Formulation and evaluation of oral biphasic drug delivery system of Metronidazole using HPMC polymer

Abstract

In the present study, a newly innovative drug delivery system of biphasic Metronidazole (MTZ) tablet has been studied. An attempt was made to improve the patient’s adherence and the potential clinical outcomes by reducing the dosing frequency by formulating bilayer tablets containing Metrodinazole. Each bilayer tablet is composed of a sustained release (SR) layer and an immediate release (IR) layer for rapid drug release. Five different formulations of bilayer tablets were formulated using HPMC as hydrophilic polymer to retarded the drug release and the effect of Starch and MCC on the release profile were evaluated. Wet granulation method was used to prepare granules of the immediate and sustained release layers. The tablets were evaluated for their physical parameters and all valuesobtained found to be within the acceptable limits. The dissolution test has been carried out using the USP type II rotating paddle. Collected samples were analyzed using the high performance liquid chromatography. The mechanisms of Metrodinazole release from the sustained release layer were fitted into zero-order, first order, Higuchi, Hixon- Crowell model and Korsmeyer-Peppas release model. The results of the dissolution profiles showed that the drug release from the sustained release layer varied depending on the amount of HPMC and the presence of Starch or MCC. The kinetics of the release of MTZ from the different formulations showed good fitting with Higuchi model with correlation coefficients (R2) of 0.9965 - 0.9985. From values obtained for the diffusional exponent, n, Korsmeyer-Peppas equation observed that for all the formulations n value ranged from 0.4662 to 0.5370, and this demonstrates that the releasemechanism followed non-Fickian type of release ( anomalous transport).