放射性同位素标记药物在吸收、分布、代谢、排泄研究中的应用

近年来,放射性同位素示踪技术在药物研究中得到了广泛的应用,已成为药物代谢研究中不可缺少的研究手段。利用放射性同位素及其标记物作为示踪剂来研究药物在生物体中吸收、分布、代谢、排泄(absorption,distribution,metabolism,excretion,ADME)规律具有准确、可靠、灵敏度高、专属性强、适用范围广、操作简单等优点。本文将对近年来放射性同位素在生物体内外ADME研究中的实际应用进行概述。     

药物转运蛋白功能及应用

细胞膜转运蛋白是一些药物的吸收、分布和消除的决定因素，具有重要的药剂学意义。作为异生物质排出细胞的通道，ABC转运蛋白对大多数现在使用的药物的体内行为产生重要影响，包括治疗肿瘤、艾滋病和微生物感染用药。小肽转运蛋白具有广谱的底物特异性．能够转运大量的口服的结构类似于小肽的药物。由于新的小肽和多肽模拟物类药物的迅速增加，小肽转运蛋白因可能成为药物转运系统而倍受关注。在分子水平加深对药物转运蛋白的理解势必促进药物设计与生物药剂学的发展。     

MicroRNA对药物转运蛋白和代谢酶中的调控研究

微小RNA（miRNA）是一类内源性长18～25个核苷酸的非编码小RNA分子,在进化过程中具有高度保守性,在转录后水平调控基因的表达,从而在生物过程中发挥重要的作用。生物信息学分析表明人类全部基因的1/3都受到miRNA的调控。目前的研究表明,miRNA广泛调控机体各种生理和病理过程,可能是药物个体差异的原因,在将来可作为个体化给药分子标志物或指导新药开发。     

肝脏转运蛋白在药物肝胆转运中的作用

目的对肝脏转运蛋白在药物肝胆转运中的作用作一综述,为药物肝靶向提供依据。方法根据文献,从药物不良反应、药物的矢量转运、药物肝靶向性、药物之间相互作用4个方面阐述肝脏转运蛋白对药物肝胆排泄产生的影响。结果肝脏转运蛋白引起的药物矢量转运影响药物的肝脏摄取,药物肝靶向性影响药物的疗效,药物之间相互作用影响临床用药安全和不良反应。结论肝脏转运蛋白在药物肝胆转运中起到了重要的作用,它与药物在体内各组织分布、临床疗效均有密切的联系。     

代谢组学技术在药物安全性研究中的应用

经典的对药物等化合物的安全性评价,是通过给予一定数量的实验动物大剂量的待测化合物,观察其毒性效应特征,然后将其实验结果外推到接受小剂量相同化合物的大量人群。它是一项涉及多学科的综合性的毒理学评价过程。然而,这些评价手段还存在着许多缺点,     

自组装结构药物的跨膜转运策略

药物在机体内需通过跨膜转运才能进入细胞中,进而发挥治疗作用。药物载体作为能将药物装载作用于靶细胞/组织的工具,能够解决药物在生物体内运输过程中诸如半衰期短、稳定性差和难溶于水或脂质等问题,但也存在着药物包裹率低、易渗漏的缺点。自组装是指无序的基本结构单元自发排列成有序结构。自组装药物载体可以保护药物不受生物体内免疫系统的影响,使药物在合适的条件下以可控、高效和低副作用的方式作用于靶细胞。概述自组装结构药物跨膜转运的基本概念,总结近年来生物医学领域相关的研究进展及临床应用,为研究人员提供自组装结构药物跨膜转运新的设计策略。     

Caco—2模型在肽类药物吸收特性研究中的应用

Caco－2模型作为药物离体口服特性筛选模型,已广泛用于药物在小肠处的各种转运机制研究。该模型来源于人体结肠癌细胞,含有多种代谢酶,接近体内吸收的实际情况,可区分不同药物吸收时摄取和跨膜转运过程。本文对Caco－2模型的建立及其近年来在太类及肽类类似物吸收特性研究方面的应用作一综述。     

药物转运蛋白ABCC1在食管癌组织中的表达及其意义

目的:探讨食管癌组织中药物转运蛋白ABCC1基因表达的意义。方法:采用逆转录-多聚酶链反应(RT-PCR)技术检测了29例食管癌患者的癌组织标本及其癌旁正常食管黏膜组织中ABCC1的表达,并分析其与临床病理学特征之间的关系。结果:29例食管癌组织中ABCC1的表达水平高于癌旁正常组织(P<0.001),在中低分化食管癌和肿瘤浸润深肌层或纤维层组中,ABCC1的表达水平高于高分化和癌组织浸润浅基层以内组(P<0.05)。结论:食管癌组织中ABCC1表达增高,可能与食管癌患者耐化疗药物有关。     

放射性标记药物在我国新药研发中的应用进展

放射性标记药物代谢研究在新药研发中发挥着重要作用。它提供药物的吸收、代谢、组织分布和排泄信息,在新药的代谢物安全性评价和物质平衡研究中,具有不可替代的作用。美国FDA近期发布的关于放射性标记药物临床试验的新指导原则草案,提出了更高的标准,得到业界的广泛关注。国内近年来在新药研发中,采用14C标记药物开展临床代谢试验,克服了关键技术瓶颈,积累了经验。本文综述上述研究进展,分析存在的问题,并初步展望未来的技术发展和应用。     

药物基因组学在药物研发中的转化与应用

药物安全性和有效性是新药开发和临床用药的核心问题,也是药物基因组学研究的主要内容。目前,已阐明影响药物安全性有效性及个体化差异的首要因素是药物相关生物标记。近年来,药物基因组学各机构正式成立,各发达国家也纷纷出台各种规章,对药物研发中药物基因组学的应用进行规定。药物基因组学在上市药物的评价中已获得巨大的成功,并成功指导了数例肿瘤靶向药物从研发到上市的全过程,缩短了药物开发周期、降低了研究成本及毒副反应。     

分子影像技术在药物研发中的应用

分子影像可在活体状态下对生物和生化过程进行无创研究。该技术包括分子探针和分子成像技术,可通过特异性探针或报告基因成像。运用分子影像技术可筛选侯选化合物,评价药物对肿瘤代谢、增殖、血管发生和凋亡的影响,评价药物对组织缺氧的影响。分子影像技术是药物作用机制研究的重要手段,将大大加快药物研发进程。     

Current trends in in silico,in vitro toxicology,and safety biomarkers in early drug development

The development of new medicines is a long and expensive process. Despite growing efforts in R&D over the last decades, attrition rate due to safety issues (especially cardiac and hepatic toxicity) remains a major challenge for the pharmaceutical industry. This may lead to market withdrawal or late stage halting of a drug development program. Consequently, early detection of toxicity issues is critical to avoid late-stage failures. To this end, development of predictive toxicology assays and models have become a strategic matter for drug makers. An integrated approach confronting knowledge-based data sources with in vitro and in vivo experimental data should be performed. A well-defined balance between in vivo and in vitro assays should guide the safety assessment process and include a rationale taking into account ethical considerations as well as associated resourcing involved with animal use. Innovation in de-risking strategies may support refinement of regulatory testing and contribute to (i) improve drug safety evaluation alleviating assessment of the risk-benefit ratio and (ii) promote the access to safe drugs for patients. In this review, promising innovative approaches aiming at facilitating early detection of toxicity during drug development are described.     

转运体在药物排泄中的作用及在新药研发中的意义

本文介绍了药物转运体在药物排泄过程中的作用,探讨了其在新药研发和临床应用中的可能性。通过对药物转运体功能的了解和利用,可以开发出对某些器官有靶向性的药物,或避免药物分布到某些器官中,从而提高药物的疗效,降低其毒副作用;也可以通过对转运体介导的药物相互作用及肝肠循环的研究,指导临床更加安全有效的用药。在药物研发的初始阶段,就开始重视其药动学特性,这一观念近年来已被很多人所接受。对药物转运体的深入认识和利用,建立高通量的药物转运体筛选体系,对于加速新药研发的进程将具有极其重要的意义。     

The use of pharmacokinetic and pharmacodynamic data in the assessment of drug safety in early drug development

The pharmaceutical industry continues to look for ways to reduce drug candidate attrition throughout the drug discovery and development process. A significant cause of attrition is due to safety issues arising either as a result of animal toxicity testing or in the clinical programme itself. A factor in the assessment of safety during early drug development is the pharmacokinetic profile of the compound. This allows safety data to be considered in the light of systemic drug exposure and therefore permits a quantitative assessment. This is particularly applicable when assessing the risk of a new chemical entity (NCE) in relation to safety parameters such as QT interval prolongation, where free plasma concentrations have been shown to be predictive of this property in relation to potency in preclinical testing. Prior to actual human exposure it is therefore important to be able to predict reliably the pharmacokinetic behaviour of an NCE in order to place such safety findings into a quantitative risk context. The emerging science of pharmacogenetics is likely to further our ability to assess the risk of NCEs to populations and individuals due to genetic variance. The drug metabolizing enzyme CYP2D6 has been recognized as providing the potential to result in widely differing systemic drug exposure in the patient population due to polymorphic expression. Further knowledge is likely to add to our understanding of population differences in exposure and response and aid in the identification of risk factors. One potential strategy for improving the effectiveness of the drug discovery process is to obtain clinical pharmacokinetic data more rapidly in order to assess more accurately the potential for both efficacy and safety of an NCE. Whilst procedures and technologies are available that allow this on the microdose scale, it is important that we recognize potential limitations of these approaches in order that they can be applied beneficially.     

高原缺氧对药物转运体影响的研究进展

高原具有的低氧、低气压等环境特点,会使机体产生一系列生理性变化,并影响药物的体内代谢过程。影响这个过程的因素有很多,包括胃排空、血液流变学、心肺功能、肝肾功能、药物代谢酶和药物转运体。其中,药物转运体是介导大部分药物透过细胞膜进入体内发挥药效的关键因素,研究缺氧对药物转运体的影响,对于明确药物的体内代谢过程具有重要的意义。因此,该文将从药物转运体的分类、介导的药物底物、缺氧对药物转运体表达的影响及缺氧条件下药物转运体的调控机制等方面进行综述,为深入研究高原缺氧对药物转运体的影响和药物代谢动力学参数变化提供理论依据。     

新药开发中的基因导向型个体化发展战略

药物基因组学在新药开发的多个阶段可发挥重要作用。研究者可借助基因组信息更好地发现新药的作用靶点及其作用机制,药物基因组及其相关技术的发展帮助研究者在新药开发的临床前研究阶段淘汰化学性质不良的化合物,还可指导新药开发的临床试验设计以增加药物有效性和安全性,同时降低开发所需的时间和成本。     

Inter-ethnic differences in drug response: Implications for drug development and complying with drug regulation

Abstract

The two key components of the pharmacology of a drug—dose–concentration (pharmacokinetic) and/or concentration–response (pharmacodynamic) relationships—are often influenced by genetic variations. These account for a substantial fraction of variability in dose–response or drug response, not only between individuals, but also between different ethnic groups. The approval of ‘BiDil’ for the treatment of cardiac failure in self-identified black patients is a spectacular example of inter-ethnic differences in drug response and regulatory awareness of ethnicity of the study population. Drug development programs are increasingly undertaken globally to reduce costs, shorten timeframes, and address issues concerning global prescribing. Regulatory authorities have responded to this globalization of drug development by promulgating guidelines that recommend sponsors of new drugs to explore the role of genetic variations, and potential differences in drug response, between different ethnic populations. They may refuse to accept an application, or require bridging studies, when such differences are anticipated but not adequately addressed. These bridging studies may include (i) pharmacokinetic studies, (ii) pharmacodynamic studies, (iii) dose–response studies, and/or (iv) in extreme cases, pivotal phase III studies in order to extrapolate efficacy and/or safety data from one population to another.     

提高药物临床试验安全性评价机构管理的建议

药物安全性问题是重要的公共健康问题,贯穿于新药研发的整个生命周期,在药物上市前及时发现潜在的不安全因素,充分评价药物安全性将有助于药品监管机构权衡获益与风险并尽早作出批准决定。因此,不断加强药物安全性监测工作,持续警戒药品风险信号,把握药品安全生命线,维护人民群众权益,是新药临床试验中的关注重点。梳理药物临床试验安全性评价工作中存在的问题并提出改进建议,以期为药物临床试验各方提供参考。     

Synthesis of C‐14 radiolabeled glucagon receptor antagonist and its use in a human mass balance study

The synthesis of the radiolabeled glucagon receptor antagonist 1‐[ ¹⁴ C ] was accomplished based on decarboxylative iodination of acid 2 followed by “reattachment” of ¹⁴C carboxylic function. The method allowed a significant reduction in the number of steps in preparation of the radiolabeled compound. Iodide 4 , obtained by the halodecarboxylation, was converted to cyanide 5‐[ ¹⁴ C ] , which was hydrolyzed to provide the radiolabeled acid 2‐[ ¹⁴ C ] . Coupling with β‐alanine fragment and hydrolysis of ester 6‐[ ¹⁴ C ] completed the synthesis of the target molecule 1‐[ ¹⁴ C ] . The resulting compound was utilized in a mass balance and metabolism study where hepatic oxidation followed by a trace amount of sulfate conjugation and elimination was the main clearance pathway for 1 in humans.     

药品中亚硝胺类杂质监管与检验技术研究进展

遗传毒性物质亚硝胺类杂质是近年来化学药品质量控制重点关注和检验指标之一。对比分析中国、欧盟、美国等药品监管机构对亚硝胺杂质的监管策略,分析各药品监管部门的监管机构的亚硝胺杂质检验技术研究与应用进展,提出应加强亚硝胺杂质来源的监管科学研究、完善基于风险评估的监管策略、强化监管机构间监管策略和标准的协调、加快检验技术开发和利用好抽样检验监管手段保障药品供应链安全,为做好我国化学药品质量控制提供参考。