Analytical control of genotoxic impurities in the pazopanib hydrochloride manufacturing process

Pharmaceutical regulatory agencies are increasingly concerned with trace-level genotoxic impurities in drug substances, requiring manufacturers to deliver innovative approaches for their analysis and control. The need to control most genotoxic impurities in the low ppm level relative to the active pharmaceutical ingredient (API), combined with the often reactive and labile nature of genotoxic impurities, poses significant analytical challenges. Therefore, sophisticated analytical methodologies are often developed to test and control genotoxic impurities in drug substances. From a quality-by-design perspective, product quality (genotoxic impurity levels in this case) should be built into the manufacturing process. This necessitates a practical analysis and control strategy derived on the premise of in-depth process understanding. General guidance on how to develop strategies for the analysis and control of genotoxic impurities is currently lacking in the pharmaceutical industry. In this work, we demonstrate practical examples for the analytical control of five genotoxic impurities in the manufacturing process of pazopanib hydrochloride, an anticancer drug currently in Phase III clinical development, which may serve as a model for the other products in development. Through detailed process understanding, we implemented an analysis and control strategy that enables the control of the five genotoxic impurities upstream in the manufacturing process at the starting materials or intermediates rather than at the final API. This allows the control limits to be set at percent levels rather than ppm levels, thereby simplifying the analytical testing and the analytical toolkits to be used in quality control laboratories.     

Profiling of levoamphetamine and related substances in dexamphetamine sulfate by capillary electrophoresis

A capillary electrophoresis method for the simultaneous determination of the enantiomeric purity of dexamphetamine as well as the analysis of 1R,2S-(−)-norephedrine and 1S,2S-(+)-norpseudoephedrine as potential impurities has been developed and validated. Heptakis-(2,3-di-O-acetyl-6-O-sulfo)-β-cyclodextrin was chosen as chiral selector upon a screening of neutral and charged cyclodextrin derivatives. Separation of the analytes was achieved in a fused-silica capillary at 20 °C using an applied voltage of 25 kV. The optimized background electrolyte consisted of a 0.1 M sodium phosphate buffer, pH 2.5, containing 10 mg/ml of the cyclodextrin. The assay was linear in the range of 0.06–5.0% of the impurities based on a concentration of 2.0 mg/ml dexamphetamine sulfate in the sample solution. Analysis of commercial dexamphetamine sulfate samples revealed the presence of 3–4% of levoamphetamine while norephedrine or norpseudoephedrine could not be detected, indicating that the compound was prepared by fractionated crystallization of racemic amphetamine. Comparison with polarimetric measurements indicated that dexamphetamine with an enantiomeric excess as low as 80% still passes the pharmacopeial test of specific rotation while an amount of 0.06% of levoamphetamine can be detected by capillary electrophoresis.     

EMS in Viracept—Initial (‘traditional’) assessment of risk to patients based on linear dose response relations

Prior to having performed in depth toxicological, genotoxicological and DMPK studies on ethyl methanesulfonate (EMS) providing solid evidence for a thresholded dose response relationship, we had prepared and shared with regulatory authorities a preliminary risk estimate based on standard linear dose–effect projections. We estimated that maximal lifetime cancer risk was in the order of 10⁻³ (for lifetime ingestion of the maximally contaminated tablets) or 10⁻⁴ for the exposure lasting for 3 months. This estimate was based on a lifetime cancer study with methyl methanesulfonate (MMS; as insufficient data were available for EMS) in rodents and default linear back extrapolation. Analogous estimates were made specifically for breast cancer based on short term tumorigenicity studies with EMS in rats, for the induction of heritable mutations based on specific locus and dominant lethal tests in mice and for the induction of birth defects based on teratogenicity studies in mice. We concluded that even under worst case assumptions of linear dose relations the chance of experiencing these adverse effects would be very small, comprising at most a minute additional burden among the background incidence of the patients.     

手性药物的质量控制研究

文中结合研发实例重点解读了《手性药物药学研究技术指导原则》中的药学研究思路与质量控制研究及稳定性研究等章节的内容,并归纳总结了在手性药物研发中的关键问题与常见问题。     

苹果酸舒尼替尼杂质的遗传毒性（Q）SAR评价及Ames试验评估

目的 对苹果酸舒尼替尼的3个已知杂质进行（定量）构效关系计算机模型［（Q）SAR］评价,并对杂质E进行细菌回复突变（Ames）试验研究。方法 根据国际人用药品注册技术协调会（ICH）M7指导原则的要求,采用基于专家知识规则的Derek和基于统计学的Sarah两类（Q）SAR评价系统,对苹果酸舒尼替尼的3个杂质——杂质v-7、杂质v-1及杂质E进行评价和分类。对于确定为遗传毒性阳性的杂质E,采用Ames试验进行验证。结果 苹果酸舒尼替尼的杂质v-7、杂质v-1预测结果为阴性,杂质E预测结果为阳性,且分类为3类。在加与不加S9的条件下,Ames试验中杂质E8～5000μg·皿^-1质量浓度回复突变菌落数均未超过溶剂对照组的2倍,试验结果为阴性。结论 苹果酸舒尼替尼的3个杂质——杂质v-7、杂质v-1及杂质E均可以按照非遗传毒性杂质进行控制。     

替格瑞洛中7个异构体的毒理评价及含量测定研究

目的 研究替格瑞洛中7个异构体的毒理性质,并建立高效液相色谱法对7个异构体的含量进行测定。方法 通过ADMET Predictor软件分析7个异构体的毒理性质,构建7个异构体的统一检验分析方法,并通过该方法对179批次样品的异构体含量进行测定。结果 替格瑞洛片中部分异构体存在肝脏毒性及小鼠致癌的可能性;建立的检验方法可以准确测定各异构体的含量且各异构体间分离度符合要求,179批次样品中7个异构体的含量均符合规定。结论 该系列异构体毒性预测均较小,但其实际效果需具体试验论证,该检验方法能系统地鉴别和测定各异构体的类型和含量,为统一替格瑞洛检验方法提供了重要的参考。     

高效液相色谱-高分辨轨道阱质谱联用法对兰索拉唑肠溶制剂的杂质谱研究

采用高效液相色谱-高分辨轨道阱质谱联用检测方法,建立二维在线除盐检测方法对兰索拉唑肠溶制剂法定检验条件下检出的杂质进行结构推定,建立兼容质谱检测器的色谱方法对法检方法无法分离的杂质进行测定和结构推定,检出杂质结构的鉴定方法根据有无杂质对照品而异来推定其结构,以此考察不同企业间产品杂质谱的差异性。二维在线除盐方法的一维色谱条件同《中华人民共和国药典》（2020版）有关物质项下,二维质谱条件采用Waters C₁₈ T3（2.1 mm × 100 mm,1.7 μm）色谱柱,0.1%甲酸水-乙腈流动相,梯度洗脱。兼容质谱的色谱条件采用Agilent Extend C₁₈（4.6 mm × 150 mm, 5 μm）色谱柱,流动相A相：25 mmol/L乙酸铵,B相：25 mmol/L乙酸铵-乙腈（1∶4）[用冰乙酸调节pH至6.5],梯度洗脱。二维在线除盐方法检出杂质9个,其中5个为已知杂质A ~ E,4个为未知杂质。兼容质谱检测器方法检出杂质14个,其中9个为未知杂质（4个与二维在线除盐方法结果一致,5个为该条件下新检出）。对未知杂质的结构进行了推测和来源归属。本文建立的两个高效液相色谱-高分辨轨道阱质谱联用检测方法对兰索拉唑制剂的质量控制和工艺评价具有指导意义。     

高效液相色谱串联质谱法测定氯沙坦钾中的遗传毒性杂质N-亚硝基-N-甲基-4-氨基丁酸

目的建立了一种高效液相色谱-三重四极杆串联质谱法,对氯沙坦钾原料药中遗传毒性杂质N-亚硝基-N-甲基-4-氨基丁酸(NMBA)进行测定。方法色谱柱为岛津Shim-pack XR-ODSⅡ色谱柱(2.0 mm×150 mm,2.2μm),流动相为0.1%甲酸水溶液(A)和甲醇(B),进行梯度洗脱,流速0.3 mL·min^-1,柱温为40℃,采用ESI离子化-三重四极杆质谱多反应监测(MRM)正离子模式检测,碰撞电压分别为-11,-13和-13 V,碰撞气氩气270 kPa,NMBA的离子对分别为m/z 147.15→117.10,147.15→87.10和147.15→44.10。结果该方法中NMBA在1~100 ng·mL^-1内线性关系良好,日内和日间的保留时间和峰面积的重复性良好(RSD均小于1.10%,n=6和n=18),低、中、高3个浓度的平均回收率在94.40%~98.04%之间。结论本方法简单方便,可快速有效的对氯沙坦钾原料药中NMBA进行限度检查并实现定量分析。     

盐酸环丙沙星纯化中微量有机杂质的分离与结构研究

用液相色谱法检测盐酸环丙沙星原药，发现一杂质峰。该杂质经分离，确证其结构为７－氯－１－环丙基－６－（１－哌嗪基）－１，４－二氢－４－氧代喹啉－３－羧酸盐酸盐（３）。     

埃索美拉唑及其光学异构体的亲和毛细管电泳手性拆分

以牛血清白蛋白为手性添加剂,建立埃索美拉唑对映体杂质检查的亲和毛细管电泳方法,并采用荧光光谱、圆二色光谱法,通过研究埃索美拉唑及光学异构体与牛血清白蛋白作用的热力学参数、焓熵驱动过程及蛋白构象变化对其拆分机理进行探讨。建立的电泳分离条件为:未涂层石英毛细管柱(50 cm×50 μm,有效长度41.5 cm),以pH 8.0的20 mmol/L磷酸二氢钠-磷酸氢二钠缓冲液(含250 μmol/L牛血清白蛋白和7%正丙醇)作为运行缓冲液,正向运行电压30 kV,柱温25 ℃,检测波长302 nm,压力进样(5 kPa,5 s)。在优化的实验条件下,埃索美拉唑与其对映体的分离度大于1.8,对映体杂质的最低检测限和定量限分别为0.8和2.0 μg/mL,在2~20 μg/mL浓度范围内线性关系良好;平均回收率为100.4%,RSD小于2.0%。该方法可用于埃索美拉唑原料药的对映体杂质检查。