LC-HR-MS/MS法鉴定头孢丙烯干混悬剂中的未知杂质

目的:检测头孢丙烯干混悬剂中的未知杂质,并对其进行结构鉴定。方法:采用高效液相色谱-串联高分辨质谱法检测并鉴定头孢丙烯干混悬剂中的未知杂质。色谱柱为Thermo HyPURITYTMC18,流动相为乙腈-0.013%甲酸水溶液(梯度洗脱),检测波长为230 nm,流速为1.0 m L/min,柱温为40℃,进样量为20μL;以电喷雾离子源行正离子全扫描,扫描范围为质荷比(m/z)100~1500,喷雾电压为3.8 kV,金属毛细管温度为320℃,鞘气压力为60 Arb,辅助气压力为10 Arb,喷雾温度为280℃。结果:在该色谱条件下,杂质K的检测限为0.202μg/mL,精密度、重复性试验的RSD均小于4%。杂质K附近发现3个未知杂质,且互为异构体,离子保留时间为17.83~19.31 min,二级母离子均为m/z 436.1500[M+H]+,可能为头孢丙烯开环、脱水后的产物。结论:本方法检测出头孢丙烯干混悬剂中杂质K附近的3个未知杂质。     

青霉素杂质谱分析方法的优化与转换

目的建立青霉素杂质谱HPLC分析方法,并将其转换成UPLC/UHPLC方法。方法以青霉素混合降解溶液为样品;首先分析《中国药典》(2010年版,ChP2010)方法甲醇-缓冲盐二元流动相色谱系统的缺陷;再利用实验设计理念,以响应曲面法(response surface methodology,RSM)的中心组合设计(central composition design,CCD)对色谱系统进行优化,满意度函数法确定最优色谱条件,并优化梯度洗脱条件;最后,利用软件对HPLC方法的流速、进样体积和梯度时间进行几何缩放,并通过色谱柱的选择,将其分别转换为UPLC方法和UHPLC方法。结果新HPLC方法:色谱柱为Capcell Pak C18 MGII(4.6mm×250mm,5μm),流速:1.0m L/min,进样体积:20μL;UPLC方法:色谱柱为Cortecs C18(2.1mm×100mm,1.6μm),流速:0.35m L/min,进样体积:2.0μL;UHPLC方法:Cortecs C18(4.6mm×150mm,2.76μm),流速:0.8mL/min,进样体积:10μL。3种方法的检测波长均为225nm,柱温均为34℃;流动相A均为磷酸盐缓冲液(取磷酸二氢钾10.6g,加水至1000mL,用磷酸调pH至3.4)-甲醇(72:14,V/V),流动相B均为乙腈;均为梯度洗脱,但梯度洗脱表不同。结论 3个色谱系统的分离效果(出峰顺序和个数)相似。新HPLC方法可以分离出更多的降解杂质,并明显改善了青霉素峰的拖尾,缩短了分析时间。     

二维超高效液相色谱质谱联用技术测定注射用头孢地嗪钠的杂质谱

目的 建立二维超高效液相色谱质谱联用法研究注射用头孢地嗪钠的杂质谱。方法 一维色谱采用Waters HSS T3 C18(100mm×2.1mm, 1.8μm);以磷酸盐缓冲液(取磷酸二氢钾0.87g,无水磷酸氢二钠0.22g,加水溶解并稀释至1000mL)为流动相A,乙腈为流动项B,梯度洗脱;柱温：35℃;流速：0.4mL/min;检测波长：215nm;进样量：3μL;二维色谱采用Waters BEH C18(50mm×2.1mm, 1.7μm);以0.1%甲酸水溶液为流动相A,0.1%甲酸的乙腈为流动项B,切峰后开始B相3min由2%到95%;柱温：35℃;流速：0.4mL/min;质谱采用Xevo G2-XS QTof MS系统,离子源为ESI源,离子源温度：110℃,毛细管电压：3.0KV,雾化器温度：450℃,雾化器流速：800L/h,扫描范围：m/z 100~2000,测定头孢地嗪主要杂质的一级和二级质谱,进行结构解析。结果 采用UPLC梯度洗脱方法可检出多种头孢地嗪异构体、降解杂质和高分子杂质等,检出杂质的个数和总量均较现行法定标准多。结论 本品的杂质在原料合成、制剂分装及运输储藏过程中均可产生,因此,应对原料和制剂生产过程中的关键技术指标和环境条件加以控制。     

Simultaneous detection and quantitation of organic impurities in methamphetamine by ultra‐high‐performance liquid chromatography–tandem mass spectrometry,a complementary technique for methamphetamine profiling

The analysis of organic impurities plays an important role in the impurity profiling of methamphetamine, which in turn provides valuable information about methamphetamine manufacturing, in particular its synthetic route, chemicals, and precursors used. Ultra‐high‐performance liquid chromatography – tandem mass spectrometry (UHPLC – MS/MS) is ideally suited for this purpose due to its excellent sensitivity, selectivity, and wide linear range in multiple reaction monitoring (MRM) mode. In this study, a dilute‐and‐shoot UHPLC – MS/MS method was developed for the simultaneous identification and quantitation of 23 organic manufacturing impurities in illicit methamphetamine. The developed method was validated in terms of stability, limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, and precision. More than 100 illicitly prepared methamphetamine samples were analyzed. Due to its ability to detect ephedrine/pseudoephedrine and its high sensitivity for critical target markers (eg, chloro‐pseudoephedrine, N‐cyclohexylamphetamine, and compounds B and P), more impurities and precursor/pre‐precursors were identified and quantified versus the current procedure by gas chromatography – mass spectrometry (GC – MS). Consequently, more samples could be classified by their synthetic routes. However, the UHPLC – MS/MS method has difficulty in detecting neutral and untargeted emerging manufacturing impurities and can therefore only serve as a complement to the current method. Despite this deficiency, the quantitative information acquired by the presented UHPLC – MS/MS methodology increased the sample discrimination power, thereby enhancing the capacity of methamphetamine profiling program (MPP) to conduct sample‐sample comparisons.     

A developed HPLC method for the determination of Alogliptin Benzoate and its potential impurities in bulk drug and tablets

Alogliptin (AGLT), active ingredient of Alogliptin Benzoate (AGLT-BZ), is a new dipeptidyl peptidase-4 (DPP-4) inhibitor for the treatment of type 2 diabetes. This study aimed to build a suitable method to determine the potential related substances in AGLT-BZ bulk drug and tablets. Seven related substances in Alogliptin Benzoate substances were synthetized and identified by ¹H-NMR and ESI-MS. In addition, the impurities were detected by a gradient reverse-phase high performance liquid chromatography (RP-HPLC) with UV detection. The chromatographic system consisted of an Angilent Zobax SB-CN column (250 × 4.6 mm; 5 μm). The mobile phase consisted of water/acetonitrile/trifluoroacetic acid 1900:100:1 v/v/v (solution A) and acetonitrile/water/trifluoroacetic acid 1900:100:1 v/v/v (solution B) using a gradient program at a flow rate of 1.0 ml/min with 278 nm detection and an injection volume of 20 μl. Additionally, selectivity, the limit of quantitation (LOQ) and limit of detection (LOD), linearity, accuracy, precision and robustness were determined. Linearity was good over the concentration range 50–1000 ng/ml and the coefficient of determination (R²) were 0.9991–0.9998. RSD% of the determination of precision were <2% (n = 6). The method of RP-HPLC for the determination of impurities in AGLT-BZ was proved to be precise, accurate, robust and reliable. Three batches of self-made bulk drug and three dosages of commercial tablets were detected with this method.     

Cost-Effective Isolation of a Process Impurity of Pregabalin

Cost-effective isolation methods were developed on preparative HPLC, flash LC, and simulated moving bed (SMB) to prepare the process impurity, 3-(aminomethyl)-5-methylhex-4-enoic acid (4-ene impurity), of pregabalin. By a thorough experimental study on the different isolation techniques available, it was concluded that SMB was the most cost-effective. Hence, it was a continuous chromatography that utilized the advantage of SMB so that a high quantity of the impurity was generated in a short period of time. SMB was equipped with eight reversed-phased columns and was used to separate the process impurity of pregabalin. The effects of flow rate in zone 2 (Q2) and 3 (Q3), as well as switching time, on the operating performance parameters like purity, productivity, and desorbent consumption were studied. Operating conditions leading to more than 90% purity in the raffinate outlet stream were identified, together with those achieving optimal performance. All of these developed methods are novel, cost-effective, and can be applied to the isolation of other process- and stability-related impurities of pregabalin.     

RP-HPLC法测定酮洛芬凝胶中药物含量

目的建立酮洛芬凝胶中药物含量测定的方法,并明确光照对含量测定的影响。方法采用Diamonsil ODS柱(4.6 mm×200 mm,5μm);流动相为0.01 mol/L磷酸二氢钾溶液(用磷酸调pH值至3.0)-乙腈(50∶50),流速1.0 mL/min,检测波长为255 nm,柱温为室温。结果在本试验条件下,酮洛芬凝胶中与辅料及有关物质分离度均符合要求,酮洛芬进样量在0.525¹.575μg范围内线性关系良好(r=0.999 9,n=5),平均回收率为98.41%,RSD为1.35%(n=3)。经光照,酮洛芬含量明显降低,杂质A明显增加,杂质A为酮洛芬的光照降解产物。结论本方法简单、快捷,可用于酮洛芬凝胶中药物含量的测定。     

Identification and structural elucidation of process impurities generated in the end-game synthesis of taranabant (MK-0364) via cyanuric chloride

Taranabant (MK-0364) is a highly potent and selective cannabinoid-1 receptor (CB-1R) inverse agonist. It is being developed at Merck & Company to treat obesity. The chemical synthesis of MK-0364 drug substance involved the direct coupling of chiral amine and pyridine acid side chains mediated by cyanuric chloride. Four major process impurities were observed and characterized using high performance liquid chromatography (HPLC) coupled with ultraviolet (UV) and electrospray ionization (ESI) mass spectrometry (MS) detectors. The exact mass data was used for structural elucidation which suggests that the impurities are derivatives of cyanuric chloride formed in the coupling step. Owing to the reactive nature of these impurities, an interesting degradation phenomenon was observed during stability testing of MK-0364 drug substance when stored at 40 °C/75% RH and 25 °C/60% RH conditions. Degradation pathways were proposed to explain the changes observed in the HPLC impurity profile. Forced degradation experiments were also conducted to confirm the degradation pathways and assess the stability of the impurities. Finally, the complete stability data of the bulk drug are reported to support the hypothesis.     

Structural identification and characterization of potential degradants of zotarolimus on zotarolimus-coated drug-eluting stents

Identification and characterization of unknown zotarolimus impurities on zotarolimus-coated drug-eluting stents is an important aspect of product development since the presence of impurities can have a significant impact on quality and safety of the drug product. Four zotarolimus degradation products have been characterized by LC/UV/PDA, LC/MS, LC/MS/MS and NMR techniques in this work. Zotarolimus drug substance and zotarolimus-coated stents were subjected to degradation under heat, humidity, acid or base conditions. The HPLC separation was achieved on a Zorbax Eclipse XDB-C8 column using gradient elution and UV detection at 278 nm. All four impurities generated through the degradation were initially analyzed by LC/MS and/or LC/MS/MS for structural information. Then the isolation of these degradants was carried out by semi-preparative HPLC method followed by freeze-drying of the collected fractions. Finally the degradants were studied by ¹H and ¹³C NMR spectrometry. Based on LC/MS, ¹H NMR and ¹³C NMR data, the structures of these impurities were proposed and characterized as zotarolimus ring-opened isomer (1), zotarolimus hydrolysis product, 16-O-desmethyl ring-opened isomer (2) and zotarolimus lower fragment (3). Degradants 1, 2 and 3 have been observed on degraded zotarolimus-coated stent products.     

Separation and determination of nimesulide related substances for quality control purposes by micellar electrokinetic chromatography

A micellar electrokinetic chromatography (MEKC) method has been developed and validated for the determination of nimesulide related compounds in pharmaceutical formulations. Electrophoretic separation of six European Pharmacopoeia (EP) impurities (A–F) was performed using a fused silica capillary (L_eff. = 50 cm, L_tot. = 57 cm, 50 μm i.d.) with a background electrolyte (BGE) containing 25 mM borate buffer (pH 9.5), 30 mM sodium dodecyl sulphate and φ = 3% (v/v) acetonitrile. The influence of several factors (surfactant and buffer concentration, pH, organic modifier, applied voltage, capillary temperature and injection time) was studied. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. The calibration curves obtained for the six compounds were linear over the range 5–12 μg ml⁻¹ (0.05–0.12%). The relative standard deviations (s_r) of intra- and inter-day experiments were less than 5.0%. The detection limits ranged between 0.7 and 1.6 μg ml⁻¹ depending on the impurity. The proposed method was applied successfully to the quantification of nimesulide impurities in its pharmaceutical formulation.