An innovative ratio difference spectrophotometric method was developed and validated for the determination of clonazepam (CLO) and paroxetine hydrochloride (PH) with interfering spectra in combined tablet dosage form without previous separation, showing significant advantages and applicability. By applying the ratio difference method, the difference between the two amplitude values is measured by subtraction the two values at the two selected wavelengths in the ratio spectra, so the noise will be completely cancelled. Determination of CLO was carried out by measuring the amplitude difference at λmax of 295.61 nm and 325.42 nm and PH was measured the by subtracting of amplitude difference at 290.64 nm and 320.97 nm. Clonazepam and paroxetine hydrochloride were determined in the concentration range of 5-30 µg/ml and 10-60 µg/ml respectively. The linear regression analysis for the calibration plots produced r2 = 0.9958 and r2 = 0.9992 for clonazepam and paroxetine hydrochloride respectively. The method was validated according to ICH guidelines and can be applied for routine quality control testing.
Loading....