麦饭石修饰碳糊电极伏安法测定克林霉素

在pH=9的磷酸盐缓冲溶液(PBS)中,用麦饭石修饰碳糊电极循环伏安法研究了克林霉素的电化学性质,并讨论了影响克林霉素测定的各种因素,得到了其测定的最佳实验条件。克林霉素的氧化峰电位是0.80V,氧化峰电流与克林霉素的浓度在3.25×10-6～1.10×10-4 mol.L-1范围内呈良好的线性关系。该测定方法的检出限(S/N=3)为5.0×10-7 mol.L-1。用标准加入法测定回收率范围在94.9%～101.4%。克林霉素在0.80V处的氧化为1电子、1质子参加的受扩散控制的不可逆过程。克林霉素的电化学测定方法能很好地用于实际样品的测定而且结果与药典法一致。     

高效液相色谱法同时检测祛痘类化妆品中12种禁限用物质

建立了反相高效液相色谱同时测定祛痘类化妆品中12种禁限用物质(依诺沙星、环丙沙星、氧氟沙星、林可霉素、克林霉素、克林霉素磷酸酯、氯霉素、氯霉素二醇物、磺胺甲口恶唑、甲硝唑、替硝唑、水杨酸)的方法。样品经甲醇与0.1 mol/L盐酸混合溶液(体积比1∶1)超声提取,采用ACEC18(250 mm×4.6 mm,5μm)色谱柱分离,以乙腈-0.025 mol/L磷酸三乙胺溶液二元流动相梯度洗脱,流速1.5 mL/min,柱温40℃,采用二极管阵列检测器双波长(210、277 nm)检测,外标法定量。林可霉素、克林霉素、克林霉素磷酸酯3种成分的线性范围为25～1 000mg/L,其他9种成分的线性范围为5～200 mg/L,相关系数均大于0.997。12种禁限用物质的方法检出限为5～50μg/g,平均回收率为88%～115%,相对标准偏差为0.4%～3.0%。该方法操作简便、准确、灵敏,适用于祛痘类化妆品中12种禁限用物质的测定。     

高效液相色谱法测定化妆品中林可霉素类药物

林可霉素类药物属抗菌药物中的小类别,临床上广泛用于除神经系统之外的敏感菌所致的各种感染,主要有以盐酸盐或磷酸酯形式存在的林可霉素和克林霉素类制剂。其不良反应也不容忽视[1],可引起胃肠道反应、肝脏损害、心血管反应等[2],我国在《化妆品卫生规范》中已将抗生素类药物列入化妆品禁用组分。近年来,祛痘或抑制粉刺化妆品中非     

微流控芯片非接触电导检测法快速测定盐酸克林霉素的含量

建立了微流控芯片非接触电导检测法快速测定盐酸克林霉素胶囊中盐酸克林霉素的方法。考察了缓冲液种类和浓度、添加剂种类、分离电压以及进样时间等因素对分离检测的影响。以2.0 mmol·L-1HAc+2.0 mmol·L-1Na Ac为缓冲溶液,分离电压为1.5 k V,进样时间15.0 s,在1.0 min内实现了对盐酸克林霉素的快速分离测定。盐酸克林霉素的线性范围为20.0~200.0μg·m L-1,相关系数(r)为0.999 2,检出限(S/N=3)为5.0μg·m L-1,相对标准偏差为2.1%,加标回收率为95.9%~103%。该方法简便、快速,可为盐酸克林霉素检测提供新的方法和技术。     

联吡啶钌体系电化学发光法测定克林霉素的研究

建立了以金电极为工作电极电致化学发光测定盐酸克林霉素的方法,并采用循环伏安和电致化学发光法,研究了体系的电化学行为和电化学发光行为.研究结果表明,在0.1 mol/L的硼酸(pH 8.0)缓冲溶液中,扫描速率为100 mV/s时,ECL的峰高与盐酸克林霉素浓度在1.0×10-5 ～1.0×10-4 mol/L和1.0×10-7 ～8.0×10-6 mol/L范围内呈线性关系,其线性回归方程分别为I(counts)=465.00×105c-133.80(r=0.996 8)和I(counts)=20.333×106c+100.25(r=0.995 9).方法的检出限为1.0×10-7 mol/L(S/N=3).连续测定2.0×10-5 mol/L的盐酸克林霉素溶液10次,发光强度值的RSD为1.74%.对样品进行加标回收率实验,回收率为93% ～102%.该方法具有较高的选择性和灵敏度,样品处理简单快速,用于盐酸克林霉素胶囊的测定,结果满意.     

聚天青I/磁珠-纳米金修饰电极的制备及其对盐酸克林霉素的测定

制备了聚天青I/磁珠-纳米金修饰电极。在磷酸盐缓冲溶液(PBS)中,盐酸克林霉素在修饰电极上产生了灵敏的方波伏安氧化峰,峰电流与盐酸克林霉素浓度在一定的范围呈线性关系,线性回归方程为Ip=-3.0363×10-6-0.00255c,相关系数为0.9957,检出限8.5×10-6mol/L。     

钯（II）-克林霉素-卤代荧光素体系的共振瑞丽散射光谱及其分析应用

在pH为5.0-5.4的乙酸-乙酸钠缓冲溶液中,克林霉素（Clin）与钯(Ⅱ)形成螯合阳离子,它能进一步与二碘荧光素（DIF）,赤藓红（Ery）,曙红Y（EY）等卤代荧光素类染料反应形成1：1：1的三元离子缔合物,此时将引起吸收光谱变化和荧光猝灭,同时还导致共振瑞利散射(RRS)的急剧增强并产生新的RRS光谱,钯(Ⅱ)-克林霉素与DIF,Ery和EY形成产物的最大散射波长分别位于285,287,32 1nm处,另外还有些较弱的散射峰存在。散射增强（ΔI）与克林霉素浓度在一定范围内成正比,可用于克林霉素的定量测定。对于DIF,Ery和EY体系的线性范围和检出限分别为0.025-2.1μg•mL-1和7.8 ng•mL-1,0.053-2.4μg•mL-1和16.0 ng•mL-1;以及0.038-2.4μg•mL-1和11.0 ng•mL-1。本文研究了适宜的反应条件,考察了共存物质的影响,表明方法有较好的选择性,基于三元离子缔合物的RRS光谱,发展了一种高灵敏、简便快速测定克林霉素的新方法。文中还对离子缔合物的组成,结构和反应机理,以及离子缔合物对吸收,荧光和RRS光谱的影响进行了讨论。     

p53突变体Y220C小分子稳定剂的虚拟筛选

为了获得p53突变体的稳定剂,依次利用利宾斯基五原则,通过2次分子对接和全原子分子动力学(MD)模拟从Drug Bank 4.0数据库中筛选获得了潜在的稳定剂他克林.利用MD模拟进一步验证他克林和目标蛋白质之间的亲和作用.结果表明,他克林能够紧密结合到Y220C突变所形成的疏水空腔之中;他克林和目标蛋白质之间的主要作用力为疏水和静电相互作用,其中疏水相互作用占主导地位.此外,他克林分别与目标蛋白质的残基Leu145,Val147和Asp228形成3个氢键.基于MD模拟轨迹分析了他克林与p53CY220C的结合过程.由硫黄素T荧光光谱进一步证明他克林能够提高p53C-Y220C突变体的稳定性.     

超高效液相色谱-串联质谱法对动物源食品中13种林可胺类及大环内酯类药物残留的检测

建立了动物源食品中林可霉素、克林霉素、吡利霉素、红霉素、泰乐菌素、螺旋霉素、替米考星、竹桃霉素、吉他霉素、克拉霉素、阿奇霉素、罗红霉素和交沙霉素13种林可胺类和大环内酯类药物残留检测的超高效液相色谱-串联质谱分析方法.动物组织样品经乙腈提取后,用正己烷去除脂肪等杂质,然后用Waters Acquity UPLC BEH C18色谱柱分离,以乙腈和50 mmol/L乙酸铵水溶液为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测模式检测.结果表明:13种药物在5 ～200 μg/L范围内呈现良好的线性关系,相关系数R2均大于0.990,13种药物在动物组织中的检出限均为1 μg/kg,定量下限均为2.5 μg/kg.以2.5、25、100 μg/kg 3个水平进行回收实验,13种药物的回收率为72% ～104%,批内批间相对标准偏差为4.8% ～14.3%.     

固相萃取反相高效液相色谱法测定血浆中克林霉素的浓度

1　实验部分1.1　仪器、试剂及试药　　ＷａｔｅｒｓＡｌｌｉａｎｃｅ2690型高效液相色谱仪,包括2487型紫外双波长检测仪,Ｍｉｌｌｅｎｎｉｕｍ32数据处理系统以及ＤＥＬＬ微机等;美国ＳＵＰＥＬＣＯＶＩＳＩＰＲＥＰＴＭＤＬ固相萃取装置;Ｍｉｌｌｉ ｐｏｒｅ纯水系统。　　甲醇、乙腈和四氢呋喃为色谱纯;磷酸二氢钾为分析纯。　　受试者用药:普强苏州制药有限公司研制的盐酸克林霉素胶囊,每粒150ｍｇ,批号Ｓ20000907,检验号:苏字Ｓ0110;对照药:苏州第四制药厂生产的盐酸克林霉素胶囊,每粒150ｍｇ,批号990517。　　药物浓度测试用标准品:盐…     

Separation and characterization of clindamycin phosphate and related impurities in injection by liquid chromatography/electrospray ionization mass spectrometry

A simple high‐performance liquid chromatography/electrospray ionization tandem mass spectrometric (HPLC/ESI‐MS/MS) method has been developed for the rapid identification of clindamycin phosphate and its degradation products or related impurities in clindamycin phosphate injection. Detection was performed by quadrupole time‐of‐flight mass spectrometry (Q‐TOFMS) via an ESI source in positive mode. Clindamycin phosphate and its related substances lincomycin, 7‐epilincomycin‐2‐phosphate, lincomycin‐2‐phosphate, clindamycin B, clindamycin B‐2‐phosphate, and clindamycin were identified simultaneously by HPLC/ESI‐MS/MS results. Based on the MS/MS spectra of their quasi‐molecular ions, the fragmentation pathways of clindamycin phosphate and its related substances were compared and proposed, which are specific and useful for the identification of the lincosamide antibiotics and related impurities. The method was rapid, sensitive and specific and can be used to identify clindamycin phosphate and its related impurities in clindamycin phosphate injection without control compounds. Copyright © 2009 John Wiley & Sons, Ltd.     

Simultaneous determination of tretinoin and clindamycin phosphate and their degradation products in topical formulations by reverse phase HPLC

A new HPLC method based on reverse phase separation and photodiode-array detection has been developed for the simultaneous determination of tretinoin and clindamycin phosphate, and their degradation products in topical formulations. The method has been shown to be stability indicating, accurate, and precise for two different formulation vehicles. Separation was achieved on a reverse phase C18 column (Lichrospher, RP18, 5 microm, 25 cm x 4.6 mm ID, Phenomenex, USA) using a simple gradient with aqueous-acetonitrile and aqueous-methanol mobile phases. The method recovery averaged 100.3% for tretinoin and 99.6% for clindamycin phosphate at a concentration range between 80% and 120% of the label claim. The method can be applied to assess the stability of tretinoin and clindamycin phosphate in pharmaceutical formulations containing tretinoin and clindamycin phosphate individually or in combination as active drugs.     

Evaluation of the enantioseparation capability of the novel chiral selector clindamycin phosphate towards basic drugs by micellar electrokinetic chromatography

To date, a series of chiral selectors have been utilized successfully in capillary electrophoresis (CE). Among these various chiral selectors, macrocyclic antibiotics have been demonstrated to represent powerful enantioselectivity towards many chiral compounds. Differing from macrocyclic antibiotics, the use of lincosamide antibiotics as chiral selectors has not been reported previously. In our recent work, clindamycin phosphate belonging to the group of lincosamides has been first used as a chiral selector in capillary zone electrophoresis (CZE). In this paper, a micellar electrokinetic chromatography (MEKC) method has been developed for the evaluation of enantioseparation capability of this novel chiral selector towards several racemic basic drugs. As observed during the course of this work, clindamycin phosphate allowed excellent separation of the enantiomers of nefopam, citalopram, tryptophan, chlorphenamine, propranolol and metoprolol, as well as partial enantioresolution of tryptophan methyl ester and cetirizine. In this MEKC chiral separation system, different types of anionic surfactants, organic additives and background electrolytes were tested, and satisfactory enantioseparations of basic drugs above-mentioned were achieved using sodium dodecyl sulfate (SDS) as the surfactant, isopropanol as the organic additive, and phosphate as the background electrolyte. Furthermore, both migration times and enantioseparation of the analytes were influenced by several experimental parameters such as pH of the BGE, clindamycin phosphate and SDS concentrations, phosphate and isopropanol concentrations, and applied voltage. Consequently, the effects of these factors on enantioseparations of the studied basic drugs were systematically investigated in order to evaluate the stereoselectivity of clindamycin phosphate in MEKC.     

Investigation of enantiomeric separation of basic drugs by capillary electrophoresis using clindamycin phosphate as a novel chiral selector

A wide number of chiral selectors have been employed in CE and among them macrocyclic antibiotics exhibited excellent enantioselective properties toward plenteous racemic drugs. Different from macrocyclic antibiotics, the use of lincomycin antibiotics as chiral selectors has not been reported previously. In this study clindamycin phosphate belonging to the group of lincomycin antibiotics is first used as a novel chiral selector for the enantiomeric separations of several racemic basic drugs, which possess high separability, consisting of nefopam, citalopram, tryptophan, chlorphenamine and propranolol. Other basic drugs giving partial enantioseparation include tryptophan methyl ester, metoprolol and atenolol. Clindamycin phosphate possesses advantages such as high solubility and low viscosity in the water and very weak UV absorption. In the course of this work we observed that both migration time and enantioseparation were influenced by several parameters such as pH of the BGE, clindamycin concentration, capillary temperature, applied voltage and organic modifier. The optimum pH that was in the neutral or weak basic region but varied among drugs, a low capillary temperature and a clindamycin concentration of 60 or 80 mM are recommended as the optimum conditions for chiral separation of these drugs. Moreover, comparison of the influences of the studied parameters was further investigated by means of Statistical Product and Service Solutions in this paper.     

Determination of free clindamycin,flucloxacillin or tedizolid in plasma: Pay attention to physiological conditions when using ultrafiltration

Pharmacokinetic/pharmacodynamic indices of anti-infective drugs should be referenced to free drug concentrations. In the present study, clindamycin, flucloxacillin and tedizolid have been determined in human plasma by HPLC–UV. The drugs were separated isocratically within 3–6 min on a C₁₈ column using mixtures of phosphate buffer–acetonitrile of pH 7.1–7.2. Sample treatment for the determination of total drug concentrations in plasma included extraction/back-extraction (clindamycin) or protein precipitation (flucloxacillin, tedizolid). The free drug concentrations were determined after ultrafiltration. An ultrafiltration device with a membrane consisting of regenerated cellulose proved to be suitable for all drugs. Maintaining a physiological pH was crucial for clindamycin, whereas maintaining body temperature was essential for tedizolid. The methods were applied to the analysis of total and free drug concentrations in clinical samples and were sufficiently sensitive for pharmacokinetic studies and therapeutic drug monitoring.     

Effect of concentration polarization on electrodialytic concentrating of dilute NaCl and NH4NO3 solutions

Electrodialytic concentrating of dilute sodium chloride and ammonium nitrate solutions is studied in a wide range of current densities. Using the model of limiting electrodialytic concentrating, based on the experimental data, the transport characteristics of MK-40/MA-40 membrane pair in the above electrolytes and the hydration numbers of these electrolytes were determined. It is found that a degree of concentration polarization has an effect on the main parameters of limiting electrodialytic concentrating: the current efficiency, the water transfer number across the test membrane pair, and the concentration of solution in the concentrating compartment. These parameters determine the effectiveness of concentrating. It is found that the electrodialytic concentrating is most effective at the limiting current due to the lowest electroosmotic permeability of membrane pair and the highest current efficiency.     

Improvement of the technology for processing of sulfate solutions produced in the stage of sulfuric acid breakdown of beryllium ore concentrates

The possibility of purifying a sulfate solution to remove silicon and calcium by concentrating beryllium in this solution was studied.     

Postulating Modes of Action of Compounds with Antimicrobial Activities through Metabolomics Analysis

Strains of Staphylococcus aureus and coagulase-negative Staphylococcus with different antibiotic susceptibilities were selected to be the test targets of four synthesized compounds of N-aryl-4-guanidinomethylbenzoates and N-aryl-4-guanidinobenzamides. Minimum inhibitory concentrations of the four compounds showed comparable results to 13 commercial antibiotics. Metabolomics analysis based on GC–MS indicated that the four compounds shared the similar antimicrobial mechanism with clindamycin, but K–B disc diffusion tests implied that their exact binding site might be different from clindamycin or the current macrolide resistance mechanisms had no effect on the actions of synthesized compounds. The major effects of the studied compounds on the intercellular metabolites of S. aureus were the increased intracellular d-glucose, proline, phosphate and propanoic acid concentrations. This study proved metabolomics analysis was a promising tool in antibiotic mechanism research.     

羟甲基丙烯酰胺交联纤维素高吸水材料及其应用

研究了羧甲基纤维素经N-羟甲基丙烯酰胺交联制取的高吸水材料的产品性能，及交联剂用量对吸附性能的影响．将吸水材料与透析法结合用于蛋白质溶液的脱水浓缩，一般6小时可浓缩2．9～3．7倍，若在中间换过两次吸水剂，则在4小时内可浓缩5．6倍。