Ketoprofen (KTP) and meloxicam (MLX) are non-steroidal anti-inflamatory drugs used extensively in veterinary medicine. The pharmacokinetics of these drugs were studied in eight dogs following a single oral dose of 1 mg/kg of KTP as a racemate or 0.2 mg/kg of MLX. The concentrations of the drugs in plasma were determined by high-performance liquid chromatography (HPLC). There were differences between the disposition curves of the KTP enantiomers, confirming that the pharmacokinetics of KTP is enantioselective. (
S)-(+)-KTP was the predominant enantiomer; the
S:
R ratio in the plasma increased from 2.58±0.38 at 15 min to 5.72±2.35 at 1 h. The area under the concentration–time curve (AUC) of (
S)-(+)-KTP was approximately 6 times greater than that of (
R)-(–)-KTP. The mean (±SD) pharmacokinetic parameters for (
S)-(+)-KTP were characterized as
T
max = 0.76±0.19 h,
C
max = 2.02±0.41
t\frac12\textel t_{\frac{1}{2}{\text{el}}}
= 1.65±0.48 h, AUC = 6.06±1.16
t\frac12l(\textz) t_{\frac{1}{2}\lambda ({\text{z)}}}
= 12.13±2.15 h, AUC
inf = 15.41±1.24

g.h/ml,
V
d/F = 0.23±0.03 L/kg, and Cl/F = 10±1.4 ml/(kg.h). Our results indicate significant pharmacokinetic differences between MLX and KTP after therapeutic doses.
dogs - ketoprofen - meloxicam - NSAID - pharmacokinetics