Pharmacokinetics of nicardipine enantiomers in healthy young volunteers.
OBJECTIVE
The present study was conducted to compare pharmacokinetic behaviors of nicardipine enantiomers given in different doses with different formulations of racemic nicardipine in healthy volunteers.


METHODS
One or two 20-mg racemic nicardipine tablets, and a 40-mg sustained-release capsule of nicardipine were administered to eight healthy volunteers in a crossover fashion and pharmacokinetic parameters were evaluated. Enantiomer concentrations were determined by GC-MS combined with chiral stationary phase HPLC.


CONCLUSIONS
Serum concentration of (+)-nicardipine was approximately 2-3 times higher than that of (-)-nicardipine in 20- and 40-mg doses of conventional formulations and a non-linear increase in bioavailability with dose was demonstrated. The value for AUC of (+)-nicardipine was approximately 2.3-2.8 times greater than that of the (-)-nicardipine (P < 0.05) when 20 and 40 mg racemic nicardipine were administered in a conventional preparation. Relative bioavailability of the sustained-release preparation vs the conventional preparation was 28% and 44% for (+)- and (-)-nicardipine, respectively, for the 40-mg dose.
Inotsume
N
N
Department of Hospital Pharmacy, Tokyo Medical and Dental University School of Medicine, Japan.
Iwaoka
T
T
Honda
M
M
Nakano
M
M
Okamoto
Y
Y
Naomi
S
S
Tomita
K
K
Teramura
T
T
Higuchi
S
S
D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D006801:Humans; D008297:Male; D009529:Nicardipine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013237:Stereoisomerism
D003692:Delayed-Action Preparations; D009529:Nicardipine