PURPOSE: To evaluate the sensitivity requirement for LC-MS/MS as an analytical tool to support human microdosing study with sub-pharmacological dose, investigate proportionality of pharmacokinetics from the microdose to therapeutic human equivalent doses in rats and characterize circulating metabolites in rats administered with the microdose. MATERIALS AND METHODS: Five drugs of antipyrine, metoprolol, carbamazepine, digoxin and atenolol were administered orally to male Sprague-Dawley rats at 0.167, 1.67, 16.7, 167 and 1,670 microg/kg doses. Plasma samples were extracted using either solid phase extraction or liquid-liquid extraction, and analyzed using LC-MS/MS. RESULTS: Using 100 microl of plasma sample, the lower limit of quantitation for antipyrine (10 pg/ml), carbamazepine (1 pg/ml), metoprolol (5 pg/ml), atenolol (20 pg/ml), and digoxin (5 pg/ml) were achieved using an API 5000. Proportional pharmacokinetics were observed from 0.167 microg/kg to 1,670 microg/kg for antipyrine and carbamazepine and from 1.67 to 1,670 microg/kg for atenolol and digoxin, while metoprolol exhibited a non-proportional pharmacokinetics relationship. Several metabolites of carbamazepine were characterized in plasma from rats dosed at 1.67 mug/kg using LC-MS/MS. CONCLUSIONS: This study has shown the promise of sensitive LC-MS/MS method to support microdose pharmacokinetics and drug metabolism studies in human.
PURPOSE: To evaluate the sensitivity requirement for LC-MS/MS as an analytical tool to support human microdosing study with sub-pharmacological dose, investigate proportionality of pharmacokinetics from the microdose to therapeutic human equivalent doses in rats and characterize circulating metabolites in rats administered with the microdose. MATERIALS AND METHODS: Five drugs of antipyrine, metoprolol, carbamazepine, digoxin and atenolol were administered orally to male Sprague-Dawley rats at 0.167, 1.67, 16.7, 167 and 1,670 microg/kg doses. Plasma samples were extracted using either solid phase extraction or liquid-liquid extraction, and analyzed using LC-MS/MS. RESULTS: Using 100 microl of plasma sample, the lower limit of quantitation for antipyrine (10 pg/ml), carbamazepine (1 pg/ml), metoprolol (5 pg/ml), atenolol (20 pg/ml), and digoxin (5 pg/ml) were achieved using an API 5000. Proportional pharmacokinetics were observed from 0.167 microg/kg to 1,670 microg/kg for antipyrine and carbamazepine and from 1.67 to 1,670 microg/kg for atenolol and digoxin, while metoprolol exhibited a non-proportional pharmacokinetics relationship. Several metabolites of carbamazepine were characterized in plasma from rats dosed at 1.67 mug/kg using LC-MS/MS. CONCLUSIONS: This study has shown the promise of sensitive LC-MS/MS method to support microdose pharmacokinetics and drug metabolism studies in human.
Authors: Graham Lappin; Wilhelm Kuhnz; Roeline Jochemsen; Johannes Kneer; Ajai Chaudhary; Berend Oosterhuis; Willem Jan Drijfhout; Malcolm Rowland; R Colin Garner Journal: Clin Pharmacol Ther Date: 2006-09 Impact factor: 6.875
Authors: Ryan Takahashi; Shuguang Ma; Qin Yue; Heasook Kim-Kang; Yijun Yi; Joseph P Lyssikatos; Kelly Regal; Kevin W Hunt; Nicholas C Kallan; Michael Siu; Cornelis E C A Hop; Xingrong Liu; S Cyrus Khojasteh Journal: Eur J Drug Metab Pharmacokinet Date: 2014-04-03 Impact factor: 2.441
Authors: Anna Nilsson; Alexandra Peric; Marie Strimfors; Richard J A Goodwin; Martin A Hayes; Per E Andrén; Constanze Hilgendorf Journal: Sci Rep Date: 2017-07-25 Impact factor: 4.379