Pharmacokinetics and bioavailability studies of generic ondansetron, and the innovator preparation, in healthy Thai male volunteers.
The pharmacokinetics and bioequivalence of two oral formulations of ondansetron were evaluated; Zetron (Biolab Pharmaceutical, Bangkok, Thailand), as the test formulation and Zofran (Glaxo Wellcome Operations, Greenford, UK), as the reference formulation. The two products were administered as a single oral dose of 8 mg according to a randomized two-way crossover design to 12 healthy Thai male volunteers. The washout period between treatment was 1 week. Ondansetron plasma concentrations were measured using HPLC. The oral bioavailability of ondansetron averaged 67 per cent and the elimination half-life after oral administration was 5.6 hours. The means and parametric 90 per cent CI of the ratios of Cmax and AUC 0-alpha [mu Zetron (Test)/mu Zofran (Reference)] were 0.95 (0.84-1.07) and 0.94 (0.80-1.10), respectively. These values were well within the bioequivalence range of 0.8-1.25 as established by the US-FDA. The mean difference of Tmax (Test-Reference) was approximately 20 per cent. Thus, our study demonstrated bioequivalence of the two products (Zetron and Zofran) regarding the rate and extent of absorption.
Rojanasthien
N
N
Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Thailand.
Manorot
M
M
Kumsorn
B
B
Nawoot
S
S
Teekachunhatean
S
S
Sangdee
C
C
Apisariyakul
A
A
D000293:Adolescent; D000328:Adult; D000932:Antiemetics / Q000493:pharmacokinetics* / Q000494:pharmacology; D019540:Area Under Curve; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D016568:Drugs, Generic / Q000493:pharmacokinetics* / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D017294:Ondansetron / Q000493:pharmacokinetics* / Q000494:pharmacology; D012016:Reference Values; D012680:Sensitivity and Specificity; D013785:Thailand
D000932:Antiemetics; D016568:Drugs, Generic; D017294:Ondansetron