Uv Spectrophotometric Methods for Determination of Sofosbuvir in Pure Form and Pharmaceutical Dosage Forms in Presence of Its Alkaline Degradate

Aims: Two spectrophotometric methods were developed and validated for the determination of sofosbuvir in presence of its alkaline degradate.

Study Design: Ratio difference and ratio derivative methods were assisted for determination of sofosbuvir in presence of its alkaline degradate, laboratory-prepared mixtures and in tablet dosage forms.

Place and Duration of Study: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy (Girls), Al - Azhar University, between December 2019 and January 2020.

Methodology: Two analytical methods were achieved and validated for the quantitative determination of Sofosbuvir in presence of its alkaline degradate. The first method was ratio difference (RD) method, where the UV absorption spectra of different concentrations of sofosbuvir were divided by the spectrum of a certain concentration (15 µg mL-1) as a devisor of its alkaline degradate to get the ratio difference spectra. Afterwards, the peak amplitudes difference between 253.7 and 243.5 nm were measured. The second method was the ratio derivative (1DR) method, where the first derivative of the ratio spectra (1DR) was obtained and its amplitude was measured at 247 and 268 nm. Good linearity was obtained over the concentration range of 3-15 µg mL-1 for the proposed methods. The proposed procedures were adopted for the selective determination of intact Sofosbuvir in presence of up to 80% of its degradation product. Sofosbuvir was exposed to different conditions as alkaline, acidic and oxidative degradation.

Results: The proposed methods were developed and validated with good linearity range of 3-15 µg mL-1 for both methods, and also with good accuracy and precision. And the obtained results were statistically compared to those obtained by the reported method.

Conclusion: Sofosbuvir was successfully determined by the proposed ratio difference and ratio derivative methods in bulk powder, laboratory prepared mixtures and tablet dosage form with good accuracy and precision. The methods were validated according to ICH guidelines. The results obtained were compared with those of the reported method and were found to be in good agreement.