The #x201C;On Line#x201D; Determination of Cefsulodin by High Performance Liquid Chromatography in CSF and Plasma of Rats

摘要

After an intraveinous injection of 20 mg.kg#x2212;1of cefsulodin in anaesthetized rats, the cerebrospinal fluid (CSF) and plasma drug levels were determined on line by HPLC. The CSF was withdrawn from the IIIe venticle at a flow rate of I #x3BC;l. minute and pushed with a peristaltic pump, via a teflon tube into a #x201C;micro vial#x201D; inside the WISP vial. At the end of fiveteen minutes, about 15 #x3BC;1 of CSF was collected and a small volume (7 #x3BC;l) was injected by the WISP into the column, the excess of CSF was discarded by another teflon tube inside the #x201C;micro-vial#x201D;. After the injection, the continous flow of CSF filled the #x201C;micro vial#x201D;, an injection was running at fiveteen minutes and so on during three hours. Plasma samples were collected every thirty minutes, and after methanol extraction cefsulodin levels were determined by HPLC. Given the low drug levels found in the CSF, this method appeared very sensitive; it was a direct, rapid, automatic technique. Other biological molecules can be determined by this automatic dosage.