Lanusse C E, Virkel G L, Sanchez S F, Alvarez L I, Lifschitz A L, Imperiale F, Monfrinotti A
Departamento de Fisiopatología, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro, Campus Universitario, Tandil, Argentina.
Res Vet Sci. 1998 Jul-Aug;65(1):5-10. doi: 10.1016/s0034-5288(98)90019-4.
The plasma and abomasal fluid disposition kinetics of ricobendazole (RBZ) after subcutaneous (s.c.) administration of a novel injectable formulation to calves, and the comparative plasma availability after s.c. injection of RBZ and that obtained after oral treatment with albendazole (ABZ), were characterised. Six parasite-free Holstein calves received RBZ (solution 150 mg ml(-1)) by s.c. injection at 3.75 mg kg(-1) (Experiment 1). Experiment 2 was conducted in two experimental phases; in phase I, five calves (Group A) received RBZ by s.c. injection and five animals (Group B) were orally treated with ABZ (suspension 100 mg ml(-1)), at 5 mg kg(-1). Drug treatments were reversed for each group in phase II and given at 7.5 mg kg(-1). Samples of abomasal fluid (via cannula) and jugular blood were collected over 72 hours post-treatment and analysed by HPLC. RBZ and its sulphone metabolite were detected in plasma following its s.c. administration. RBZ was rapidly absorbed, reaching the plasma Cmax at 4.5 hours post-dosing. The sulphone metabolite followed a similar kinetic pattern. Both molecules were rapidly and extensively distributed into the abomasum, being detected in abomasal fluid between 30 minutes and 36 hours post-administration. An extensive plasma/abomasum exchange process, with ionic-trapping in the abomasum, accounted for the higher AUC value (>200 per cent) obtained for RBZ in abomasum compared with plasma. The s.c. treatment with RBZ formulated as a solution resulted in a significantly greater plasma availability (measured as ABZ sulphoxide) than the oral treatment with ABZ (suspension) given at the same dose rates.
对犊牛皮下注射一种新型注射用制剂后，瑞考苯达唑（RBZ）在血浆和皱胃中的处置动力学，以及皮下注射RBZ与口服阿苯达唑（ABZ）后血浆药物可利用度的比较进行了研究。6头无寄生虫的荷斯坦犊牛皮下注射RBZ（150 mg ml(-1)溶液），剂量为3.75 mg kg(-1)（实验1）。实验2分两个阶段进行；在第一阶段，5头犊牛（A组）皮下注射RBZ，5头动物（B组）口服ABZ（100 mg ml(-1)混悬液），剂量为5 mg kg(-1)。在第二阶段，两组的药物处理方式互换，剂量为7.5 mg kg(-1)。给药后72小时内收集皱胃液（通过套管采集）和颈静脉血样本，并通过高效液相色谱法进行分析。皮下注射RBZ后，在血浆中检测到了RBZ及其砜代谢物。RBZ吸收迅速，给药后4.5小时达到血浆Cmax。砜代谢物呈现相似的动力学模式。两种分子均迅速且广泛地分布到皱胃中，给药后30分钟至36小时内在皱胃液中被检测到。血浆/皱胃间广泛的交换过程以及皱胃中的离子捕获，导致RBZ在皱胃中的AUC值（＞200%）高于血浆。以溶液形式配制的RBZ皮下给药所产生的血浆药物可利用度（以阿苯达唑亚砜衡量）显著高于相同剂量率口服ABZ（混悬液）。
