UV Spectrophotometric Analysis and Validation of Dapsone in Semisolid Dosage Form

Objectives: A new, economical, sensitive, simple, rapid UV spectrophotometric method has been developed for the estimation of Dapsone in pure form and Semisolid Dosage form. Method: This UV method was developed using methanol: RO water (75:25) as a solvent. In the present method the wavelength selected for analysis was 260nm. UV-Visible double beam spectrophotometer (Systronic 2201) was used to carry out spectral analysis. The ICH guidelines were used to validate the method. Results: The method was validated for linearity, range, accuracy, precision, robustness, LOD and LOQ. Linearity was found in the range of 3-18µg/ml. Accuracy was performed by using recovery study. The amount of drug recovered was found to be in the range of 100.1-100.5 %. The %RSD value was found to be less than 2. Conclusion: The proposed UV spectroscopic method was found to be accurate, precise, stable, linear, specific, and simple for quantitative estimation of Dapsone in bulk and Semisolid dosage form. Hence the present UV spectroscopic method is suitable for routine assay of Dapsone in bulk and Semisolid dosage form.

Inference of dominant modes for linear stochastic processes

For dynamical systems that can be modelled as asymptotically stable linear systems forced by Gaussian noise, this paper develops methods to infer (estimate) their dominant modes from observations in real time. The modes can be real or complex. For a real mode (monotone decay), the goal is to infer its damping rate and mode shape. For a complex mode (oscillatory decay), the goal is to infer its frequency, damping rate and (complex) mode shape. Their amplitudes and correlations are encoded in a mode covariance matrix that is also to be inferred. The work is motivated and illustrated by the problem of detection of oscillations in power flow in AC electrical networks. Suggestions of some other applications are given.