Development of an UHPLC-UV Method for Quantification of Three Phenyl 4-(2-oxo-3-alkylimidazolidin-1-yl)benzenesulfonates in CD-1^® IGS Female Mouse Plasma

Phenyl 4-(2-oxo-3-alkylimidazolidin-1-yl)benzenesulfonates (PAIB-SOs) are new antimitotic prodrugs bioactivated by the enzyme CYP1A1 into phenyl 4-(2-oxo-3-imidazolidin-1-yl)benzenesulfonates (PIB-SOs) that are potently (nM) and selectively inhibiting the growth of CYP1A1-expressing breast cancer cells. The screening program identified three PAIB-SOs designated as CEU-835, CEU-934, and CEU-938 for further pharmacokinetic studies. A novel method for their quantification in CD-1^® IGS female mouse plasma using a Waters UHPLC ACQUITY Arc system was developed and validated. Their analytical measurements ranged from 7.3 to 1484 ng/mL. They exhibited linearity between 7.3 and 1484 ng/mL. They also showed good resolutions (2.21–4.99) and good theoretical plate numbers (14707–70580). Moreover, they were robust at wavelengths between 273 and 310 nm and sensitive from 2 to 62 AU/ng mL⁻¹. This new method is indispensable to assess PAIB-SOs half-life in mouse plasma and for the quantification of PAIB-SOs in other biological matrices.