Validation study of a method for assaying DE-310, a macromolecular carrier conjugate containing an anti-tumor camptothecin derivative, and the free drug in human plasma by HPLC and LC/MS/MS.
DE-310 is a macromolecular carrier conjugate containing an anti-tumor camptothecin derivative, DX-8951, conjugated to a water-soluble polymer by means of a peptide spacer. New assay methods have been developed to determine the polymer-bonded DX-8951 conjugate, free DX-8951, and Glycyl-DX-8951 in human plasma. Solid-phase extraction was used to extract free DX-8951 and Glycyl-DX-8951 from plasma, and LC/MS/MS (Method I) was used to determine the amount of each analyte. Protein precipitation was used to extract Conjugated DX-8951, which was then digested with thermolysin. HPLC (Method II) was used to determine the productive compound (Phenylalanyl-Glycyl-DX-8951). The lower limit of quantitation of DX-8951 was 50 pg/ml, of Glycyl-DX-8951 was 80 pg/ml, and of Conjugated DX-8951 was 100 ng/ml (as DX-8951 equivalent). Both methods showed satisfactory sensitivity, precision, and accuracy.
Oguma
Toshihiro
T
Drug Metabolism and Physicochemical Property Research Laboratory, Daiichi Pharmaceutical Co. Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan. ogumab0g@daiichipharm.co.jp
Cicci
Dino
D
Gaudette
Fleur
F
Gauthier-Dubois
Ginette
G
Guilbaud
Rudolf
R
Atsumi
Ryo
R
D000970:Antineoplastic Agents / Q000097:blood*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000097:blood* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods; D004355:Drug Stability; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013820:Thermolysin
D000970:Antineoplastic Agents; C452060:DE-310 cpd; C501379:glycyl-DX-8951; D013820:Thermolysin; C095887:exatecan; D002166:Camptothecin