Novel methods for the spectrophotometric determination of colchicoside

Abstract

Two novel methods are presented for the spectrophotometric determination of colchicoside (COLSID). Method A involves the reaction of COLSID with Fe(III) to form complex and method B is based on the reaction of the drug with NH₂OH.HCl, the absorbances of which are measured at 458 nm and 395 nm respectively. The calibration graphs are found to be linear over 20.00-120.00 and 20.00-100.00 µgmL^-1 for methods A and B respectively. The apparent molar absorptivity for COLSID-Fe(III) and COLSID-NH₂OH.HCl are 0.146 ×10⁴ and 1.449×10⁴Lmol^-1cm^-1 respectively. The methods are successfully applied to the assay of COLSID in pharmaceutical preparations.