Validation of a competitive chloramphenicol enzyme linked immunosorbent assay for determination of residues in Ovine tissues

Chloramphenicol is a broad-spectrum antibiotic, which has been used for treatment of animals. However, in humans it leads to hematoxic side effects particularly aplastic anaemia for which a dosage-effect relationship has not yet been established. The objective of this study was to validate a developed chloramphenicol enzyme linked immunosorbent assay for the determination of chloramphenicol residues in ovine tissues. Two groups (n=5) of sheep were injected with chloramphenicol sodium succinate at 25-mg/kg bodyweight and slaughtered one and four weeks post drug administration. Overall, the mean percentage recoveries in muscle, liver and kidney were 92 %, 70% and 78% respectively. The limits of detection were 1.2 ng/g, 0.6 ng/g and 0.8 ng/g while the detection capability was 2.5 ng/g, 1 ng/g and 1 ng/g in muscle, kidney and liver respectively. This enables the method to be used effectively as a screening tool for chloramphenicol residues in livestock products especially in the liver, muscle and kidney.Keywords: Chloramphenicol, enzyme linked immunosorbent assay, ovine, muscle, liver, kidneyEast and Central African Journal of Pharmaceutical Sciences Vol. 13 (2010) 12-1

The Pharmacokinetics of Pyrethrins in Lactating and Non-LactatingEwes After Oral and Subcutaneous Administration

Pyrethrins were administered orally and subcutaneously (SC) at 150 mg/kg body weight to 10 lactating and nonlactating ewes in a cross over experimental design. A gas chromatographic method was used for analysis of Pyrethrins in serum and milk samples from the experimentalanimals. The disposition curves were bi-exponential after first-order absorption and fitted 1 and 2 compartmental models. The maximum plasma concentration (Cmax) of Pyrethrins following oral and SC administration was 0.08 μg/ml and 0.13 μg/ml respectively withthe corresponding time to maximum concentrations (Tmax) being 1 hr and 2 hrs respectively. At 48 hours, serum Pyrethrins levels were below the limit of detection of 0.005 μg/ml. Absorption was significantly higher for SC route compared to oral routes (p0.05). The mean residence time (MRT) was 9.7 hours. Total clearance was 4,337 and 3,180 litres/kg/hr for oral and SC routes respectively. Pyrethrins were secreted in milk at levels of up to 0.005 μg/ml. It was concluded that in ewes, Pyrethrins are rapidly absorbed after orally and SC, widely distributed and eliminatedfrom the body within 24 hours. Secretion into milk occurs in ewes but the residues in milk are too low to toxic effects in humans.