Stability-indicating high-performance liquid chromatographic assay and analysis of decomposition products of 2-[4-[(7-chloro-2-quinoxalinyl)oxy]phenoxy]propanoic acid.

A stability-indicating HPLC assay has been developed for 2-[4-[(7-chloro-2-quinoxalinyl)oxy]phenoxy]propanoic acid (XK469). XK-469 is the 7-chloro analog of herbicide Quizalofop and is currently under development as an antineoplastic agent. HPLC separation of XK469 is achieved with an ODS column using isocratic elution of an aqueous MeOH mobile phase. The assay is reproducible (RSD=0.9%), linear (r2=0.999), accurate (error=1.2%) and sensitive (LDL=1.2 ng). The HPLC separates XK469 from its forced decomposition products. Identities of the decomposition products have been elucidated.