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

Combination therapy of aminoglycoside and beta-lactam antibiotics is often used clinically because of its effectiveness. This paper reports a high performance liquid chromatographic (HPLC) determination method for each of astromicin (ASTM) and cefoperazone (CPZ) 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 CPZ included deproteinization with methanol, 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 CPZ. These sensitivities seem good enough for a clinical application of the method considering usual dosage levels of the drugs.