Brenda Vermeulen

Drug administration to poultry

Drugs can be administered to birds either individually or as a flock treatment. For poultry, drinking water and feed medication are preferred, but in the case of serious disease, parenteral administration can be an alternative. For an efficient and safe therapy, data on drug pharmacodynamics and pharmacokinetics are required. Therefore, the gastrointestinal anatomy and physiology of birds, and the elimination of drugs in birds are discussed in this review. In addition, important aspects of drinking water medication, such as water quality, individual water uptake, drinking water system, lighting periods and drug formulations are discussed. Also, some requirements concerning feed medication are mentioned. Finally, parenteral and vaccine administration in the poultry industry are described.

Validation of a high-performance liquid chromatographic method for the determination of ibuprofen enantiomers in plasma of broiler chickens.

To characterise the pharmacokinetic properties of each enantiomer of ibuprofen in broiler chickens, a stereospecific HPLC method based on a alpha1-acid glycoprotein bonded chiral stationary phase has been validated. S-(+)-naproxen was used as internal standard. Enantiomers of ibuprofen and S-(+)-naproxen were baseline separated using a mobile phase consisting of 0.1 M phosphate buffer pH = 7 and 0.4% 2-propanol. The method is precise, specific, accurate and reproducible. Recoveries were higher than 80% and the limits of quantification for R-(-)- and S-(+)-ibuprofen were 1.16 and 1.37 microg ml(-1), respectively. The method seemed suitable for the pharmacokinetic studies of ibuprofen in chickens.

The formulation and stability of erythromycin-benzoyl peroxide in a topical gel.

The combination of benzoyl peroxide and erythromycin is used for the local treatment of acne and available as a commercial preparation. Because of the stability problems of erythromycin an extempore preparation is required. The influence of storage temperature and non active ingredients on the stability of benzoyl peroxide and erythromycin in topical gel preparations for extempore compounding is described. A microbiological and an HPLC method were used to determine the erythromycin and the benzoyl peroxide concentrations, respectively. For a formulation compounded with hydroxyethylcellulose no stability problems were observed. For the formulation containing Carbopol 940, the levels of erythromycin varied over a wide range due to precipitation and aggregation of the drug during compounding.

PHARMACOKINETICS AND EFFICACY OF AMOXYCILLIN IN THE TREATMENT OF AN EXPERIMENTAL STREPTOCOCCUS BOVIS INFECTION IN RACING PIGEONS (COLUMBA LIVIA)

The pharmacokinetics of amoxycillin in pigeons (Columba livia) and the efficacy of amoxycillin treatment in pigeon streptococcosis, were investigated. After intravenous administration of 150 mg.kg-1 amoxycillin, the drug plasma concentration-time profile fitted an open two-compartment model. Amoxycillin was quickly cleared from the circulation with a mean half-life of 66 min and showed a distribution volume of 0.9 L.kg-1. The absolute oral bioavailability of amoxycillin was 50.1%. A 5-day drinking water treatment with amoxycillin (1500 mg.L-1, corresponding to 112.0 mg.kg-1.day-1 during day-light hours) significantly reduced the postinoculation morbidity in pigeons experimentally infected with Streptococcus bovis, compared to untreated infected controls.

Effect of Ibuprofen on Coccidiosis in Broiler Chickens

Abstract Ibuprofen (IBU)—a nonsteroidal anti-inflammatory drug—inhibits the biosynthesis of prostaglandins with pro-inflammatory and immunosuppressive properties and is therefore proposed as a candidate molecule for the treatment of coccidiosis in broiler chickens. In all experiments, IBU was administered via drinking water. In a first experiment, chickens were infected at 10 or 21 days of age with oocysts of Eimeria acervulina (5 × 104), Eimeria maxima (3 × 104), and Eimeria tenella (7.5 × 103) and medicated with IBU at a dose of 15 mg/kg body weight (BW). In a second experiment, chickens were infected at 6 days of age with 104 oocysts of E. acervulina and medicated with IBU at a dose of 100 mg/kg BW. In the third experiment, an inoculum consisting of 5 × 104 or 105 E. acervulina oocysts was administered at 6 days of age to chickens medicated with IBU at a dose of 100 mg/kg BW. In a fourth experiment, the effect of IBU on sporulation and infectivity of E. acervulina oocysts was studied. Coccidial lesion scores (CLSs), oocyst shedding, and weight gain were used as evaluation parameters in all experiments except the fourth, where weight gain was not taken into account. In addition, the sporulation percentage was determined in the last experiment. No influence of IBU on the indicated parameters was observed after providing the drug at a dose of 15 mg/kg BW, whereas CLSs and oocyst shedding were reduced when IBU was provided at a dose of 100 mg/kg BW. However, IBU did not significantly show any effect on the degree of sporulation and infectivity of E. acervulina oocysts at a dose of 100 mg/kg BW.