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.
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