Determination of cyclophosphamide enantiomers in plasma by LC-MS/MS: Application to pharmacokinetics in breast cancer and lupus nephritis patients.
This article describes the enantioselective analysis of cyclophosphamide (CPA) in human plasma using LC-MS/MS. CPA enantiomers were extracted from plasma using a mixture of ethyl acetate and chloroform (75:25, v/v). The enantiomers were separated on a Chiralcel(R) OD-R column, with the mobile phase consisting of a mixture of acetonitrile and water (75:25, v/v) plus 0.2% formic acid. The protonated ions and their respective product ions were monitored using two functions, 261 > 141 for CPA enantiomers and 189 > 104 for the internal standard (antipyrine). Recovery rates were higher than 95% and the quantification limit was 2.5-ng/ml plasma for both enantiomers. The coefficients of variation and the relative errors obtained for the validation of intra- and interassay precision and accuracy were less than 10%. The method was applied for the investigation of the enantioselective pharmacokinetics of CPA in a lupus nephritis patient treated with 1 g CPA infused over 2 h and in a breast cancer patient treated with 0.9 g infused over 1 h. No stereoselectivity in the pharmacokinetic parameters was observed for either patient. Clearance values of 2.63 and 2.93 l/h and of 3.36 and 3.61 l/h for (-)-(S) and (+)-(R)-CPA were obtained for the breast cancer and lupus nephritis patient, respectively.
De Miranda Silva
Carolina
C
Faculdade de Ciências Farmacêuticas de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Dumêt Fernandes
Bruno Jose
BJ
Marques Pereira
Maria Paula
MP
da Silva
Lucienir Maria
LM
Donadi
Eduardo Antônio
EA
do Carmo Silva Matthes
Angelo
A
Moreira de Andrade
Jurandyr
J
Lanchote
Vera Lucia
VL
D001774:Blood Chemical Analysis / Q000379:methods*; D001943:Breast Neoplasms / Q000097:blood* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007700:Kinetics; D008181:Lupus Nephritis / Q000097:blood* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013379:Substrate Specificity; D053719:Tandem Mass Spectrometry; D055815:Young Adult
D003520:Cyclophosphamide