Spectrophotometric quantification of dolutegravir based on redox reaction with Fe3+/1,10-phenanthroline

Background

A simple and sensitive spectrophotometric method was developed for the quantitative measurement of dolutegravir in pure form and pharmaceutical formulation. The present method was based on redox reaction between dolutegravir and ferric chloride, which upon complexation with 1,10-phenanthroline formed an orange-colored complex that showed absorption maximum at 520.0 nm.

Results

The developed method obeyed linearity in the concentration range of 40.00–140.00 μg/mL. The method was also validated as per International Council for Harmonization guidelines and the results were within acceptance values. The validated method was employed for the determination of dolutegravir in pharmaceutical dosage form and the percentage assay value was found to be 102.5, which is in agreement with its label claimed.

Conclusion

The developed redox-based colorimetric method could be used in the routine quality control analysis of dolutegravir present in various pharmaceutical dosage forms.

Quantification of Tamsulosin Hydrochloride and Solifenacin Succinate by Discriminative Derivative Synchronous Emission Spectroscopy

OBJECTIVES

The present study was undertaken with the objective to develop and validate a simple spectrofluorimetric method for the simultaneous quantification of tamsulosin hydrochloride and solifenacin succinate.

MATERIALS AND METHODS

First-derivative synchronous spectrofluorimetry was attempted for the simultaneous quantification of the analytes. Tamsulosin hydrochloride was quantified at a wavelength of 322 nm (zero-crossing wavelength point of solifenacin succinate) and solifenacin succinate was measured at 570 nm (zero-crossing wavelength point of tamsulosin hydrochloride).

RESULTS

Calibration plots were constructed over the concentration range of 2-10 µg/mL for tamsulosin hydrochloride and 30-150 µg/mL for solifenacin succinate. The method gave satisfactory results when it is validated for linearity, specificity, accuracy, precision, LOD and LOQ as per the ICH guidelines. The assay values in the commercial formulation were found to be in the percentage range of 95.0 for tamsulosin hydrochloride and 103.5 for solifenacin succinate by the proposed method. These results were well in agreement with their label claim.

CONCLUSION

The proposed synchronous analytical method can be employed for routine quality control analysis of tamsulosin hydrochloride/solifenacin succinate in tablet dose forms.