Absorption Ratio and First Derivative Method Estimation of Paracetamol and Flupirtine Maleate in Bulk and Pharmaceutical Dosage form

Abstract

Two methods for simultaneous estimation of Paracetamol and Flupirtine maleate in combined dosage form have been developed. The first method is the application of Q-analysis method (absorbance ratio), which involves the formation of Q-absorbance equation at 302 nm (isobestic point) and at 248 nm, the maximum absorbance of Paracetamol. The linearity ranges for Paracetamol and Flupirtine maleate were 2-35 μg/ml and 0.5- 70μg/ml, respectively. The second method was based on the use of first derivative spectroscopy, in which derivative amplitudes were measured at selected wavelengths (234 nm ZCP of Flupirtine maleate for Paracetamol and 334 nm ZCP of Paracetamol for Flupirtine maleate, without mutual interference. The linearity ranges for Paracetamol and Flupirtine maleate were 2-34 μg/ml and 2- 65 μg/ml, respectively. The accuracy of the methods were assessed by recovery studies and was found to be 99.93% ±0.549 and 100.05% ±0.665 for Q absorbance ratio method and 99.54% ±0.591 and 99.41% ±0.792 for first derivative method, for Paracetamol and Flupirtine maleate, respectively. These methods are simple, accurate and rapid; those require no preliminary separation and there fore can be used for routine analysis of both drugs in quality control laboratories.