TY - JOUR
T1 - Enantioselective Analysis of Ritalinic Acids in Biological Samples by Using a Protein-Based Chiral Stationary Phase
AU - Zhang, Jianhua
AU - Deng, Yulin
AU - Fang, Jim
AU - McKay, Gordon
PY - 2003/11
Y1 - 2003/11
N2 - Purpose. This study was to develop and validate a new chiral HPLC-UV method for the quantitative analysis of enantiomeric ritalinic acid (RA) in human plasma. Methods. An α1-acid glycoprotein column was used with the mobile phase containing 0.4% acetic acid and 0.1% dimethyloctylamine, pH 3.4. The detection of enantiomeric RAs was at 220 nm. Results. A baseline separation for d- and l-RA was achieved by a separation factor of 2.08. Methylphenidate, the precursor of RA, was eluted with the front solvent, and thus does not interfere in the analysis of RA in our method. The assay was successfully applied for the in vitro analysis of enantiomeric ritalinic acids produced by human and dog plasma and dog liver. Conclusions. Data demonstrated that the esterase(s) in human plasma metabolize d-methylphenidate faster than its l-isomer. The yielded intrinsic clearances (Clint) are 1.02 and 2.17 μl/min/mg protein, respectively, for d and l-methylphenidate.
AB - Purpose. This study was to develop and validate a new chiral HPLC-UV method for the quantitative analysis of enantiomeric ritalinic acid (RA) in human plasma. Methods. An α1-acid glycoprotein column was used with the mobile phase containing 0.4% acetic acid and 0.1% dimethyloctylamine, pH 3.4. The detection of enantiomeric RAs was at 220 nm. Results. A baseline separation for d- and l-RA was achieved by a separation factor of 2.08. Methylphenidate, the precursor of RA, was eluted with the front solvent, and thus does not interfere in the analysis of RA in our method. The assay was successfully applied for the in vitro analysis of enantiomeric ritalinic acids produced by human and dog plasma and dog liver. Conclusions. Data demonstrated that the esterase(s) in human plasma metabolize d-methylphenidate faster than its l-isomer. The yielded intrinsic clearances (Clint) are 1.02 and 2.17 μl/min/mg protein, respectively, for d and l-methylphenidate.
KW - Chiral separation
KW - HPLC
KW - Methylphenidate
KW - Ritalinic acid
UR - http://www.scopus.com/inward/record.url?scp=0344945686&partnerID=8YFLogxK
U2 - 10.1023/B:PHAM.0000003389.77585.be
DO - 10.1023/B:PHAM.0000003389.77585.be
M3 - Article
C2 - 14661936
AN - SCOPUS:0344945686
SN - 0724-8741
VL - 20
SP - 1881
EP - 1884
JO - Pharmaceutical Research
JF - Pharmaceutical Research
IS - 11
ER -