Distribution of cisplatin in perilymph and cerebrospinal fluid after intravenous administration in the guinea pig.

The concentration of free cisplatin was followed in plasma, scala tympani perilymph and cerebrospinal fluid (CSF) after an intravenous injection (12.5 mg/kg) in guinea pigs. Liquid chromatography with postcolumn derivatization was used for quantitative determination of the drug. The distribution of cisplatin to CSF was fast; at 10 min after drug administration the concentration was 7 micrograms/ml and the CSF:plasma ratio was 0.37. Cisplatin seems to distribute more slowly to the perilymphatic compartment. The highest concentration measured was 4 micrograms/ml at 20 min after the injection, and the perilymph:plasma ratio was 0.40 at that time. The concentration-time curves generated for cisplatin in perilymph and CSF were similar. No accumulation in the perilymphatic compartment or CSF was observed.