药物脂水分配系数测定的微乳液电动色谱新方法研究

目的建立一种测定药物脂水分配系数的微乳液电动色谱(MEEKC)新方法，以避免测定时必须使用微乳相标记物，以及减小和评价测量误差。方法以系列化合物在MEEKC中的迁移时间t_m值与其脂水分配系数之间的关系，进行非线性拟合得出微乳相的虚拟迁移时间t_me，再建立标准曲线以测定所选取药物的脂水分配系数；从理论上评价测定结果准确度与t_m相关性，并以此评价测定结果的准确度。结果所选取的4种药物脂水分配系数的MEEKC测定值与摇瓶法测定值基本吻合，其平均差值为0.15，其测定准确度与t_m的相关性符合理论模型的分析。结论无微乳相标记物的MEEKC新方法简单、快速、可靠、重现性好，测定脂水分配系数的准确度较高，可用作药物脂水分配系数的测定。     

微乳色谱应用研究进展

微乳(Microemulsion,ME)是由乳化剂、助乳化剂、油相和水相组成的光学上各向同性,热力学稳定的液-液分散体[1],只要组分的比例合适即可自发形成均匀透明或微呈乳光的体系并保持稳定。以微乳为流动相进行的色谱称为微乳色谱[2]。微乳色谱近年来得到广泛研究和应用,其中微乳电动色谱的研究应用较多。本文简单介绍微乳的色谱行为,并就近年来微乳色谱的应用研究进展进行综述,主要介绍微乳电动色谱、微乳液相色谱、微乳薄层色谱、微乳毛细管电泳。1微乳的色谱行为微乳体系中由于引入表面活性剂,其亲水亲油性使得较大范围极性的物质都能在微乳中…     

硝苯地平微乳凝胶的制备及其质量评价

目的 将硝苯地平制备成微乳凝胶，以提高其生物利用度。方法 进行凝胶基质以及透皮吸收促进剂的筛选，确定硝苯地平微乳凝胶的最佳处方，并进行初步质量评价。结果 硝苯地平微乳的处方为乳化剂OP∶无水乙醇∶油酸乙酯∶水=27∶13.5∶4.5∶55；硝苯地平微乳凝胶的处方为1.2%卡波姆940，2.5%氮酮。所制得的硝苯地平微乳平均粒径为9.963 nm，大小均匀；硝苯地平微乳凝胶24 h的累积渗透量（Q_{24 h}）达到（296.35±34.66）μg·cm^-2，稳态透皮速率为（14.20±0.23）μg·cm^-2·h^-1；经高速离心、低温、高温试验考察，硝苯地平微乳凝胶稳定性良好；经小鼠皮肤刺激性试验考察，硝苯地平微乳凝胶对皮肤刺激性和毒性较小。结论 将硝苯地平制成微乳凝胶，药物的溶解度提高，制剂质量优良。     

青蒿琥酯自微乳对NAFLD大鼠的保护作用及机制研究

目的 探讨青蒿琥酯自微乳对非酒精性脂肪肝（non-alcoholic fatty liver disease,NAFLD）模型大鼠的保护作用及作用机制。方法 高脂饲料诱导10周建立大鼠NAFLD模型。SD大鼠分为7组：正常组,模型组,青蒿琥酯组,多烯磷脂酰胆碱组,青蒿琥酯自微乳高、中、低剂量组。给药10周后处死所有动物,检测各组大鼠血清ALT、AST、TG、TC、TNF-α和IL-10指标水平。结果 与模型组比较,各药物治疗组（除低剂量组外）均能明显改善血清ALT、AST、TG、TC、TNF-α和IL-10指标水平（P<0.05或<0.01）。结论 青蒿琥酯自微乳通过调节脂质代谢、抑制炎性细胞因子的释放,减轻肝细胞的损伤,从而对高脂饮食诱导的NAFLD模型大鼠具有一定的保护作用。     

青蒿琥酯自微乳在大鼠体内的药动学研究

目的 建立大鼠血浆中青蒿琥酯的HPLC-MS/MS测定方法,并研究青蒿琥酯自微乳在大鼠体内的药动学特征。方法 12只SD大鼠随机分为2组,单剂量分别灌胃（50 mg·kg^-1）青蒿琥酯自微乳和青蒿琥酯原料药,以格列吡嗪为内标,用LC-MS/MS测定给药后血浆中的药物浓度,并计算药动学参数。结果 青蒿琥酯血浆样品的线性范围为1.0~1 000.0 ng·mL^-1,回归方程为A=294.74C-439.33（r=0.999 6）,定量下限为1.0 ng·mL^-1。日内、日间变异系数（RSD）均<10%,符合生物样品的分析要求。青蒿琥酯原料药和青蒿琥酯自微乳的药动学参数C_max、t_1/2和AUC_0→t分别为：（87.6±8.80）ng·mL^-1,（1.88±0.33）h和（43.3±1.74）h·ng·mL^-1;（421±41.6）ng·mL^-1,（1.48±0.17）h和（282±17.7）h·ng·mL^-1。其中,C_max和AUC_0→t存在显著性差异（p<0.01）。结论 该方法简便灵敏,可用于血浆中青蒿琥酯的含量测定,经灌胃给药后,与原料药比较,青蒿琥酯自微乳能显著提高生物利用度。     

丹酚酸B-丹参酮ⅡA-甘草次酸微乳凝胶微针透皮给药的评价

目的 优化丹酚酸B （SalB）-丹参酮Ⅱ_A（TSNⅡ_A）-甘草次酸（GA）（STG）微乳凝胶的处方工艺,并考察微针给药对其促透和抗炎药效的影响。方法 以微乳凝胶的综合评分为响应值,选取卡波姆用量、微乳用量、pH值作为考察因素,通过Box-Behnken响应面法筛选最佳处方工艺。采用透皮扩散试验仪考察STG微乳凝胶、STG微乳凝胶+微针（长度分别为500、750、1 000μm）给药的体外经皮渗透特性,高效液相色谱（HPLC）测定TSNⅡ_A、Sal B和GA的含量。采用10%蛋清诱导小鼠足肿胀考察STG微乳凝胶（每次l g,每天2次,给药3 d）、STG微乳凝胶+微针（长度分别为500、750、1000μm）背部给药的抗炎作用,同时考察给药7d对小鼠皮脂腺斑组织的作用。结果 STG微乳凝胶的最佳制备工艺中卡波姆用量为1.00%、微乳用量为0.10 g、pH值为6,制备的STG微乳凝胶中含TSNⅡ_A、SalB、GA分别为0.18、1.05、1.53 mg·g^-1。与TSNⅡ_A比较,SalB和GA的透皮吸收较好;STG微乳凝胶经过与不同长度微针配合使用后的累积透皮量：STG微乳凝胶+1 000μm微针组>STG微乳凝胶+700μm微针组>STG微乳凝胶+500μm微针组>STG微乳凝胶组;3种药物在皮肤中的滞留量相对较高。与空白凝胶组比较,STG微乳凝胶组小鼠足肿胀度有所减轻,但无显著性差异;与STG微乳凝胶组比较,STG微乳凝胶+微针组小鼠足肿胀程度均明显减轻,以1 000μm微针组作用最显著（P<0.05、0.01）。小鼠皮脂腺斑组织HE染色结果表明,与空白凝胶组比较,各组小鼠皮脂腺数目减少且体积变小,以微针长度1 000μm组效果最显著。结论 STG微乳凝胶+微针给药具有良好的透皮特性和缓释效果,发挥抗炎及控制皮脂腺分泌作用,微针长度与透皮率的增加呈正相关。     

保乳治疗乳腺癌患者临床病理特征与预后的相关性

目的 分析行保乳治疗的乳腺癌患者临床、病理特征与预后的相关性。方法 回顾性分析2010年1月至2012年12月于安徽医科大学第二附属医院接受保乳治疗的206例女性乳腺癌患者临床资料,总结患者的临床、病理特征。通过Kaplan-Meier单因素分析患者临床、病理特征（年龄、月经状态、病理类型、肿瘤大小、淋巴结状态、激素受体状况、Ki-67指数、HER-2表达状况、神经脉管浸润情况等因素）对预后的影响,对单因素分析差异有统计学意义的因素进行Cox回归分析。结果 单因素分析显示,不同年龄患者5年生存率比较,差异无统计学意义（P>0.05）,不同月经状态、淋巴结状态、Ki-67指数及神经脉管浸润差异有统计学意义（P<0.05）;多因素分析显示,月经状态、淋巴结状态及Ki-67指数与保乳治疗的预后具有相关性（P<0.05）。结论 保乳治疗的乳腺癌患者的年龄与预后无相关性。绝经、淋巴结转移、Ki-67指数是影响保乳治疗的乳腺癌患者预后独立影响因素。     

基于D-最优混料设计法的塞来昔布微乳凝胶处方优化与评价

目的 制备塞来昔布微乳凝胶，并考察其体外透皮性能。方法 测定塞来昔布在不同油、乳化剂、助乳化剂中的溶解度，通过绘制伪三元相图确定塞来昔布微乳的处方组成；以油相、混合乳化剂、水为考察因素，微乳的载药量和粒径为评价指标，利用D-最优混料设计法优化塞来昔布微乳的处方；以卡波姆980为基质制备塞来昔布微乳凝胶，并测定粒径、粒度分布、Zeta电位、透光率及黏度，透射电镜观察塞来昔布微乳的外观形态；采用Franz扩散池法考察塞来昔布微乳凝胶的体外释放性能。结果 优化的塞来昔布微乳处方组成为油相4%、混合乳化剂20%、水76%；塞来昔布微乳凝胶的平均粒径为（59.65±1.09）nm，PDI为0.106，Zeta电位为（-25.76±0.92）mV；透射电镜观察微乳凝胶呈圆整、规则球形，分布较为均匀；与微乳相比，塞来昔布微乳凝胶黏度增大，便于涂布和经皮给药；塞来昔布微乳凝胶24 h累积透皮释放量为（80.12±3.37）μg·cm^-2，显著高于塞来昔布混悬液。结论 塞来昔布微乳凝胶可以显著增加药物的累积透皮量，有望成为新型局部给药制剂。     

真菌Chaetomium sp.的次级代谢产物研究

目的 对海洋毛壳属真菌Chaetomium sp.的次级代谢产物进行研究。方法 运用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、HPLC等现代色谱方法对Chaetomium sp.的发酵产物进行分离纯化,利用现代波谱技术结合文献报道进行结构鉴定。结果 共分离得到4个十元环内酯化合物,botryolides A、botryolides B、botryolides D和decarestrictine I,1个倍半萜类化合物trichothecolone。结论 本研究是对海洋真菌Chaetomium sp.次级代谢产物的首次报道,5种化合物均为首次从该种真菌中分离得到。     

硝苯地平自微乳的性能研究

目的 将硝苯地平制备成微乳,以提高其生物利用度。方法 利用透射电镜以及Zeta电位测定仪等技术检测硝苯地平自微乳的平均粒径及粒径分布、形态特征、表面电位、稳定性、药物的体外释放以及体内的吸收等特点,并进行初步质量评价研究。结果 所制得的硝苯地平自微乳平均粒径为25~26 nm,分布较为集中;粒子形态圆整,大小均匀;表面电位为-（25.1±1.1） mV;体外释放度>90%。结论 将硝苯地平制成自微乳,药物在体内有良好的吸收。     

Comparison of CZE, MEKC, MEEKC and non-aqueous capillary electrophoresis for the determination of impurities in bromazepam

The purpose of the present investigation was to develop a test for related substances in the benzodiazepine drug substance bromazepam based on capillary electrophoresis (CE). A final method for the determination of impurities in bromazepam is based on non-aqueous capillary electrophoresis (NACE). Five modes of capillary electrophoresis were investigated and compared for the said purpose. All the CE systems investigated make use of running buffers at low pH in order to protonate the analytes. A low pH of the running buffers was needed as the pK(a) values of benzodiazepines in general are in the range from 1.3 to 4.6. Dynamically coated capillaries were used to overcome the low electro-osmotic flow at low pH in the aqueous buffers investigated. CZE with and without dynamical coating of the internal surface of the fused capillaries was compared and also micellar electrokinetic chromatography (MEKC) as well as microemulsion electrokinetic chromatography (MEEKC) performed in dynamically coated capillaries were investigated. The NACE was chosen as the best technique as the low solubility of the benzodiazepines in water is easily overcome. The NACE system showed good selectivity and detectability for the substances investigated and the limit of quantitation for the impurities corresponded to 0.05% of the drug substance. Linearity was good.     

Simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and Chinese medicinal preparations by microemulsion electrokinetic chromatography

The present paper describes the development of a microemulsion electrokinetic chromatographic (MEEKC) method for simultaneous determination of andrographolide and dehydroandrographolide in traditional Chinese medicines and Chinese medicinal preparations. The MEEKC method involved the use of sodium dodecyl sulfate (SDS) as surfactant, heptane as organic solvent and butan-1-ol as co-solvent. The effect of temperature and pH of running buffers on separation were examined. The optimized conditions (heptane 0.81% (w/w), SDS 3.31% (w/w), butan-1-ol 6.61% (w/w) and 10mM sodium tetraborate buffer, pH 9.2) allowed a useful and good reproducible separation of the studied analytes to be achieved.     

A novel double coating for microemulsion electrokinetic chromatography with laser-induced fluorescence detection: as tested with amino acid derivatives

A novel double coating (DC) was developed for fast and reproducible microemulsion electrokinetic chromatography (MEEKC), as tested with separation and determination of amino acids using laser-induced fluorescence (LIF) detection after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazol. The simple coating is a combination of a removable covalent layer and a dynamic SDS coating. Hexamethyldisilazane was utilized for the covalent layer that can be regenerated on-line. Compared with previous no-coating method, the analysis time was shortened; and the reproducibility of migration times was improved.     

Development and validation of a microemulsion electrokinetic chromatography method for patulin quantification in commercial apple juice

A microemulsion electrokinetic chromatography (MEECK) method for patulin (PAT) quantification in apple juice samples has been developed. The effects of several important factors such as co-surfactant type, concentration of surfactant, acetonitrile percentage in the microemulsion, and running voltage and temperature were investigated to determine the optimum conditions. They resulted to be: a background electrolyte (BGE) composed of 25 mM of sodium tetraborate, SDS (2.16% w/w), ethanol (6.49% w/w), n-octanol (0.82% w/w) and 2% v/v acetonitrile; applied voltage of +15 kV; and a capillary temperature of 35 °C. PAT was detected at 276 nm. Quantification and detection limits (LOQ and LOD) in apple juice samples were 8.0 μg L⁻¹ and 3.2 μg L⁻¹, respectively. Patulin was extracted from apple juice using ethyl acetate with a mean recovery value of 75.3% (RSD = 4.5).

This method was applied to the measurement of patulin in twenty commercial apple juice samples obtained from different Danish supermarkets. The PAT apple juice mean and median levels obtained were 35.9 and 10.9 μg L⁻¹, respectively.

The comparison with a previously validated micellar electrokinetic chromatography (MEKC) method for PAT analysis showed the suitability of using MEEKC for this mycotoxin analysis. However, the expectations of obtaining a higher efficiency and thus lower limits of detection and quantitation when using MEEKC were not met.     

Analysis of rhubarb anthraquinones and bianthrones by microemulsion electrokinetic chromatography

In this work a method of microemulsion electrokinetic chromatography (MEEKC) has been developed for the analysis of nine anthraquinones and bianthrones in rhubarb. This study employed di-n-butyl tartrate as oil substance to make up the microemulsion. The composition of the microemulsion was 0.5% (w/w) di-n-butyl tartrate, 0.6% (w/w) SDS, 1.2% (w/w) 1-butanol and 97.7% (w/w) 10 mM sodium borate buffer, pH of the buffer being 9.2. Acetonitrile was added to the emulsion to improve the separation. The volume ratio between the emulsion solution and acetonitrile of an optimized separation was 70:30. With the optimized conditions all of the nine analytes were baseline-separated in peaks of good shapes within 20 min. After validation the method was used to analyze the components in a rhubarb sample. A solid-phase extraction procedure was employed. Five anthraquinones and two bianthrones had been detected in the sample and their amounts were determined. The method should be able to be used for the quantitative analysis of the main active components of rhubarb crude drugs.     

Impurity profiling of atropine sulfate by microemulsion electrokinetic chromatography

An oil-in-water microemulsion electrokinetic chromatography (MEEKC) method has been developed and validated for the determination of atropine, its major degradation products (tropic acid, apoatropine and atropic acid) and related substances from plants material (noratropine, 6-hydroxyhyoscyamine, 7-hydroxyhyoscyamine, hyoscine and littorine). Separation of atropine and all impurities was optimized by varying the voltage, the nature of the oil droplet and the buffer, as well as the organic modifier (methanol, 2-propanol or acetonitrile) and the surfactant type and concentration. The optimum O/W microemulsion background electrolyte (BGE) solution consists of 0.8% (w/w) octane, 6.62% (w/w) 1-butanol, 2.0% (w/w) 2-propanol, 4.44% (w/w) SDS and 86.14% (w/w) 10 mM sodium tetraborate buffer pH 9.2. In order to shorten the analysis time a voltage gradient was applied. The validation was performed with respect to specificity, linearity, range, limit of quantification and detection, precision, accuracy and robustness. The established method allowed the detection and determination of atropine sulfate related substances at impurity levels given in the European Pharmacopoeia. Good agreement was obtained between the established MEEKC method and the traditional RP-HPLC method.     

Separation and on-line preconcentration by stacking and sweeping of charged analytes in the plant by microemulsion electrokinetic chromatography with nonionic surfactants

A novel on-line technique for stacking and sweeping of long sample plugs with simultaneous determination of charged analytes in the plant (protocatechuic aldehyde, rosmarinic acid, danshensu, salvianolic acid B, and protocatechuic acid) by the nonionic microemulsion electrokinetic chromatography (MEEKC) is presented. The preconcentration efficiency provided about 9–28-fold for stacking and 7–14-fold for sweeping in the enhancements of LOD. The effects of oil phase, Brij-35 and buffer concentrations on stacking and sweeping efficiency were examined in order to optimize the two methods. In nonionic MEEKC, the effect of the type of oil and buffer contents on preconcentration mechanism is often sophisticated. This study had demonstrated that the oil type and buffer content in nonionic microemulsion indeed markedly altered the affinity of microemulsion with analytes. Finally, in comparison to the stacking method, the most apparent disadvantages of the sweeping method were the relatively high limits of detection and poor peak shapes.     

Characterization of Interactions Between Bile Salts and Drugs by Micellar Electrokinetic Capillary Chromatography. Part I.

Purpose. The general properties of micellar electrokinetic capillary chromatography (MECC) were utilized to characterize the strength of interactions between bile salts and biological active substances. Methods. For that purpose various bile salts were used as micellar pseudostationary phase in the background electrolyte. Furthermore, a physicochemical model was applied and the effective partition coefficients between micellar and water phase were calculated in order to evaluate the strength of interactions between bile acids and the drugs. Results. It was found that the interactions between the selected drugs and bile salts depend both on the lipohilicity of the drugs and on the charge of the components. Only hydrophobic, cationic drugs such as quinine and propranolol are able to interact with these surface-active agents. Conclusions. MECC is a valuable methode to characterize interactions such occurring between drugs and bile salts.