Abstract

DEVELOPMENT OF TELMISARTAN PREMIX CONTAINING AMORPHOUS TELMISARTAN BY SOLVENT CONTROLLED CO PRECIPITATION METHOD

Dharmendrasinh V. Dabhi* and Dasharath M. Patel

Abstract

This study was carried out to formulate Telmisartan Premix containing amorphous state of Telmisartan. Controlled co-precipitation technique is based on solvent-antisolvent precipitation mechanism which is developed in the late 1990s & is covered in detail by Shah et al 2012. This method requires the solubility of compound in polar solvent like N,N-dimethyl acetamide, N,N-dimethyl formamide and N-methyl pyrollidone. Different drug to polymer ratio of 1:1 to 1:3 and Solvent quantity were optimized by factorial design. HPMC AS LF was selected as a polymer based on primary polymer screening. Assay and Residual solvent was selected as dependent variable. Based on factorial outcomes and dissolution studies 1:3 drug to polymer ration was optimized with 75 ml of Solvent. From the results it can be concluded that Telmisartan Premix gives higher dissolution in pH 7.5 i.e 80% drug released within 15 min due to amorphous nature of Telmisartan. Further, 1:10 solvent to antisolvent ration was optimized. Chilled pH 4.5 acetate buffer was selected as antisolvent due to low solubility of Polymer and Telmisartan. To get residual solvent within limit, washing solvent amount optimized to remove residual solvent is 10 ml/gm. One factor at a time (OFAT) strategy is applied to optimized stirrer speed and drying time. Based on XRD and Moisture content results 200 RPM of mechanical stirrer and 12 hrs of drying time optimized. During 6 months accelerated stability studied Telmisartan amorphous state was found.

Keywords: Telmisartan Premix, Solid dispersion, Experimental design.