1H-NMR spectroscopic quantitative determination of clobazam

ABSTRACT

The 1H-NMR spectrum of clobazam showed a sharp singlet at 3.49 ppm assigned for the N-CH3, which was chosen for the quantitative measurements. The method involves comparing the integral of this signal to that of a sharp singlet at sigma 6.41 ppm assigned for maleic acid, used as internal standard for comparison. A standard curve was plotted the integration ratio Ic/Im and the amount of clobazam in mg. Good results were obtained on application of this method on authentic sample of clobazam. The mean percentage recovery is 100.12 +/- 1.133. Good recoveries were also obtained on application of this method on tablet form [Frisium] using standard addition technique. The mean percentage recoveries are 100.45 +/- 1.899 and 100.45 +/- 0.659. The results were compared with the reported spectrophotometric method. According to the variance ratio test [F test] and Student's t-test, there is no significant difference between the two methods, with respect to the precision and accuracy