Development of quantitative HPTLC-densitometry methods following a model approach for transfer of TLC screening methods for pharmaceutical products of atenolol,chloramphenicol, furosemide,glibenclamide, penicillin V potassium,and praziquantel

Transfer of six thin-layer chromatography (TLC) Global Pharma Health Fund E.V. Minilab manual protocols for detecting fake drugs in pharmaceutical products to quantitative high-performance TLC (HPTLC)-densitometry methods was performed following a previously published model process. The developed and validated methods for tablets or capsules containing atenolol, chloramphenicol, furosemide, glibenclamide, penicillin V potassium, and praziquantel involved use of a limited list of inexpensive, relatively nontoxic, readily available solvents and other reagents; silica gel 60?F₂₅₄ plates; automated bandwise sample and standard solution application; ascending mobile phase development of plates in a chamber; and automated slit scanning densitometry for detection, identification, and quantification. Validation data for methods developed in an early version of the transfer model process that did not include standard addition validation are reported for pharmaceutical products containing amitriptyline HCl, amodiaquine, diphenhydramine HCl, and mebendazole.     

水-氯涂膜剂中氯霉素体内外透皮释放评价

采用HPLC法测定自制水杨酸-氯霉素普鲁兰糖涂膜剂中氯霉素含量,对涂膜剂中氯霉素进行体内外透皮释放行为研究.选取昆明种小鼠鼠皮,用立式扩散池评价涂膜剂中氯霉素体外释放行为.自制涂膜剂中氯霉素体外释放缓慢,释放过程可用Higuchi方程模拟.选用新西兰兔背敷涂膜剂,测定兔体内氯霉素的药-时曲线,并考察超声促透效果.兔体内药-时曲线显示,氯霉素血药质量浓度1h达峰,峰值1.24μg/mL;超声处理兔表皮后涂敷涂膜剂,药-时曲线下面积(AUC)大于未经超声处理组.自制涂膜剂缓慢释放氯霉素,可用于局部治疗,超声处理兔表皮可促进氯霉素的透皮吸收.水-氯普鲁兰糖涂膜剂中氯霉素体内外释放具有相关性,体外释放度可预测体内药物吸收情况.     

NIR‐FT Raman,FT‐IR and surface‐enhanced Raman scattering spectra,with theoretical simulations on chloramphenicol

Chloramphenicol (CLM), originally derived from the bacterium Streptomyces venezuelae, is an inhibitor of bacterial ribosomal peptidyl transferase activity. The near infrared Fourier transform (NIR‐FT) Raman, surface‐enhanced Raman spectroscopy (SERS) and Fourier transform infrared (FT‐IR) spectral analyses of CLM, a potential antibacterial drug for the treatment of typhoid fever, were carried out along with density functional computations. The vibrational spectral analysis reveals that the CH₂ asymmetric and symmetric stretching modes are shifted to higher wavenumbers than the computed values, owing to the electronic effects resulting from induction of methylene group with the adjacent electronegative atom. The lowering of CO stretching wavenumber is due to the presence of the strong electronegative atom, nitrogen, attached to the carbonyl carbon, causing large degree of molecular π‐electron delocalization and redistribution of electrons, which weakens the CO bond. The absence of a C H stretching vibration and the observed C H out‐of‐plane bending modes suggest that the CLM molecule may be adsorbed in a flat orientation with respect to the silver surface. Copyright © 2008 John Wiley & Sons, Ltd.     

氯霉素包合物的拉曼光谱和红外光谱研究

研究应用拉曼光谱法分析验证氯霉素包合物的可行性。采用拉曼光谱仪和傅里叶红外光谱仪分别测得β-环糊精、氯霉素、β-环糊精和氯霉素物理混合物、氯霉素包合物四种物质固体粉末的拉曼图谱和红外图谱, 并对其进行对照分析。 结果表明拉曼光谱法可获得与红外光谱法一致的结果, 结果表明氯霉素的苯环结构和易水解基团二氯乙酰胺基通过氢键作用被包裹在β-环糊精的空穴结构中形成包合物, 增加了氯霉素的稳定性和溶出度, 并且拉曼光谱法具有快速、准确、简便、无损测量等显著优势, 可作为验证药物包合物的形成重要手段。     

Covalently bonded aptamer‐functionalised magnetic mesoporous carbon for high‐efficiency chloramphenicol detection

A novel aptamer‐modified magnetic mesoporous carbon was prepared to develop a specific and sensitive magnetic solid‐phase extraction method through combination with ultra‐high performance liquid chromatography‐tandem mass spectrometry for the analysis chloramphenicol in complex samples. More specifically, the chloramphenicol aptamer‐modified Mg/Al layered double hydroxide magnetic mesoporous carbon was employed as a novel magnetic solid‐phase extraction sorbent for analyte enrichment and sample clean‐up. The extraction solvent, extraction time, desorption solvent, and desorption time were investigated. It was found that the mesoporous structure and aptamer‐based affinity interactions resulted in acceptable selective recognition and a good chemical stability toward trace amounts of chloramphenicol. Upon combination with the ultra‐high performance liquid chromatography‐tandem mass spectrometry technique, a specific and sensitive recognition method was developed with a low limit of detection (0.94 pmol/L, S/N = 3) for chloramphenicol analysis. The developed method was successfully employed for the determination of chloramphenicol in complex serum, milk powders, fish and chicken samples, giving recoveries of 87.0‐107% with relative standard deviations of 3.1‐9.7%.     

高效液相色谱-串联质谱法测定蜂胶原胶中氯霉素的残留量

建立了高效液相色谱-串联质谱法(HPLC-MS/MS)测定蜂胶原胶中氯霉素残留量的分析方法。样品用叔丁基甲醚溶解,氢氧化钠溶液去除黄酮类等杂质,叔丁基甲醚层加正己烷降低氯霉素的溶解度,再用乙酸钠缓冲液反萃氯霉素,反萃溶液调至碱性后用乙酸乙酯萃取,经浓缩、复溶和过滤后,进行测定。采用甲醇-水(65∶35,体积比)为流动相,反相Atlantis T_3色谱柱进行液相色谱分离,电喷雾负离子电离(ESI-),多反应监测模式(MRM)进行检测,内标法定量。结果表明,氯霉素在0.1~5.0μg/L范围内线性关系良好;方法的定量下限(S/N≥10)为0.3μg/kg;在0.3、0.6、3.0μg/kg加标水平下,氯霉素的平均回收率为97.3%~103%,相对标准偏差为4.8%~6.4%。该法的灵敏度、准确度和精密度均符合兽药残留检测的要求。     

基于分子印迹膜的检测牛奶中琥珀酸氯霉素残留传感方法的研究

采用光聚合法在一次性丝网印刷电极上制备琥珀酸氯霉素分子印迹膜,然后将丝网印刷电极通过电极插口与电化学分析装置相连接,组装成检测琥珀酸氯霉素残留的电化学传感仪.使用与传感装置相连接的记录仪记录响应的结果.采用本传感仪建立了检测氯霉素的标准曲线并测试了实际牛奶样品中氯霉素含量.电镜学观察表明,与非印迹膜相比,在印迹膜表面形成大量直径约为100 nm的印迹微孔.本传感仪装置检测琥珀酸氯霉素具有很高的灵敏度和特异性,检出限为2×10-9 mol/L,检测线性范围为1×10-8～1.2×10-5 mol/L,基于牛奶样品的检测回收率介于93.5%～95.5%之间.     

紫外联用高级氧化技术降解氯霉素试验研究

为了实现紫外高级氧化技术在实际水处理中去除抗生素的应用,以氯霉素(CAP)为研究对象,对比了静态试验中紫外技术,连续流下单独紫外技术、紫外高级氧化技术(UV/H2O2、UV/PS)对氯霉素的去除效能.进一步分析了连续流下紫外光强、紫外光波长、停留时间、氧化剂投加量、氯霉素初始浓度和原水水质等因素对去除效果的影响.研究发...     

海洋病原细菌Enterobacter sp. EM28-2P -存在氯霉素磷酸化灭活机制

报道1例非氯霉素产生菌中发现的氯霉素磷酸化灭活机制.海洋病原细菌Enterobacter sp. EM28-2P -(Cm r,cat -,MIC=25 μg/mL)接种在含25 μg/mL标准品D-(-)-氯霉素LB培养基中培养24 h后,可生成磷酸化氯霉素.LC-MS分析检测出新生成3个离子峰m/z 400.9,402.8和404.9,都是典型[M PO 3 -H] -的特征指纹峰,对应于氯霉素的C3位羟基磷酸化产物.