First derivative synchronous fluorescence spectroscopy for the determination of Gatifloxacin in presence of its oxidative degradation product: Application to pharmaceutical preparation.

A highly accurate and precise spectrofluorimetric method was established for quantitation of Gatifloxacin in pure material, pharmaceutical formulations and in the existence of its oxidative degradation product. The emission was recorded at 487 nm after the excitation at 290 nm. Using micelle, sodium dodecyl sulphate (SDS), enhanced fluorescence intensity of Gatifloxacin-SDS complex. The optimization of numerous experimental conditions was carried out. The improved emission showed a suitable linear correlation between derivative synchronous fluorescence power and concentration of Gatifloxacin over the range of 10 to 100 ng/mL with a determination coefficient equals 0.9996. Studying cytotoxicity and antimicrobial susceptibility for oxidative degradation product of Gatifloxacin was carried out using Gatifloxacin as a control. In comparison, the proposed method presented a superior sensitivity and enhanced stability over the reported method.

A comparative study of different aspects in manipulating ratio spectra used for the analysis of cefradine in the presence of its alkaline degradation product.

Six stability-indicating UV-spectrophotometric methods manipulating ratio spectra were utilized for the analysis of cefradine in presence of its alkaline degradate. These methods are different forms of transformations; ratio difference, mean centering, derivative ratio using numerical differentiation, derivative ratio using Savitsky-Golay filter, continuous wavelet transform and derivative continuous wavelet transform. Water was used as a solvent and the linearity ranges were 6-26 µg/mL. Determination of accuracy and precision for the suggested procedures were executed. Assessment of specificity was run through analyzing laboratory prepared mixtures containing cefradine and its alkaline degradate. The suggested methods were useful for cefradine estimation in tablets. Statistically, the outputs obtained from the recommended and published methods reveal no significant differences.

Validated spectrofluorimetric method for the determination of atorvastatin in pharmaceutical preparations.

A rapid, sensitive and simple spectrofluorimetric method was developed for the estimation of atorvastatin. In this method, the native fluorescence characteristics of atorvastatin have been studied in both acidic and basic media. High sensitivity was obtained with 5% acetic acid at 389 nm using 276 nm for excitation. Regression analysis showed a good correlation coefficient (r=0.9995) between fluorescence intensity and concentration over the range of 1.5-4 µg/mL with detection limit of 0.012 µg/mL. The proposed method was successfully applied to the analysis of atorvastatin in pure and pharmaceutical dosage forms with average recovery of 100.29±0.47%. The results were compared favorably with those of the reported method.