Automated liquid chromatographic analysis of the anti-tumorigenic drugs etoposide (VP 16-213) and teniposide (VM 26).
A method is described for the fully automated analysis of large numbers of 1--2 ml serum and plasma or urine samples containing the anti-tumorigenic drugs etoposide and teniposide and their aglycone. The blood samples are hydrolysed by a proteolytic enzyme, subtilisin A, prior to preconcentration on a small precolumn. The hydrolysis step serves both to release the strongly protein-bound drugs and to prevent clogging of the chromatographic system. On-line preconcentration is carried out with precolumns packed with PRP1, a micro-particulate divinylbenzene-styrene copolymeric sorbent. Chromatography takes place, after column switching, in a C18/methanol--water system. After a post-column clean-up step using continuous extraction with dichloroethane in an autoanalyzer system, native fluorescence of these analytes is used for detection of the drugs. Recovery of etoposide and teniposide from spiked serum and plasma samples was 100%. Calibration curves of etoposide and teniposide typically show correlation coefficients of 0.9994 over a two-to-three order linear range. The detection limit of etoposide is approx. 8 ng per sample. Repeatability was found to be excellent. Unattended overnight routine analysis is possible without any problems. This method, considering optimal sample throughput, reliability and selectivity, competes favourably with existing techniques for the analysis of etoposide and teniposide.
D001322:Autoanalysis; D002853:Chromatography, Liquid / Q000379:methods; D005047:Etoposide / Q000032:analysis* / Q000097:blood; D006801:Humans; D006868:Hydrolysis; D011034:Podophyllotoxin / Q000031:analogs & derivatives*; D013713:Teniposide / Q000032:analysis*
D005047:Etoposide; D013713:Teniposide; D011034:Podophyllotoxin