Biopharmaceutics Classification System (BCS) has gained broad acceptance in promoting the development of human drugs. To date, the applicability of existing human BCS criteria has not been evaluated in chickens. The objective of this study was to discuss the feasibility of BCS extrapolation between species and establish a preliminary chicken BCS by classifying seven veterinary commonly used drugs including metronidazole, amoxicillin, sulfamethoxazole, sulfadiazine, ciprofloxacin hydrochloride, doxycycline hydrochloride, and trimethoprim. Firstly, we finished the determination of physiological parameters affecting solubility in chickens, including body temperature, gastrointestinal pH, and the fluid volume in the gastrointestinal tract (GI), and the drug is considered highly soluble in chicken BCS when the highest dose strength is soluble in 20.40 ml (fed) or 6.73 ml (fasted) over the pH range of 1-8 at 41°C. Drug solubility classification was based on dose number calculation. Metronidazol and amoxicillin were classed differently under fed and fasted conditions. Secondly, we discussed the effect of ABC transporters (MDCK vs. MDCK-chAbcb1/Abcg2) and pH (5.5 vs. 7.4) on drug permeability and classification. The drug is classified as highly permeable when its permeability is equal to or greater than metoprolol tartrate. Though ABC transporters and pH significantly affected the permeability values of drugs (p < .05), the permeability classification of the drugs has not been changed except for sulfamethoxazole. This work highlights some of the significant challenges that would be encountered in order to develop a chicken BCS, this valuable information could serve as a helpful tool during chicken drugs development and to minimize the potential risks when developing formulations.

中文翻译：

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在鸡中使用生物药物分类系统的注意事项：以七种药物分类为例。

生物药物分类系统（BCS）在促进人类药物的开发方面已获得广泛认可。迄今为止，尚未在鸡中评估现有人类BCS标准的适用性。这项研究的目的是讨论在物种之间进行BCS推断的可行性，并通过对7种兽用常用药物进行分类来建立初步的鸡BCS，包括甲硝唑，阿莫西林，磺胺甲恶唑，磺胺嘧啶，盐酸环丙沙​​星，盐酸多西环素和甲氧苄啶。首先，我们确定了影响鸡溶解度的生理参数，包括体温，胃肠道pH和胃肠道（GI）的液体量，并且当最高剂量强度可溶时，该药物被认为在鸡BCS中是高度可溶的在20。在41°C下1-8的pH范围内40毫升（喂食）或6.73毫升（禁食）。药物溶解度分类基于剂量数计算。在喂食和禁食条件下，甲硝唑和阿莫西林的分类不同。其次，我们讨论了ABC转运蛋白（MDCK与MDCK-chAbcb1 / Abcg2）和pH（5.5与7.4）对药物渗透性和分类的影响。当其渗透性等于或大于酒石酸美托洛尔时，该药物被分类为高渗透性。尽管ABC转运蛋白和pH值显着影响药物的渗透率值（p <.05），但除磺胺甲恶唑外，药物的渗透率分类没有改变。这项工作强调了开发鸡BCS会遇到的一些重大挑战，