Validation of a SPE HPLC-UV method for the quantification of a new ER-specific photosensitizer OR-141 in blood serum using total error concept

The aim of this work is to develop the first validated HPLC-UV method quantification in blood serum for a new endoplasmic reticulum (ER)-specific benzophenazine photosensitizer (OR-141). A fast solid phase extraction (SPE) cleaning sample procedure was achieved on C18 encapped (ec) SPE cartridges and the separation was performed on a RP-18e column (5 μM) using an isocratic elution with methanol. The method has been fully validated according to accuracy profiles based on total error and tolerance intervals. Calibration was performed in the matrix and trueness (<4.25% relative bias), repeatability (<4.75% relative standard deviation (RSD)), intermediate precision (<5.37% RSD), selectivity, response function, linearity, and dilution effect were evaluated for both OR-141 regio-isomers. Afterwards the developed method was successfully applied to perform the quantitative determination of OR-141 in mouse blood serum samples in a preliminary pharmacokinetic study.