Spectrophotometric and spectrofluorimetric methods for the determination of ropinirole content in pharmaceutical dosage forms

Two simple and rapid spectrofluorimetric and spectrophotometric methods were described for the determination of ropinirole hydrochloride content in pharmaceutical dosage forms. Both methods are based on the reaction of ropinirole hydrochloride and eosin Y in aqueous medium at p H 4.0. Quenching of the fluorescence intensity of eosin Y at 540 nm upon excitation at 350 nm was used for the determination of ropinirole hydrochloride levels after ion-pair complex formation. Also, the absorbance increase of eosin Y at 546 nm after ion-pair complex formation was used for spectrophotometric measurements. Both methods showed linear relationships between the fluorescence quenching or absorbance increase and ropinirole concentration in the range of 6–150 μg/m L and 50–500 μg/m L for spectrofluorimetric and spectrophotometric methods, respectively. As no organic solvents were used in these two methods, they could be categorized as green analytical methods. Both methods were accurate(Error<1.2%) and precise(CV<1.9%), as shown by statistical analysis results. Both methods were used for determination of ropinirole hydrochloride content in pharmaceutical dosage forms without any significant interference from associated impurities.