Narendra M. Gowekar

  The present work describe simple, sensitive, rapid, accurate, precise and economic dual wavelength spectrophotometric method for the simultaneous estimation of Nebivolol hydrochloride and Hydrochlorothiazide in combined tablet dosage form. The principle for dual wavelength method is “the absorbance difference between two points on the mixture spectra is directly proportional to the concentration of component of interest”. The utility of this method is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The method was based on determination of Nebivolol hydrochloride at 246 nm and 292 nm and Hydrochlorothiazide at 264 nm and 295 nm. The two drugs follow Beer’s law over the concentration range of 5-30 µg/ml. The method was successfully applied to pharmaceutical dosage form. The results of analysis have been validated as per ICH guidelines.

  The present work deals with development and validation for simultaneous determination of antihistaminic drugs in pharmaceutical formulations. A rapid, precise and specific high performance liquid chromatography (RP-HPLC) method was developed for Levocetirizine dihydrochloride and Phenylephrine. Chromatographic separations was achieved on Waters Younglin system C-18 (5μm, 250×4.6 mm) HPLC column within a short runtime of 10 min. HPLC system having isocratic mode, with mobile phase containing methanol : water (pH 3) (70:30% v/v) and flow rate maintained at 1.0 mL/min was used. Effluents were monitored at 230 nm. Retention time of Levocetirizine dihydrochloride and Phenylephrine were found to be 2.6 and 4.6 min respectively. Linearity was studied in the concentration range of 2 to 12 μg/mL and 12 to 72 μg/ mL for Levocetirizine dihydrochloride and Phenylephrine respectively, with a correlation coefficient of 0.998 and 0.999 respectively. The proposed method was validated according to the ICH guidelines with respect to specificity, linearity, accuracy, precision and robustness.

  A new simple, accurate, precise, highly sensitive and reproducible difference spectrophotometric method for the determination of Fluvastatin in bulk and pharmaceutical dosage form is described. Difference spectroscopic method is based on the principle that Fluvastatin exhibit two different forms; in acidic and basic medium which differs in their absorption spectra. The difference spectra were obtained by reading the absorbance of Fluvastatin in 0.1N HCl in the reference cell and the absorbance of Fluvastatin in 0.1N NaOH in the sample cell and vice versa; in the difference spectrum maxima and minima were seen at 229nm and at 304nm respectively. The amplitude values were calculated, which was plotted against concentration. The method was found to be linear in the concentration range of 10-50 μg/ml. The percentage recovery was found to be between the ranges from 99.44 % to 100.45 %. The LOD & LOQ was found to be 0.215 μg/ml & 0.652 μg/ml respectively. The proposed method was statistically validated and successfully applied for analysis of Fluvastatin in capsule dosage forms. As per ICH guidelines the results of the analysis were validated statistically and were found to be satisfactory.