Dacarbazine (DTIC) is a prodrug that is clinically effective in the treatment of Hodgkin's disease, melanoma and soft tissue sarcoma. To better characterize the clinical pharmacology of parent drug and reactive metabolites, a reversed-phase HPLC method with UV detection was developed for simultaneous determination of dacarbazine and the metabolites 5-(3-hydroxymethyl-3-methyl-1-triazeno)imidazole-4-carboxamide (HMMTIC) and 5-(3-methyl-1-triazeno)imidazole-4-carboxamide (MTIC). Chromatographic separation was achieved with a Zorbax SB-CN column and with a mobile phase of 80% 50 mM ammonium phosphate, pH 6.5, 20% methanol and 0.1% triethylamine. HMMTIC, MTIC and DTIC were extracted from plasma with methanol precipitation of the proteins. Recovery of DTIC and the metabolites from whole blood was greater than 92%. Rapid processing of whole blood, methanol extraction and storage at -70°C substantially increased the stability of HMMTIC and MTIC from less than 15 min to 3 days. Precision for HMMTIC, MTIC and DTIC ranged from 3.7 to 16.3% relative standard deviation. The accuracy ranged from 101 to 114% for all three analytes. The validated assay was used to determine the pharmacokinetic data for dacarbazine and its active metabolites for human patients with recurrent glioma receiving DTIC intravenously.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Chromatography B: Biomedical Sciences and Applications|
|State||Published - Apr 15 2001|
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