ABSTRACT
Simple, selective and sensitive stability indicating spectrophotometric methods have been developed and validated for Tiemonium methylsulphate (TIM) determination in pharmaceutical dosage form. Method A, isoabsorptive point comprised of measurement the total content of the mixture of TIM and its acid degradation product at 250 nm, while the content of acid degradation product was determined by measuring the peak amplitude of the 2D at 295.6nm, then TIM concentration can be determined by subtraction. Method B, the first derivative of ratio spectra was applied by measuring amplitudes of TIM at 224.4 nm and 247.2 nm using 20μg/mL of acid degradation product as a divisor. Method C is the ratio subtraction method. While method D is based on the measurement of first derivative amplitudes of TIM at the zero crossing point of its oxidative degradation product at 250 nm. The percentages mean accuracy for TIM was 100.39±0.33 for method A, 100.59±0.57 and 100.40±0.56 for B, 100.47±0.54% for C and 100.24±0.58% for D methods. The developed methods were validated as per International Conference of Harmonization guidelines. Furthermore, elucidation of the degradation pathway is described based on the use of the infrared spectroscopy and HPLC/MS techniques.
ABSTRACT
The present manuscript describe simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of Rifampicin and Piperine in combined capsule dosage form. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Rifampicin and Piperine show an isoabsorptive point at 387 nm in methanol. The second wavelength used is 337 nm, which is the λ-max of Piperine in methanol. The linearity was obtained in the concentration range of 5-40 μg/ml for Rifampicin and 2-20 μg/ml for Piperine. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of Rifampicin. The method was successfully applied to pharmaceutical dosage form because no interference from the capsule excipients was found. The results of analysis have been validated statistically and by recovery studies.
ABSTRACT
Three simple and sensitive methods were developed for the determination of a mixture of Rabeprazole sodium RB and Domperidone DP without prior separation. The first method A, isoabsorptive point comprised of measurement the total content of the mixture at their isoabsorptive point, while the content of RB was determined by measuring the first order derivative of its spectra at 231 nm, and the content of DP could be calculated by subtraction. The second method, B was based on the mean centering of ratio spectra, the concentration of RB was determined by measuring the amplitude at 256.4 nm and the concentration of DP was determined by measuring the amplitude at 311.8 nm. The third method C, dual wavelength method, the wavelengths selected for determination of Rabeprazole were 270 nm & 301 nm, whereas, the wavelengths selected for determination of Domperidone were 260 and 297.2 nm. The percentages mean accuracy for RB were 99.74 ± 0.498 % for method (A), 100.52 ± 0.478 % for (B) and 100.43 ± 0.502 % for (C) respectively. And that of DP were 100.28 ± 0.488 % for method (A), 99.24 ± 0.551 % for (B) and 99.95 ± 0.516 % for (C) respectively. The obtained results were statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision.
ABSTRACT
The present manuscript describe simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of cefpodoxime proxetil and ofloxacin in combined tablet dosage form. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Cefpodoxime proxetil and ofloxacin show an isoabsorptive point at 273.2 nm in methanol. The second wavelength used is 297 nm, which is the λ-max of ofloxacin in methanol. The linearity was obtained in the concentration range of 2-14 μg/ml for both cefpodoxime proxetil and ofloxacin. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of ofloxacin. The method was successfully applied to pharmaceutical dosage form because no interference from the tablet excipients was found. The results of analysis have been validated statistically and by recovery studies.