The pharmacokinetics of orally administered S-carboxymethyl-L-cysteine in the dog, calf and sheep

The aim of this study was to investigate the feasibility of employing S-carboxymethyl-L-cysteine as a treatment of chronic obstructive pulmonary disease in dogs. To this end the pharmacokinetic parameters of orally administered S-carboxymethyl-L-cysteine were determined in the dog, cow and sheep. Six healthy beagle clogs, six endogenous Greek sheep and four Holstein Fresian calves were orally dosed with 10 mg/kg body weight of S-carboxymethyl-L-cysteine. No significant differences in T-max and T-1/2 were reported between the species. However, significantly higher AUC((0-last)), 21.56 +/- 6.67 mu g h ml(-1) and AUC((0-infinity)), 21.63 +/- 6.68 mu g h ml(-1) were seen in the dogs compared to the sheep and calves. The calculated V-D was significantly higher in the sheep (10.4 +/- 2.7 L kg(-1)) and the calves (3.8 +/- 0.7 L kg(-1)) compared to the dogs (1.0 +/- 0.6 L kg(-1)). The rank order of increasing C-L was sheep (3.4 +/- 2.7 Lh(-1) kg(-1)) > calves (2.7 +/- 0.4 L h(-1) kg(-1)) > dogs (0.5 +/- 0.2 L h(-1) kg(-1)).The result for the dogs was significantly lower that the calculated C,, for the sheep and calves. All these results indicate that the oral administration of S-carboxymethyl-L-cysteine may be useful during the therapeutic management of chronic obstructive pulmonary disease in dogs. (C) 2010 Elsevier B.V. All rights reserved.