A Synchronous Fluorescence Spectrofluorometric Method for the Simultaneous Determination of Clonazepam and Paroxetine Hydrochloride in Combined Pharmaceutical Dose Form.

Objectives: First derivative synchronous spectrofluorimetry has been found to be superior because of its highly specific spectral discrimination and readily available solvent, it is economical, eco-friendly, and lacks an extraction procedure.

Materials And Methods: In the present study, a new simple, sensitive, and time-saving first derivative synchronous spectrofluorimetry method has been developed for simultaneous estimation of clonazepam (CLO) and paroxetine hydrochloride (PH) in pharmaceutical dose forms.

Results: CLO was determined at the emission wavelength of 512.79 nm (zero-crossing wavelength point of PH). Similarly, PH was measured at 336.00 nm (zero-crossing wavelength point of CLO). The first derivative amplitude-concentration plots were rectilinear over the range of 1-5 μg/ mL for CLO and 5-25 μg/mL for PH. The method was validated statistically as per the ICH guidelines. The limits of detection were 0.055 and 0.033 μg/mL and quantification limits were 0.169 and 0.102 μg/mL for CLO and PH, respectively. The percentage recovery in commercial formulation was found to be in the range 100.45% and 99.38% for CLO and PH, respectively, by the proposed method, and percent relative standard deviation values for precision and accuracy studies were found to be less than 2.

Conclusion: This spectrofluorimetry method has been found to have several advantages such as simple spectra, high selectivity, and low interference. By virtue of its high sensitivity, this method could be applied to the analysis of both CLO and PH in their co-formulated dose forms.