Determination of a novel photosensitizer sinoporphyrin sodium in human plasma by ultra-performance liquid chromatography–tandem mass spectrometry

•An assay for determination of a novel photosensitizer sinoporphyrin sodium in human plasma using UPLC-MS/MS was developed.•The present method was validated according to FDA and EMA guidance.•This is the first research about the validated method for the quantitation of sinoporphyrin sodium in human plasma.•The validated method was applied to the PK studies of sinoporphyrin sodium in Chinese patients with solid tumor.