亚硝胺类遗传毒性杂质的监管策略及思考

如何对药品中存在致癌风险的亚硝胺类杂质进行控制,已成为企业和监管部门关注的热点。本文对亚硝胺类杂质的常见类型、来源、致癌性作用特点进行梳理,并结合EMA、FDA、ICH及我国相关遗传毒性杂质控制指导原则,对制定符合我国国情的亚硝胺类杂质的监管限度和监管工作提出建议。尽管国外已陆续出台了一系列针对药品中亚硝胺类杂质的含量限定的指南性文件,但众多亚硝胺类杂质的毒性剂量、人体暴露量尚不明确,且药物合成工艺存在差异,我国无法完全照搬欧美等国的监管方法。当前应深入研究亚硝胺类杂质的遗传毒性和致癌性,从而制定符合我国国情的监管限度值和药品中亚硝胺杂质监管策略;此外,本文从解决实际问题的角度出发,讨论如何根据已有指导原则,确定在已知毒理学数据、毒理学数据不足和短期使用药物不同情况下亚硝胺类杂质的监管限度。本文将为药物生产和杂质评价与研究和监管领域相关人员提供借鉴。     

药物杂质的毒理学评价要求及进展

 药物原料或制剂中的杂质可能引起临床不良反应。杂质毒理学评价是药物研究的重要内容。ICH关于药物及制剂杂质方面指导原则规定了杂质的报告、鉴定和质控限度,含量超过质控限度的杂质应进行毒理学评价。但指导原则对于研发阶段的药物杂质和遗传毒性杂质的限度未作明确要求。EMEA对于遗传毒性杂质制定了专门的指导原则,引入了毒理学担忧阈值（TTC）的概念对遗传毒性杂质限度进行控制,遗传毒性杂质每日接触量应小于1.5 μg。FDA也推荐采用TTC原则控制遗传毒性和致癌性杂质。本文结合ICH,EMEA及美国FDA等指导原则,对药物杂质毒理学评价的要求及其进展进行了综述。     

药物杂质遗传毒性评价策略与监管研究

伴随大量创新及仿制药面世而来的是对遗传毒性杂质加强监管的迫切需求。一系列与国际接轨的指南性文件的出台，弥补了我国杂质监管的空白，但难点尚存。传统评价方法具有局限性，新方法与传统方法间缺乏一致性比较，药物特定合成路线实际产生的大量含警示结构杂质缺乏毒理学评价数据支持，毒性预测软件的预测效力不足等。本文就国内外杂质遗传毒性杂质监管科学现状、遗传毒性杂质控制策略、杂质遗传毒性评价方法进行论述，并提出充分结合计算机毒理学、毒性评价方法和符合我国国情的监管限度制定三个维度开展杂质监管工作。     

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。     

基因毒性杂质的毒理学评估策略

基因毒性杂质的限度确定是药物安全研究的重要内容.有潜在基因毒性的杂质根据其结构特征和毒理学数据可分为5类:已知有致突变性及致癌性的杂质、有致突变性但致癌性未知的杂质、含有与药物活性成分结构无关的警示结构但无致突变性数据的杂质、含与药物活性成分相关警示结构的杂质以及致癌风险高的特殊杂质.本文以毒理学评价的方法,分类对基因...     

药物遗传毒性研究技术指导原则的修订

制定本指导原则的目的是，在我国原指导原则的基础上，结合我国科研实践的经验和具体情况，参考国外相关指导原则和遗传毒性研究的进展，制定出既符合我国国情又符合国际注册要求的遗传毒性研究技术指导原则。本指导原则适用于中药、天然药物及化学药物的遗传毒性研究。遗传毒性研究是药物非临床安全性研究的一部分，本指导原则应与其他相关指导原则配套使用。     

化学药品中杂质的基因毒性评估策略以及相关分析方法研究进展

基因毒性杂质是受到药品监管机构和制药企业重点关注和控制的对象,由于其较一般杂质具有微量水平就存在潜在致突变性和致癌性风险的特点,需要严格控制其在药物中的含量以保证药物质量与临床应用的安全性。本文从识别警示结构、文献及数据库检索、量化构效关系软件预测、体内外遗传毒性试验、依照法规和指南要求制定合理限度等方面综述了评估杂质基因毒性的研究策略,并总结了目前为了应对其含量低,稳定性较差,结构多样等特点开发的各类前处理技术及分析方法,为基因毒性杂质的研究提供参考。     

基于计算毒理学的遗传毒性评价研究进展

计算毒理学是一种使用计算方法分析、模拟、可视化或预测化学品毒性的毒性评估方法,在时间、成本和动物福利方面具有明显优势。近年来,使用计算工具预测遗传毒性正受到监管机构更多的关注,ICH M7指南表明在药品监管中认可应用(Q)SAR模型预测药物杂质的Ames致突变性。本文讨论了经典的遗传毒性计算评估方法及其原理,总结目前常用的遗传毒性评价模型及模型的构建现状,回顾计算毒理学在药物杂质、纳米材料和化妆品成分的遗传毒性评价中的应用,旨在为评价遗传毒性的计算模型的构建和优化提供一定参考,进一步促进计算毒理学在国家遗传毒性监管中的应用。     

国外化合物结构-毒性数据库"TOPKAT"简介

在药品研发过程中,杂质的控制是保证药品安全性的一个重要方面.如何安全合理地确定杂质的限度,并将杂质控制在该限度内,是药品研发者面临的任务之一,也是药品评价者所关注的重点问题之一.由于杂质的毒性与其化学结构密切相关,所以,我国及ICH在杂质研究的指导原则中均引入了杂质的鉴定限度这一概念,要求对超过该限度的杂质均应进行定性研究,尽量确定其结构,然后再根据结构与毒性的关系,判断该杂质的毒性,从而为杂质限度的确定提供参考依据.     

天然药物成分致突变性风险预测与评价方法研究进展

天然药物成分复杂，无法逐一完成系统的致癌性风险评价及体内遗传毒性试验。鉴于计算机毒理学结合体外致突变风险评价方法在遗传毒性杂质致突变性评价方面的快速发展，也可考虑将此评价模式应用于天然药物成分的致突变性筛选与机制研究。从计算机毒理学和体外致突变性评价两方面出发，综述天然药物致突变性的研究方法，为其遗传毒性试验评价及监管提供借鉴。     

An update on the current status and prospects of nitrosation pathways and possible root causes of nitrosamine formation in various pharmaceuticals

Over the last two years, global regulatory authorities have raised safety concerns on nitrosamine contamination in several drug classes, including angiotensin II receptor antagonists, histamine-2 receptor antagonists, antimicrobial agents, and antidiabetic drugs. To avoid carcinogenic and mutagenic effects in patients relying on these medications, authorities have established specific guidelines in risk assessment scenarios and proposed control limits for nitrosamine impurities in pharmaceuticals. In this review, nitrosation pathways and possible root causes of nitrosamine formation in pharmaceuticals are discussed. The control limits of nitrosamine impurities in pharmaceuticals proposed by national regulatory authorities are presented. Additionally, a practical and science-based strategy for implementing the well-established control limits is notably reviewed in terms of an alternative approach for drug product N-nitrosamines without published AI information from animal carcinogenicity testing. Finally, a novel risk evaluation strategy for predicting and investigating the possible nitrosation of amine precursors and amine pharmaceuticals as powerful prevention of nitrosamine contamination is addressed.     

N-亚硝胺类基因毒性杂质的研究进展

自“缬沙坦事件”之后，N-亚硝胺类基因毒性杂质引起了业界的广泛关注。本文概述了药物中N-亚硝胺类基因毒性杂质和相关检测方法的研究进展，以及近20年来国内外有关药物中基因毒性杂质监管指南的完善历程。N-亚硝胺类基因毒性杂质作为一类高反应活性的基因毒性杂质，主要来源于药物合成过程中发生的副反应，以及药物在储存或者运输过程中发生的氧化或还原等反应。所有的动物实验表明，N-亚硝胺类具有很强的致癌性。在理论上，所有药物都存在N-亚硝胺类杂质或被N-亚硝胺类杂质污染的风险，由于该类化合物在药物中常以痕量形式存在，在分析检测过程中药物基质干扰大，因此建立便捷、高效的分析方法是非常有必要的。     

Nitrosamine Contamination in Pharmaceuticals: Threat,Impact, and Control

Nitrosamine-contaminated medicinal products have raised safety concerns towards the use of various drugs, not only valsartan and all tetrazole-containing angiotensin II receptor blockers, but also ranitidine, metformin, and other medicines, many of which have been recalled and prone to shortage. At any stages, from drug substance synthesis throughout each product's lifetime, these impurities may evolve if an amine reacts with a nitrosating agent coexisting under appropriate conditions. Consequently, drug regulatory authorities worldwide have established stringent guidelines on nitrosamine contamination for all drug products in the market. This review encompasses various critical elements contributing to successful control measures against current and upcoming nitrosamine issues, ranging from accumulated knowledge of their toxicity concerns and potential root causes, precise risk evaluation, as well as suitable analytical techniques with sufficient sensitivity for impurity determination. With all these tools equipped, the impact of nitrosamine contamination in pharmaceuticals should be mitigated. An evaluation aid to tackle challenges in risk identification, as well as suitable industry-friendly analytical techniques to determine nitrosamines and other mutagenic impurities, are among unmet needs that will significantly simplify the risk assessment process.     

Analytical Method Capable of Quantifying Eight Nitrosamine Impurities from Five Different Commercially Available Metformin Formulations with Glipizide,Glibenclamide, Gliclazide,Evogliptin, and Glimepiride by Ultra High Performance Liquid Chromatography Tripple Quadrupole Mass Spectrometry

Metformin and its combinations are widely used to treat type 2 diabetes. The drugs commonly used in combination with Metformin are Glipizide, Glibenclamide, Gliclazide, Evogliptin, and Glimepiride. Combination therapy is preferred over monotherapy of Metformin in most diabetics. About eighteen pharmaceutical manufacturers have lately recalled metformin formulation batches from the U.S. market due to N-nitrosodimethylamine (NDMA) impurities based on the food and drug administration (USFDA) guideline “Control of Nitrosamine in Human Drugs.” European Medicines Agency (EMA) and Health Canada have also established guidelines for nitrosamine impurities. Nitrosamines are well-known mutagenic impurities and probable human carcinogens found in pharmaceutical formulations. Thus, global regulatory agencies require pharmaceutical and formulation manufacturers to complete risk assessments for nitrosamine impurities for patient safety. Therefore, drug manufacturers must develop analytical techniques for monitoring trace nitrosamine impurities. Quantifying nitrosamine impurities in formulations requires modern equipment like LC-MS/MS and great intellect. The present study intends to give a single pre-packaged LC-MS/MS method parameters, including liquid chromatography and triple quadrupole mass spectrometer configuration. This method could quantify eight nitrosamine impurities from five different Metformin combinations (Metformin with Glipizide, Glibenclamide, Gliclazide, Evogliptin, and Glimepiride). The atmospheric pressure chemical ionisation (APCI) was used as an ionisation source, and the mass spectrometer was set to multiple reaction monitoring (MRM) mode for all eight nitrosamine impurities. A unified pre-packaged analytical setup allows analytical chemists to develop a reliable, sensitive, robust, and precise method for quantifying eight nitrosamine impurities from five different Metformin formulations of varying manufacturers. This analytical method saves time, money, and the environment using fewer pharmaceutical chemicals.     

The Impact of N-nitrosamine Impurities on Clinical Drug Development

Over the past few years, an increasing number of commercially available drugs have been reported to contain N-nitrosamine impurities above acceptable intake limits. Consequent interruption or discontinuation of the manufacturing and distribution of several marketed drugs has culminated into shortages of marketed drugs, including the antidiabetic drug metformin and the potentially life-saving drug rifampin for the treatment of tuberculosis. Alarmingly, the clinical development of new investigational products has been complicated as well by the presence of N-nitrosamine impurities in batches of marketed drug. In particular, rifampin is a key clinical index drug employed in drug-drug interaction (DDI) studies, and as a result of nitrosamine impurities regulatory bodies no longer accept the administration of rifampin in DDI studies involving healthy subjects. Drug developers are now forced to look at alternative approaches for commonly employed perpetrators, which will be discussed in this review.     

我国临床前药物致癌试验转基因动物模型研究进展

目的：综述我国临床前药物致癌试验转基因动物模型研究进展。方法：介绍致癌试验常用转基因动物模型的构建、利用转基因动物模型开展致癌试验的优势、国际认可及国际监管机构新药申报中的应用、国内外致癌试验相关指导原则、我国开展基于转基因动物致癌试验面临的困境以及转基因动物模型构建的最新进展。结果与结论：基于转基因动物模型的致癌试验具有诸多优势也是目前国际趋势,在我国建立临床前药物致癌试验转基因动物模型非常必要。     

The Landscape of Potential Small and Drug Substance Related Nitrosamines in Pharmaceuticals

This article reports the outcome of an in silico analysis of more than 12,000 small molecule drugs and drug impurities, identifying the nitrosatable structures, assessing their potential to form nitrosamines under relevant conditions and the challenges to determine compound-specific AIs based on data available or read-across approaches for these nitrosamines and their acceptance by health authorities. Our data indicate that the presence of nitrosamines in pharmaceuticals is likely more prevalent than originally expected. In total, 40.4 % of the analyzed APIs and 29.6 % of the API impurities are potential nitrosamine precursors. Most structures identified through our workflow could form complex API-related nitrosamines, so-called nitrosamine drug substance related impurities (NDSRIs), although we also found structures that could release the well-known small and potent nitrosamines NDMA, NDEA, and others. Due to common structural motifs including secondary or tertiary amine moieties, whole essential drug classes such as beta blockers and ACE inhibitors are at risk. To avoid the risk of drug shortages or even the complete loss of therapeutic options, it will be essential that the well-established ICH M7 principles remain applicable for nitrosamines and that that the industry and regulatory authorities keep an open communication not only about the science but also to make sure there is a good balance between risk and benefit to patients.     

Trends in excipient safety evaluation

Excipients are used in all drug products and in most food products. New technologies are being tested to increase the amount or rate of absorption of drugs and new and novel excipients may be included among them. New physical approaches such as nanoparticles of drug and excipients or lysosomes may offer better drug delivery especially of hard to absorb or difficult to formulate oral drugs. New excipients may improve or mask the flavor of foods, drugs, and dietary supplements. Recently, impurities in drug products have become subject to greater scrutiny and various international and national guidelines, guidances, and regulations have been proposed and accepted for use; excipient evaluation is included in these efforts. This symposium discussed new developmental concepts, guidelines/guidances and regulations involving impurities in excipients, new drug delivery systems involving excipients, and thoughts for possible improvement to these guidelines to promote faster regulatory acceptance of these substances.