FORMULATION DEVELOPMENT, IN-VITRO AND IN-VIVO EVALUATION OF TAPENTADOL HCL CONTROLLED RELEASE MATRIX TABLETS USING HYDROPHOBIC POLYMERS

Abstract

Tapentadol is a centrally acting synthetic analgesic, having biological half-life of 4 hours, its systemic bioavailability is 32%, is a suitable candidate for controlled release dosage form. The main aim of the present investigation was to formulate controlled release matrix tablets by using hydrophobic polymers like carnauba wax, eudragit L-100 and hydrogenated castor oil at different concentrations by using direct compression and melt granulation techniques, for an extended period of 24 hours to relieve moderate to chronic pain. Among all the formulations T-12 was selected as optimized one based on its physical parameters and in-vitro drug release profiles. The FTIR and DSC results of optimized formulation revealed that there is no incompatibility between drug and excipients used. For optimized formulation(T-12), the drug release mechanism was explored and explained by zero-order (r²=0.987), first-order (r²=0.947), Higuchi (r²=0.967) and Korsmeyer-peppas (r²=0.982 & n=0.855) equations, which explained the drug release follows zero-order and is fit for Higuchi equation & mechanism was anomalous diffusion i.e. diffusion and erosion.  Biopharmaceutical study of the optimized (T-12) formulation in rabbit model showed 24 h prolonged drug release in-vivo. The results suggested that melt granulation technique, is a suitable method to formulate controlled release Tapentadol HCl and it can Perform therapeutically better than conventional immediate release dosage form.