High-performance liquid chromatography with peroxyoxalate chemiluminescence determination of propentofylline concentrations in rat brain microdialysate.

A high-performance liquid chromatographic determination of a neuronal cell protective compound, propentofylline [3-methyl-1-(5-oxohexyl)-7-propyl-7H-purine-2(3H),6(1H)-dione] was performed combining a microdialysis technique with peroxyoxalate chemiluminescence (PO-CL) detection. The microdialysate was subjected to a fluorescent derivatization of propentofylline with 4-(N,N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole (DBD-H) without further cleanup, because the membrane used in the microdialysis excluded high-molecular-mass proteins. The proposed method showed a good linearity in the determination range of 0.031 to 1.25 ng/injection; y (microV)=4234 x (ng)- 13.43, r=0.9993 (y=peak height and x=amount of propentofylline). The very low determination limit of 0.031 ng/injection was ca. 200 times more sensitive than that of HPLC-UV determination. The HPLC-PO-CL method was applied for the first time to determine propentofylline concentration in the dialysate obtained from the rat hippocampus after a single oral administration (25 mg/kg). Propentofylline showed its maximum extracellular fluid (ECF) concentration of 125.1+/-15.1 ng/ml (mean+/-SD, n=3) at 0.33 h after administration.