Pharmacokinetics and bioequivalence of 20 mg omeprazole capsule in 24 healthy Korean male volunteers.
OBJECTIVE
A randomized, two-way, crossover bioequivalence study in 24 healthy Korean male volunteers was conducted to compare bioequivalence of two brands of 20 mg omeprazole capsules, Hutex omeprazole (Hutex Pharm Co. Korea) as a test and Yuhan Losec (Yuhan Co. Ltd., Korea) as a reference drug.


METHODS
Subjects were administered single dosage of 1 capsule of 20 mg of each formulation with 240 ml of water after 10 hs overnight fasting on 2 treatment days separated by one-week washout period. After dosing, serial blood sampling was held during 9 hs. Plasma was analyzed for omeprazole by a validated HPLC method with ultraviolet detection in the range of 10 approximately 1,000 ng/ml with the lowest limit of quantification of 10 ng/ml.


RESULTS
Several pharmacokinetic (PK) parameters were determined from the plasma samples, and data from reference and test formulations in the plasma were represented such as AUC0-t (1,223.3 vs 1,284.3 ng x h/ml), [formula in text](1,311.1 vs 1,410.0 ng x h/ml), Cmax (598.7 vs 598.1 ng/ml), tmax (1.9 vs 1.9 h), t1/2 (1.3 vs 1.4 h) and Ke (0.67 vs 0.67 h-1), respectively. AUC0-t, [formula in text] and Cmax were tested for bioequivalence after log-transformation of plasma data. PK parameters with 90% confidence interval (CI) of test/reference ratio based on ANOVA analysis were 0.961 approximately 1.135 for AUC0-t, 0.968 approximately 1.144 for [formula in text] and 0.951 approximately 1.117 for Cmax.


CONCLUSIONS
PK parameters with 90% CI were within the bioequivalence range of 80 - 125% of FDA statistical limit. Therefore, both omeprazole formulations were bioequivalent during fasting state in these healthy Korean male volunteers.
Rhim
S-Y
SY
Department of Surgery, Hanyang University, Seoul, South Korea.
Park
J-H
JH
Park
Y-S
YS
Lee
M-H
MH
Hwang
K-G
KG
Kim
Y-S
YS
Shaw
L M
LM
Lee
Y-S
YS
Kang
J-S
JS
D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics; D044466:Asian People / Q000235:genetics; D001682:Biological Availability; D002214:Capsules / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D018592:Cross-Over Studies; D065731:Cytochrome P-450 CYP2C19; D005215:Fasting; D005838:Genotype; D006207:Half-Life; D006801:Humans; D008297:Male; D015394:Molecular Structure; D009853:Omeprazole / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D010949:Plasma / Q000737:chemistry; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics*; D013810:Therapeutic Equivalency
D002214:Capsules; D054328:Proton Pump Inhibitors; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole