Veterinary Research Communications

, Volume 30, Issue 7, pp 791–805

Plasma Disposition and Faecal Excretion of Netobimin Metabolites and Enantiospecific Disposition of Albendazole Sulphoxide Produced in Ewes


DOI: 10.1007/s11259-006-3336-y

Cite this article as:
Gokbulut, C., Cirak, V.Y. & Senlik, B. Vet Res Commun (2006) 30: 791. doi:10.1007/s11259-006-3336-y


Netobimin (NTB) was administered orally to ewes at 20 mg/kg bodyweight. Blood and faecal samples were collected from 1 to 120 h post-treatment and analysed by high-performance liquid chromatography (HPLC). Using a chiral phase-based HPLC, plasma disposition of albendazole sulphoxide (ABZSO) enantiomers produced was also determined. Neither NTB nor albendazole (ABZ) was present and only ABZSO and albendazole sulphone (ABZSO2) metabolites were detected in the plasma samples. Maximum plasma concentrations (C<max) of ABZSO (4.1 ± 0.7 μg/ml) and ABZSO2 (1.1 ± 0.4 μg/ml) were detected at (tmax) 14.7 and 23.8 h, respectively following oral administration of netobimin. The area under the curve (AUC) of ABZSO (103.8 ± 22.8 (μg h)/ml) was significantly higher than that ABZSO2(26.3± 10.1 (μg h)/ml) (p<0.01). (−)−ABZSO and (+)-ABZSO enantiomers were never in racemate proportions in plasma. The AUC of (+)-ABZSO (87.8±20.3 (μg h)/ml) was almost 6 times larger than that of (−)−ABZSO (15.5 ±5.1 (μg h)/ml) (p < 0.001). Netobimin was not detected, and ABZ was predominant and its AUC was significantly higher than that of ABZSO and ABZSO2, following NTB administration in faecal samples (p > 0.01). Unlike in the plasma samples, the proportions of the enantiomers of ABZSO were close to racemic and the ratio of the faecal AUC of (−)−ABZSO (172.22 ±57.6 (μg h)/g) and (+)-ABZSO (187.19 ±63.4 (μg h)/g) was 0.92. It is concluded that NTB is completely converted to ABZ by the gastrointestinal flora and absorbed ABZ is completely metabolized to its sulphoxide and sulphone metabolites by first-pass effects. The specific behaviour of the two enantiomers probably reflects different enantioselectivity of the enzymatic systems of the liver that are responsible for sulphoxidation and sulphonation of ABZ.


albendazolealbendazole sulphoxideenantiomersewesnetobiminpharmacokinetics





albendazole sulphoxide


albendazole sulphone


area under the plasma concentration–time curve


area under the first moment curve


dimethyl sulphoxide




flavin-containing monooxygenase


high-performance liquid chromatography


mean residence time



Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine and Research and Development LaboratoryUniversity of Adnan Menderes
  2. 2.Department of Parasitology, Faculty of Veterinary MedicineUniversity of UludagBursaTurkey