FORMULATION AND EVALUATION OF MATRIX TABLET OF VENLAFAXINE HCL BY USING DIRECTLY COMPRESSIBLE CO-PROCESSED EXCIPIENT

Objective: The sustained release of drug from the dosage form is useful especially for achieving controlled plasma level of the drug as well as improving bioavailability. The objective of the present work was to release matrix tablet of Venlafaxine HCl by using directly compressible co-processed Excipient. Methods: Co-processed excipient (Chitosan 88%: eudragit s-100) was prepared in the ratio of 1:1, 1:3, and 1:5 by the solvent evaporation method. The sustained release matrix tablets were prepared by using Co-processed excipient by direct compression and formulate formulations such as F1to F9. The tablets evaluated for various physical parameters. Direct compression method followed by optimization of the evaluation parameters was employed to get the final optimized formulation. Results: The developed Co-processed excipient was characterized for DSC, FTIR, SEM and XRD which confirm the absence of any chemical changes during co-processing. Co-processed excipient prepared in the ratio of 1:5 showed excellent flow properties. Among all formulations, Optimized formulation F9 showed the desired release profile 98.7% for a period of 24 h in phosphate buffer (pH 7.4). The release co-efficient values ‘n' (>0.5) indicated that the drug release followed non fickian anomalous mechanism based on formulation factors. Developed formulations were kept for stability study for three month as per ICH guidelines and found to be stable Conclusion: Developed co-processed excipient showed good drug release retarding property and could be alternate way to overcome the problems associated with single polymer alone. Venlafaxine HCl matrices could be developed with desirable release modulation for a once daily administration