Disposition kinetics, urinary excretion and dosage regimen of meloxicam in crossbred calves after single subcutaneous injection

Abstract

The disposition kinetics, urinary excretion and dosage regimen of meloxicam were investigated in crossbred calves following its single subcutaneous administration of 0.5 mg.kg^-1. The peak plasma drug concentration was attained at 6 hr and the minimum therapeutic plasma concentration was maintained from 0.5 to 48 hr of administration. The absorption half-life, apparent volume of distribution and area under the plasma concentration-time curve were 1.45±0.1 hr,0.09±0.002 L.kg^-1 and 208.9±2.81 µg. ml-1 hr respectively. The elimination half-life and total body clearance were 24.7±0.66 hr and 2.4±0.03 ml.kg^-1. hr^-1 respectively. About 3% of the total administered drug was excreted in urine within 24 hr. On the basis of disposition kinetic parameters obtained in the present study, a satisfactory subcutaneous dosage regimen of meloxicam in cattle was calculated to be 0.55 mg.kg^-1 followed by 0.4 mg.kg^-1 at 48 hr interval.