High Performance Liquid Chromatographic Fluorescence 'HWHFWLRQ0HWKRGIRUWKH4XDQWL¿FDWLRQRI5LYDVWLJPLQHLQ5DW Plasma and Brain: Application to Preclinical Pharmacokinetic Studies in Rats

A highly sensitive and selective high performance liquid chromatographic fluorescence detection method has been developed and validated for the quantification of rivastigmine in rat plasma and brain. Protein precipitation and one-step liquid–liquid extraction techniques were utilized for the extraction of RSM from brain and plasma, respectively, along with an internal standard. The chromatographic separation was achieved with a column intersil ODS-3V and a mobile phase consisting of ammonium acetate buffer (20 mM, pH 4.5) and acetonitrile (76:24, v/v) delivered at a flow rate of 1 ml/min. The lower limit of quantitation for the developed method was 10 ng/ml for both matrices. The method was found to be accurate and reproducible and was successfully used to quantify levels of RSM in plasma and brain following intravenous administration of RSM in rats.