Design, Formulation and Evaluation of Lamivudine Controlled Release Tablets

Objective: The main objective of present investigation is to formulate the controlled release tablet of Lamivudine using 3? factorial design. Lamivudine, a basic molecule and antiretroviral drug belongs to BCS Class III, having low permeability and high solubility.Methods: The controlled release tablets of lamivudine were prepared employing different concentrations of Carboplol974P and Xanthan gum in different combinations as a rate retarding agent by Direct Compression technique using 32 factorial design. The quantity/ concentration of rate retarders, Carboplol974P and Xanthan gum required to achieve the desired drug release was selected as independent variables, X1 and X2 respectively whereas, time required for 10% of drug dissolution t10%, t50%, t75%,t90% were selected as dependent variables.Results: Totally nine formulations were designed and are evaluated for hardness, friability, thickness, % drug content, in-vitro drug release. From the results it was concluded that all the formulation were found to be with in the pharmacopoeial limits and? the in-vitro dissolution profiles of all formulations were fitted in to different Kinetic models, the statistical parameters like intercept (a), slope (b) & regression coefficient (r) were calculated. Polynomial equations were developed for?t10%, t50%, t75%,t90%.Conclusions: According to SUPAC guidelines the formulation (F5) containing combination of 10% Carboplol974P and 10% Xanthan gum, is the most similar formulation (similarity factor f2=85.04 & No significant difference, t= 0.20046) to Innovator product (Lamivir). The selected formulation (F5) follows Higuchi’s kinetics, and the mechanism of drug release was found to be Case-II transport or typical Zero order release (Non-Fickian, n= 0.915).