Formulation and evaluation of controlled-release tablet of zolpidem tartrate by melt granulation technique.

The present investigation describes the influence of the concentration of PEG 6000 as a melt binder and ratio of HPMC K4M : PVP on Zolpidem tartrate controlled-release tablet formulations using 3(2) full factorial design. The ratio of HPMC K4M and PVP K30 (X(1)) and the concentration of melt binder (X(2)) were selected as independent variables, and drug release at 1 hr (Q(1)), 4 hr (Q(4)), 8 hr (Q(8)), diffusion coefficient (n), and release rate constant (K) were selected as a dependent variable. Tablets were prepared by melt granulation technique and evaluated for various evaluation parameters. It was observed that concentration of melt binder had significant effect on Q(1), Q(4), n, and K Binder concentration 25% w/w was found optimum. Optimized formulation (F(7)) showed good similarity with theoretical profile of drug. The X(2) variable had a significant effect on dependent variables, and the X(1) variable had no significant effect on dependent variables.