Influence of closure of the reticular groove on the bioavailability and disposition kinetics of meclofenamate in sheep.

Sodium meclofenamate is a non-steroidal anti-inflammatory drug with anaphylactic protective activity in cattle. The objectives of this study were to describe the pharmacokinetic behaviour of sodium meclofenamate after intravenous and oral administration to sheep and to determine the influence of closure of the reticular groove on the bioavailability of the drug. Sodium meclofenamate was administered by the intravenous (2.2 mg/kg) and oral (20 mg/kg) routes to sheep (n = 6). During the oral study the reticular groove was closed by intravenous administration of lysine vasopressin (0.3 IU/kg) or left open (saline solution). The closure of the reticular groove was assessed by determination of the blood glucose curves after oral administration of a glucose solution. After intravenous administration of meclofenamate, the distribution and elimination half-lives of the drug were 7.2 min and 542 min respectively, Vss was 1.68 L/kg and ClB was 2.47 mliter/min kg. Two different patterns of the plasma concentration curves were observed after oral administration of sodium meclofenamate. When the reticular groove was closed, two peaks were observed (tmax-1 12-15 min, Cmax-1 3.30-24.01 micrograms/mliter; and tmax-2' 52.50-75 min, Cmax-2, 6.45-11.08 micrograms/mliter).