色谱柱分类数据库用于指导天然药物化学对照品色谱纯度测定时色谱柱理性选择（英文）

由于中药化学对照品多数来源于动植物药材,很容易混有结构类似物,故有机杂质测定是可能影响其化学对照品赋值准确性的关键风险因素。中药化学对照品的有机杂质测定通常采用药典收载或文献报道的高效液相色谱法,这些方法通常仅规定"以十八烷基硅烷键合硅胶为填充剂",无适宜色谱柱的品牌信息,或者实验室无文献所用的色谱柱品牌,而目前市场上已有800多种品牌的C18柱,生产工艺的不同导致不同品牌C18柱的选择性有差异,甚至差异显著。这很容易出现由于色谱柱选择不适宜而导致测定结果不准确的风险。该文采用国外色谱柱分类数据库指导对照品纯度考察时色谱柱的理性选择,尽可能减少色谱柱盲选可能导致的纯度结果不准确的风险。首先,用数据库挑选2根选择性差异显著的色谱柱(选择性因子F≥6)进行平行实验,以尽可能反映采用不同品牌色谱柱可能出现的分离效果差异。如果这2根色谱柱的分离效果及纯度测定结果无显著性差异,则可以交叉验证该对照品纯度测定的准确性。否则需要从数据库中选择另外1根与之前试验中分离效果更好、选择性相似的色谱柱进行纯度结果验证。在N-反式-p-对香豆酰基酪胺和表儿茶素没食子酸酯首批对照品的纯度考察中,使用了上述策略并验证了其有效性和科学性,计划推广应用至更多的中药化学对照品,特别当其可能含碱性或弱酸性化合物时,更应该尝试采用本文推荐的色谱柱选择策略交叉验证其纯度测定结果的准确性。

Facilitated column selection in the separation of acetylspiramycin components using a simple column classification system

Acetylspiramycin（ASPM）,a 16-membered basic macrolide antibiotic,is the acetylated derivative of spiramycin.In addition to the four main components,more than seventy minor components could be present in ASPM.Thus,it is a challenge to obtain a baseline separation of ASPM components.Meanwhile,in some cases it was found that the results obtained by different brands of C_（18） columns were significantly different,indicating the necessity of a rational column selection for the separation of ASPM components.In this paper,we attempted to facilitate column selection for the analysis of ASPM using the database of the column characterization system established by Leuven University.With the CAPCELL PAK MG C_（18）（250 mm×4.6 mm,5μm） as the reference column,three groups of columns（F2 group：similar selectivity;2F6：intermediate ranked group;F6 group： different selectivity,compared to the reference column） were selected,and their performances in the separation of ASPM components were evaluated under the chromatographic conditions described in Chinese Pharmacopoeia monograph.A good relationship was demonstrated between the ranking of columns and their selectivity in the separation of ASPM components,indicating the column classification system established by Leuven University was a helpful tool in the selection of suitable columns for the analysis of ASPM,a complex mixture of basic compounds.

Impurity analysis of gentamicin bulk samples by improved liquid chromatography-ion trap mass spectrometry

Several gentamicin bulk samples from different origins were investigated using an LC/MS method.LC equipped with ion trap MS with positive ionization was performed on a Capcell Pak C18(AQ) column with the mobile phase containing 50 mM trifluoroacetic(TFA) and methanol.Impurities present in batches of gentamicin bulk samples were elucidated and compared according to their fragmentation behavior.In total seventeen impurities present in samples,five impurities were not elucidated and two compounds were identified preliminarily.It was observed that the impurity profiles were different in samples from different origins which indicate necessity in the quality control of gentamicin.

甲硝唑光降解杂质的研究及对药典有关物质方法的优化建议

目的:对采用现有各国药典中甲硝唑有关物质方法考察甲硝唑强光照射影响因素试验出现的物料不平衡(甲硝唑降解程度明显高于有关物质增长幅度)的原因进行调查。方法:用液相色谱-二极管阵列检测-串联质谱法(LC PDA-MS)对强光破坏的甲硝唑水溶液及其复方阴道洗剂的光降解产物进行定性鉴别和紫外光谱研究;用推导结构(N-(2-羟乙基)-5-甲基-l, 2,4-(口恶)二唑-3-甲酰胺)的杂质对照品,通过与甲硝唑光降解杂质保留时间和提取PDA光谱的一致性对比,及与甲硝唑氢谱的平行比较,对推导的甲硝唑光降解杂质结构进行确证;根据定性和光谱研究结果,依据现有药典方法优化了能同时检测该光降解杂质的方法并进行全面方法学验证。结果:甲硝唑在溶液、紫外光照条件下容易发生光降解,该杂质最大吸收约在230 nm,而在各论项下有关物质方法中设置的315/319 nm处吸收强度很弱。已上市甲硝唑注射液(需要缓慢输液)在室温光照条件下放置48 h或在5 000 lx条件下处理2 d和5 d后,光降解产物的量从“未检出”快速增加至0.15%、0.36%和0.88%,均超过本品的鉴定限(0.10%)和界定限(0.15%)。用230 nm检测并引入梯度洗脱、在各论项方法基础上优化建立的方法,能同时检测该光降解杂质和甲硝唑特定杂质2-甲基-5-硝基咪唑,方法的专属性、灵敏度、精密度、溶液的稳定性等指标均满足要求。结论:通过对甲硝唑光降解杂质的结构鉴定和光谱特征研究,揭示了采用现有药典检查方法考察甲硝唑光破坏样品出现的物料不平衡原因;建立了能同时控制该光降解杂质和甲硝唑现有特定杂质的优化方法;甲硝唑注射液慢速输液过程存在较大的光降解风险,需引起关注。