Effect of food on the bioavailability of oxybutynin from a controlled release tablet.
OBJECTIVE
The effect of food on the bioavailability of oxybutynin was assessed in a randomised cross-over study in 23 healthy volunteers. A single oral 10 mg dose of a controlled release oxybutynin tablet was administered after a high fat breakfast and to fasting subjects. The AUC, Cmax, tmax, t1/2 and MRT of oxybutynin and its active metabolite N-desethyloxybutynin were determined.


RESULTS
Breakfast did not change the AUC of oxybutynin but increased the AUC of N-desethyloxybutynin by about 20%. The Cmax of oxybutynin and N-desethyloxybutynin were two-fold higher when the drug was administered after breakfast compared to the fasting state.


CONCLUSIONS
Breakfast significantly reduced the MRT of oxybutynin and N-desethyloxybutynin.
Lukkari
E
E
Leiras Oy, Helsinki, Finland.
Castrèn-Kortekangas
P
P
Juhakoski
A
A
Löyttyniemi
E
E
Aranko
K
K
Neuvonen
P J
PJ
D000328:Adult; D019540:Area Under Curve; D001682:Biological Availability; D018680:Cholinergic Antagonists / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D005260:Female; D005502:Food; D018565:Food-Drug Interactions; D006207:Half-Life; D006801:Humans; D008297:Male; D008333:Mandelic Acids / Q000493:pharmacokinetics*
D018680:Cholinergic Antagonists; D003692:Delayed-Action Preparations; D008333:Mandelic Acids; C005419:oxybutynin