Author(s): Sachin Shivling Bhusari*, Shreya Hiralal Waghmare, Pravin Shridhar Wakte
The present research work demonstrates an analytical method development for simultaneous estimation of Rifampicin (RIF) and its bioenhancer; 3’,5- dihydroxyflavone-7-O-β-D-galacturonide-4’-O-β-D-glucopyranoside (CC-I) in combined dosage form using Q-absorbance ratio concept. While method development, two different wavelengths one representing Iso-absorptive point (370 nm) and other representing the λmax of Rifampicin (239 nm) were used. Optimum response was obtained in solvent system that comprises methanol and water in ratio of 80:20 v/v. Proposed UV method was found to be linear over the concentration range of 2-20 µg/ml for Rifampicin and that of 1-24 µg/ml for CC-I. On the basis of recovery studies after standard addition, accuracy of proposed method was found to be in between 99.94 to 100.30 and 99.90 to 99.96 % for RIF and CC-I respectively. Intra-day precision of the method in terms of % relative standard deviation was found to be in between 0.21 to 1.36 and 0.21 to 1.77 for RIF and CC-I respectively. Inter-day precision range of the method for RIF and CC-I was found to be in between 0.13 to 1.94 and 0.11 to 1.58 respectively. LOD and LOQ of proposed UV method were 0.043 and 0.014 µg/ml for RIF and 0.37 and 0.12 µg/ml for CC-I. Proposed UV method was robust and rugged in nature. Proposed method was successfully used for the estimation of RIF and CC-I contents of in-house formulation consisting of APIs and the common excipients.