An In Vitro Human Small Intestine Tissue Model for Drug Permeation Studies

描述(申请人提供)：口腔周围给药途径仍然是最方便的临床治疗方法，受到患者的青睐，然而，良好的生物利用度是新的候选疗法的必要特征。决定口服生物利用度的一个关键参数是药物在小肠的转运和渗透性。 上皮组织。因此，能够准确预测候选药物体内人体转运/通透性的SI上皮体外模型对制药行业具有重要意义。目前已有的体外模型存在着严重的缺陷，限制了它们在药物开发应用中的应用，包括与体内人类载体介导的转运和PAR细胞渗透的相关性较差，以及体内人类小肠代谢酶活性的缺乏。目前的建议旨在开发一种用于药物开发应用的体外人类SI。SI模型将由原代人类SI上皮细胞和培养在微孔膜支架上的成纤维细胞组成，以产生分化良好的SI组织，具有体内类似人类的药物转运和渗透特性。由于该模型是从原代正常(非癌症)SI细胞产生的，与目前基于动物或癌症来源的细胞系的现有模型相比，该组织有望提供更好的性能。重要的初步结果表明，这一目标是很容易实现的。该项目的目标包括优化培养参数、药物转运体和代谢酶的特性，以及使用一些以前使用行业标准模型Caco-2细胞进行研究的底物进行渗透研究。药物通过被动扩散和主动转运的渗透，以及转运体抑制剂的作用，将被研究。我们将对SI模型与人类以及Caco-2细胞与人类的渗透/吸收进行比较，以确定SI模型是否提供了比Caco-2模型更好的药代动力学预测。第二阶段的工作将包括将SI组织模型进一步优化为96孔的高通量筛选格式，将体外方法转移到其他实验室，以及在多个实验室进行盲法验证研究。结果将提交给美国机构间替代方法验证协调委员会(ICCVAM)进行审查和验证。此外，还将研究不同的供体和不同的病理条件对SI渗透的影响。一种准确、经济、可重复性的体外评价SI药物吸收的方法将加强药物选择过程，提高新药候选药物临床成功的概率。这种新颖的体外工具将在整个制药业获得显著的商业认可。

DESCRIPTION (provided by applicant): The perioral route for drug administration remains the most convenient way of clinical therapy and is preferred by patients, however, good bioavailability is a necessary characteristic of new candidate therapeutics. A key parameter for determining oral bioavailability is drug transport and permeability across the small intestine (SI) epithelium. Therefore, in vitro models of SI epithelium that accurately predict in vivo human transport/permeability of candidate drugs are of high interest to the pharmaceutical industry. Currently available in vitro models have significant deficiencies which limit their utility for dru development applications, including poor correlation to in vivo human carrier-mediated transport and par cellular permeation, as well as a lack of in vivo human small intestine metabolic enzyme activity. The current proposal aims to develop an in vitro human SI for use in pharmaceutical development applications. The SI model will consist of primary human SI epithelial cells and fibroblasts cultured on micro porous membrane supports to produce well-differentiated SI tissues with in vivo-like human drug transport and permeability characteristics. Because the model is produced from primary normal (non-cancerous) SI cells, the tissue is expected to provide superior performance compared to currently available models based on animal or cancer-derived cell lines. Significant preliminary results indicate that this goal is readily attainable. Aims of the project include optimization of culture parameters, characterization of drug transporters and metabolizing enzymes, and permeation studies using a number of substrates that have been previously studied using the industry standard model, Caco-2 cells. Drug permeation via passive diffusion and active transport, along with the effect of transporter inhibitors, will be studied. A comparison between the permeation/absorption in: a) the SI model vs. human and b) Caco-2 cells vs. human will be made to determine if the SI model offers improved pharmacokinetic predictions versus the Caco-2 model. Phase 2 works will include further optimization of the SI tissue model to a 96-well, high-throughput screening format, transfer of the in vitro method to other laboratories, and performance of a blinded validation study in multiple laboratories. Results will be submitted to the US Interagency Coordinating Committee on Validation of Alternative Methods (ICCVAM) for review and validation. In addition, the effect of alternative donors and various pathological conditions on SI permeation will be investigated. The availability of an accurate, cost-effective, and reproducible in vitro means of assessing SI drug absorption will enhance the drug selection process and improve the probability of clinical success of new drug candidates. This novel, in vitro tool will find signifiant commercial acceptance throughout the pharmaceutical industry.