Pharmacokinetic studies of meloxicam after its intravenous administration in local goat (Capra hircus) of Assam

Aim: The aim of the present study was to determine the meloxicam concentrations in the plasma of goats at different time intervals after its administration by IV route and data were used to determine the different pharmacokinetic parameters and the bioavailability of meloxicam in goats. Materials and Methods: The present study was conducted on 12 to 18 months old, five adult male local goats (Capra hircus) of Assam, with body weight ranging between 10 to 18 kg. All goats were clinically sound and healthy and reared at Goat Research station, Burnihat, Assam. A single dose of meloxicam was administered intravenously into the jugular vein of goats at the rate of 1 mg/kg body weight. Blood samples were analyzed with the help of high performance liquid chromatography (HPLC) system. Results: After single intravenous administration of meloxicam at the dose rate of 1mg/kg, the mean peak plasma level of the drug was 6.538 [+ or -] 0.1189 µg/ml at 2 min. The mean elimination half life ([t.sub.1/2β]) and mean distribution half life ([t.sub.1/2α]) were 484.5 ± 85.1202 min and 28.68 ± 1.4206 min respectively. The mean values of AUC and AUMC were 2635.272 ± 94.2389 µg.[min.sup.2]/ml and 1620332 ± 92456.46 µg.[min.sup.2]/ml respectively. The mean values of volume of distribution (Vd) and mean residence time (MRT) were 0.276 ± 0.0103 L/kg and 612.948 ± 14.5771 min respectively. Conclusion: After calculating various pharmacokinetic determinants, dosage regimens were computed for meloxicam in goats, based on minimum effective therapeutic plasma concentration of 0.7 µg/ml. To maintain the minimum effective concentration of 0.7 µg/ml in plasma for 25 hours following iv administration of meloxicam, an initial loading dose of 1.1 mg/kg body weight followed by a maintenance dose of 1mg/kg body weight/day is recommended. Keywords: goat, meloxicam, pharmacokinetic parameters