A new HPLC method with fluorescence detection for the determination of memantine in human plasma.

A sensitive, selective, simple and fast HPLC method based on the formation of derivative with fluorescamine was developed for the determination of memantine (ME) in human plasma. Separation was achieved on a CN column (200 mm×4.6 mm) using acetonitrile-10 mM orthophosphoric acid containing 1 mL/L triethylamine (45:55, v/v) at a flow rate of 1 mL/min. Emission and excitation wavelengths were 480 and 380 nm, respectively. Amantadine was used as an internal standard. Calibration graphs were rectilinear over the range of 1.0-100.0 ng/mL. Limit of detection and limit of quantification were found to be 0.3 and 1.0 ng/mL, respectively. Intra-day and inter-day relative standard deviation values were found to be <2.03%. Average recovery was also found to be around 94%. Proposed method was applied for the pharmacokinetic study in a healthy volunteer after a single oral administration of 20 mg of ME.