Pharmacokinetics and Tissue Residue of Cephalexin Following Single Dose Oral Administration in Poultry

The present experiment was conducted to investigate the pharmacokinetics and tissue residue study of cephalexin in poultry following single dose (40 mg.kg^-1 b.w.) oral administration. The concentration of cephalexin in plasma and tissues of poultry birds was analyzed by High Performance Liquid Chromatography (HPLC). The volume of distribution, clearance, area under curve (AUC), elimination half-life, T_max and C_max calculated were 5.029 L.kg^-1, 3.15 L.kg^-1h^-1, 12.728µg.mL^-1.h, 1.111h, 1.472h and 3.167µg.mL^-1 respectively following single dose oral administration. The highest tissue residue was found highest in kidney (0.355 µg.g^-1) and lowest in heart (0.023 µg.g^-1) after 24 hr. No residue were detected in lungs and fat tissue. No residues were detected after 72 hours of drug administration. Therefore, based on the study a primary dose of 11.5mg kg^-1 followed by maintenance dose of 11.5 mg.kg^-1 is recommended. A pre-slaughter withdrawal period of 3 days could be recommended after single dose oral administration of cephalexin.