphate was formulated and evaluated for different pre and post compression parameters. Immediate release tablets were formulated by adding CCS and SSG as superdisintegrant. while sustained release action is achieved by dip coating method. After evaluating all tablets the results are found to be within pharmacopoeial limits. The percentage drug content of terbutaline sulphate for both the core mini-tablets of IRMT-A to IRMT-D ranges from 95.20 to 98.56 % and SRMT 93.25 % indicating good content uniformity in both the batches. The quick disintegrating time of the core mini-tablets can be attributed to the presence of the super disintegrant CCS and SSG in optimum concentration. After dissolution study it was found that when the viscosity of the pore former (HPMC) was increased (i.e. from 5cps to 15cps) as a result a decreased release of terbutaline sulphate was observed. It has been postulated that relaxation and swelling of EC films increased as the amount of HPMC in the film increased. HPMC is believed to hydrate and subsequently produce water logged regions (pores) within the film. Some HPMC migrates into the dissolution medium thereby creating regions with higher film permeability to the drug. The formulations MTICS-6 were found to release the terbutaline sulphate in both immediate (95.09 % in an h) and sustained manner and also shown better release at the end of 24 h (98.60 %) and hence were considered as the best formulations. MTICS-6 contains IRMT-A, IRMT-D, SRMT-A, SRMT-B and SRMT-F. The In vitro release profile of this MTICS coincided with the profile expected from the combination of two IRMT and three SRMT. The MTICS undergoes four processes as follows: (a) the HPMC capsule dissolves rapidly, and has no influence on the release rate of terbutaline sulphate from the MTICS; (b) once dissolved, the HPMC capsule releases the IRMT and SRMT subunits; (c) terbutaline sulphate is released rapidly from the IRMT; and (d) terbutaline sulphate is released from the SRMT over a period of 24 h. The results revealed that all the MTICS formulations release the drug by first-order kinetics. The calculated r values for Higuchi plot and Peppas plots were nearer to one in all the cases suggesting that drug released by diffusion mechanism.