Surfactant/ionic liquid aqueous two-phase system extraction coupled with spectrofluorimetry for the determination of dutasteride in pharmaceutical formulation and biological samples

•SDS/IL ATPS for theseparation/analysis dutasteride.•ATPS not only extracted dutasteride but also sensitized its fluorescence intensity.•Synergistic effect of SDS and IL was investigated.•The proposed method was applied to dutasteride in real sample.

A novel separation/analysis method was developed for the determination of dutasteride in a pharmaceutical formulation and biological samples, which based on surfactant dodecyl sodium sulfate (SDS)/ionic liquid 1-hexyl-3-methylimidazolium bromide (IL, [C6min]Br) aqueous two-phase system (ATPS) extraction coupled with spectrofluorimetry. The ATPS was formed owing to new ordered molecular assembly SDS/IL, which not only extracted dutasteride but also sensitized its fluorescence intensity due to synergistic sensitizing effect. Under optimum conditions, a linear calibration curve was obtained in the range of 0.016–0.64 μg mL−1 with r = 0.9991 (n = 8). The detection limit was 2.2 ng mL−1. The preconcentration factor was 7.5. The proposed green analytical procedure was satisfactorily applied to the analysis of dutasteride in dutasteride soft gelatin capsule and human serum with the recovery of 96.7–108.0%. The obtained results of this work were in good agreement with the results of HPLC. The extraction mechanism ATPS-based was also discussed.

Graphical abstractThe fluorescence intensity of dutasteride after extraction was about 10 times than that of before extraction. The fluorescence sensitization is possibly caused by (1) concentration enrichment of dutasteride after extraction; (2) the sensitized effect of SDS/IL on fluorescence intensity.Figure optionsDownload full-size imageDownload as PowerPoint slide