High-performance liquid chromatographic method for determination of reversible isomers of SU5416

SU5416 shows light-induced reversible geometric isomerism. A simple, reliable, isocratic HPLC method using an UV–vis detector at λ425 nm was developed. The method provides efficient (RS = 3.5) analysis of the two isomers with retention of the isomeric integrity. Additionally, the method has linearity over a wide range (50–1000 μg/mL, r2 = 0.99), is accurate (99–102%, RSD <4%), and reproducible (RSD <0.8%). The method was used for analyzing pharmaceutical samples and understanding the kinetics of SU5416 isomers in methanol. In addition, this method can be used for quantifying the non-isolatable E-isomer.