[High performance liquid chromatographic determination of astromicin and piperacillin used in combination in blood samples].

Aminoglycoside and beta-lactam antibiotics are often used in combination, and many synergistic effects have been reported. We describe here a high performance liquid chromatographic determination method for each of astromicin (ASTM) and piperacillin (PIPC) in blood samples of several species. The procedure for ASTM included purification with CM-Sephadex, separation on a reversed phase column (C-18) and derivatization with o-phthalaldehyde (OPA). The procedure for PIPC included deproteinization with acetonitrile, centrifugation and separation on a reversed phase column (C-18). Either of the drugs did not affect the determination of the other. The detection limits were 0.1 microgram/ml for ASTM and 0.5 microgram/ml for PIPC. These sensitivities seem good enough for a clinical application of the method considering usual dosage levels of these drugs.