固定化脂质体色谱研究二至丸及其组成药物的经肠吸收成分

目的:应用固定化脂质体色谱(ILC)分析中药复方二至丸及其组成药物的经肠吸收成分及质量控制。方法:分别观察不同溶剂提取时提取液在ILC色谱柱上的色谱保留与分离,同时对在ILC色谱柱上保留的槲皮素及芹菜素进行了定量分析。结果:从ILC色谱柱保留峰的数目和峰面积两方面观察,墨旱莲的75%乙醇提取优于水提取。二至丸75%乙醇提取液中槲皮素的含量为9.6μg.g-1,芹菜素的含量为2.7μg.g-1。墨旱莲提取液中槲皮素的含量为2.8μg.g-1,芹菜素的含量为3.8μg.g-1。女贞子提取液中槲皮素的含量为9.1μg.g-1,而芹菜素用ILC未检测到。结论:槲皮素和芹菜素是二至丸中主要的可在ILC色谱上保留的成分,其中槲皮素来源于两个组成药物女贞子和墨旱莲,芹菜素仅来源于墨旱莲。槲皮素和芹菜素可能是二至丸的经肠吸收活性成分。固定化脂质体色谱有望成为中药及其复方肠吸收成分的初筛选和定量评价方法之一。

脂质体电动色谱法评价阿魏酸与生物膜的相互作用

利用脂质体与生物膜结构的相似性，将脂质体加入毛细管电泳缓冲溶液中作为假固定相，在数分钟内测定了阿魏酸的脂水分配系数Klw,建立了脂质体电动色谱评价阿魏酸与生物膜相互作用的方法。研究了脂质体中胆固醇的含量、缓冲溶液pH值和缓冲体系对Klw的影响。结果表明，在实验条件范围内（胆固醇含量0～30％，pH值4.0～12．0），胆固醇含量升高，缓冲溶液pH值增大，Klw降低；在不同的缓冲体系中，离子强度越大，Klw越大。脂水分配系数的变化反映了阿魏酸与生物膜相互作用。

脂质体电动色谱预测芳香化合物毒性的研究

采用脂质体电动色谱对芳香化合物急慢性毒性参数、生物蓄积系数进行了预测,并使用统计学方法对定量保留活性关系(QRAR)模型的预测能力、稳定性进行了评价,结果表明,芳香化合物在脂质体电动色谱中的保留值(log k)与各项生态毒性参数之间呈现负线性相关关系,与生物蓄积系数呈现正线性相关关系,F检验结果表明其线性关系在置信度95%下非常显著。交互校验结果表明,该QRAR模型具有良好的稳定性,适于预测非反应性毒性化合物的毒性与生物蓄积系数。

中性芳香族溶质在脂质体电动色谱中的热力学分配行为

脂质体电动色谱是一种理想的评价药物与生物膜相互作用的模型.在288～323K范围内测定了中性芳香族溶质在脂质体电动色谱中的分配系数,通过三项式拟合Van'tHoff图获得了一系列的热力学参数,研究了溶质在脂质体电动色谱中的热力学分配行为.结果表明,分配系数随体系温度的升高和苯环所带亚甲基数目的增加而增大.从288到323K,△H>0,-T△S<0,△G<0,溶质在脂质体电动色谱中的分配过程为熵驱动过程.从288到298K,脂质体电动色谱分配系统的△Cp为负值,其表现行为与经典疏水作用一致.从303到323K,脂质体电动色谱分配系统的△Cp为正值,其表现行为与经典疏水作用不完全吻合.△H和△S呈线性关系,该分配系统存在焓熵补偿.

3种色谱模式联用在中药活性成分初步筛选中的应用

提出了反相高效液相色谱 (RP HPLC)、固定化脂质体色谱 (ILC)以及固定化载体蛋白色谱 (ICPC) 3种色谱模式联用筛选中药中活性成分的新思路 ,并用于传统中药川芎中的生物活性成分的初步筛选。从川芎的甲醇提取液中筛选出几种既有细胞膜的穿透能力又有与载体蛋白的结合能力的成分 ,并对其中两种主要的组分进行了初步的结构鉴定。

磷脂酰胆碱组分的二维液相色谱分离

建立了以脂质体生物色谱-反相高效液相色谱的离线二维色谱分析方法模型,以磷脂酰胆碱(Phosphatidyl choline,PC)为样品进行色谱分析。首先采用PBS(磷酸盐缓冲溶液)为流动相,流速为0.4 m L/min,以固定相脂质体液相色谱柱(Immobilized lliposomes chromatography,ILC)的一维色谱分离。二维色谱分离采用反相C_(18)色谱柱进行分离,流速为1 m L/min。磷脂酰胆碱在固定相脂质体色谱上仅有1个保留峰,但在反相C_(18)色谱柱上却存在着多个保留峰。因此,由脂质体生物色谱-反相高效液相色谱组成的二维分离色谱在阐释了生物色谱意义的同时也充分体现了二维色谱的分离优越性。

脂质体电动色谱与磷脂膜色谱及正辛醇/水系统亲脂性测量尺度的比较研究

目的:对脂质体电动色谱、磷脂膜色谱、正辛醇/水系统的亲脂性测量尺度进行比较研究。方法:采用脂质体电动色谱法测定了20种荷电药物的色谱保留因子,并与磷脂膜色谱保留因子和正辛醇/水系统分配系数(logP)进行线性相关比较。结果:脂质体电动色谱保留因子与磷脂膜保留因子的相关程度(R2=0.55)比其与logP的相关程度(R2=0.25)要高;对于碱性药物,其与脂质体相互作用时,疏水作用力占据主要地位;对于酸性药物,其与脂质体相互作用时,静电排斥力占据了主导作用。结论:脂质体电动色谱、磷脂膜色谱、正辛醇/水系统三者的亲脂性测量尺度明显不同。

生物色谱用于中药活性成分筛选

生物色谱是基于受体药理学、细胞生物学、液相色谱技术等原理,以生物活性材料为固定相配基的新型色谱技术,其特点在于能够反映待测物的生理学及药效学作用。该色谱技术用于中药活性成分筛选具有高通量、特异性较强、分离筛选相结合等优势,并为研究药物与受体相互作用、蛋白质的分离提纯及中药质量控制等提供了新的方法。本文介绍了固定化脂质体色谱、细胞膜色谱、分子生物色谱等在中药活性成分筛选领域中的应用。

Preparation of stealthy etoposide proliposomes and the pharmacokinetics in rabbits

The objectives of the present study were to prepare stealthy etoposide proliposomes and study the pharmacokinetics in rabbits. Blank stealthy liposomes were prepared by film dispersion method. Stealthy etoposide liposomes were prepared by using the ammonium sulfate gradient loading procedure. Vacuum freeze-drying technique was used to dry stealthy etoposide liposomes. Encapsulation efficiency of stealthy etoposide proliposomes was determined by Sephadex chromatography. The morphology was observed by transmission electronic microscope. The particle size and zeta potential were measured by using electrophoretic light scattering technology. The pharmacokinetics in rabbits was evaluated by comparison with etoposide injection and conventional liposomes, respectively. Mean encapsulation efficiency of stealthy etoposide proliposomes was 83.92% ± 3.65% （n = 3）. The liposomes were round or oval. Mean particle size was （124.5 ±26.9） nm, and zeta potential was （-39.50 ±1.04） mV. Following intravenous injection administration at a dose of 1.5 mg/kg etoposide, the three kinds of etoposide preparations were fitted with the two-compartment model. T1/2 β and A UC values of stealthy etoposide proliposomes were （19.26 ± 3.16） h and （26.04 ±3.53） μg/h/mL, respectively. T1/2 β and AUC values of etoposide injection were （0.94 ± 0.21） h and （0.98 ± 0.26） μg/h/mL, respectively. T1/2β and AUC values of conventional liposomes were （7.99 ± 1.36） h and （11.65 ± 1.70） μg/h/mL, respectively. Results indicated that the stealthy etoposide proliposomes could significantly extend the duration of etoposide in blood circulation.

Preparation of anti-resistant stealthy liposomes by incorporating vincristine with quinacrine and the pharmacokinetics in Sprague-Dawley rats

Aim The objectives of the present study were to prepare stealthy vincristine plus quinacrine liposomes and evaluate the pharmacokinetics in Sprague-Dawley rats. Methods Anti-resistant stealthy liposomes were prepared by incorporating vincristine with quinacrine together using the ammonium sulfate gradient loading procedure. For the pharmacokinetic study, Sprague-Dawley rats were divided into two groups： each rat in the Group Ⅰwas administered intravenously via tail vein as stealthy liposomal vincristine plus quinacrine, and the Group Ⅱ similarly given as a mixture solution of free vincristine plus free quinacrine. The concentrations of vincristine and quinacrine in plasma were measured by HPLC with diode array detection and fluorescence detection, respectively. Results The mean particle size of stealthy liposomes was 135.9 ±7.1 nm and the encapsulation efficiencies of stealthy liposomes were 〉 90% for vincristine, and 〉 85% for quinacrine, respectively. Administered as the stealthy vincristine plus quinacrine liposomes, the plasma exposures of both vincristine and quinacrine were significantly extended, and the mean concentrations of both vincristine and quinacrine were significantly higher compared to those given as the mixture solution of free vincristine plus free quinacrine. The Cmax, t1/2, AUC0-24 h values of vincristine for stealthy liposomal group were significantly increased, but the total clearance Cl values decreased, as compared to those of free drug group, respectively. Similarly, the Cmax, t1/2 and AUC0-24 h values of quinacrine for the stealthy liposomal group were significantly increased, but the total clearance C1 values decreased, as compared to those of free quinacrine. Conclusion The anti-resistant stealthy liposomes are successfully prepared by incorporating vincristine with quinacrine, and the liposomes extend significantly the duration in blood circulation and improve evidently the plasma concentrations of both vincristine and quinacrine.

活性整合指纹图谱技术在中药研究中的应用

中药活性整合指纹图谱技术把化学分析与药理活性评价进行了有效地结合,适合于中药活性成分的筛选,可阐释中医药多成分、多靶点的作用特点。近年来活性整合指纹图谱技术在中医药研究中受到高度重视,并得到广泛的应用。简要综述了常见的几种活性整合指纹图谱技术在中药活性成分筛选方面的研究进展,并探讨中药活性整合指纹图谱技术在其发展过程中存在的问题及对策,为其进一步广泛应用提供科学依据。

Preparation of the nanostructured lipid carriers of artemisinin and its pharmacokinetic evaluation

Artemisinin（ART） is a widely used active drug for malaria, including severe and cerebral malaria. However, its therapeutic efficacy is affected by its lower bioavailability. In the present study, nanostructured lipid carriers（NLCs） were proposed as carrier of ART to improve pharmacokinetic properties of the drug. ART-NLC was prepared by high-pressure homogenization based on orthogonal design. The particle size, zeta potential, encapsulation efficiency（EE） and percentage of drug loading（DL） of ART-NLC were（53.06±2.11） nm,（–28.7±3.59） m V, 73.9%±0.5% and 11.23%±0.37%, respectively. ART-NLC showed the sustained release characteristics and scarcely the hemolysis effect on human red blood cells. The pharmacokinetics of ART-NLC for rats after tail intravenous injection（i.v） or intraperitoneal injection（i.p） were investigated by liquid chromatography-tandem mass spectroscopy（LC-MS/MS）. And ART solution was designed as control preparation. For rats of i.v groups, the AUC0–∞（（707.45±145.65） ng·h/m L） of ART-NLC were significantly bigger than that of ART（（368.98±139.58） ng·h/m L）. The MRT（（3.38±0.46） h） of ART-NLC was longer than that of ART（（1.39±0.61） h）. And similar results were observed for rats of i.p groups. The AUC0–∞（（1233.06±235.57） ng·h/m L） and MRT（（4.97±0.69） h） of ART-NLC were both bigger than those of ART, which were（871.17±234.03） ng·h/m L） and（1.75±0.31） h）, respectively. Compared with ART, ART-NLC showed a significant increase in AUC0–∞（P〈0.05） and MRT（P〈0.001） for both i.p and tail i.v administrations.

A HPLC method for the determination of entrapment efficiency of a new 5-FPE liposome formulation

A simple HPLC method was established for the determination of entrapment efficiency of a new 5-FPE liposome formulation. Chromatographic separation was performed on a Kromasil 100 A C18 column （350 mm×4.6 mm, 5 μm）. The mobile phase was consisted of methanol-water （58：42, v/v）. The flow rate of mobile phase was set at 0.8 mL/min. The UV detection wavelength was 271 nm, and the column temperature was 30 ℃. The linear range of 5-FPE was from 0.8-12.8 μg/mL, r = 0.9999. The RSD of intm-day and inter-day precision were less than 2.97%. The average recovery was from 96.8%-104.6% with RSD less than 2.24%. The method was simple, rapid, accurate, and sensitive. It is suitable for the determination of entrapment efficiency of the 5-FPE liposome formulation.

Development of an HPLC-UV method for the simultaneous determination of epirubicin,amlodipine and dequalinium in anti-resistant liposomes

Novel anti-resistant liposomes have been developed to overcome intrinsic resistance in leukemia.Anticancer agent epirubicin and apoptotic inducer amlodipine were encapsulated into the liposome aqueous core,and the surface of the liposome was modified using dequalinium.The objective of the present study was to establish a high performance liquid chromatography （HPLC） method for the determination of epirubicin,amlodipine and dequalinium in the liposomes.Analysis was performed on an ODS column with an isocratic elution at ambient temperature.Mobile phase was consisted of acetonitrile,0.02 M NaH_2PO_4 and triethylamine（34：66：0.3,v/v/v,pH 4.0）.The detection wavelength was set at 240 nm and the flow rate was 1.0 mL/min.The results showed that the calibration curves of epirubicin,amlodipine and dequalinium were linear in the range of（1-50）μg/mL（r^2= 0.9999）, respectively.The mean recoveries of epirubicin,amlodipine,and dequalinium were in the range of 95.86%-97.52%,97.17%-98.92% and 98.04%-101.13%,respectively.The contents of epirubicin,amlodipine and dequalinium in the liposomes were in the range of（564.2-606.1）μg/mL,（641.0-704.0）μg/mL,and（816.0-898.0）μg/mL,respectively.The encapsulation efficiencies of epirubicin and amlodipine were around 90%,and the modification rate of dequalinium was approximate 70μg/μmol lipids.The proposed HPLC method was simple and accurate for the simultaneous determination of epirubicin,amlodipine and dequalinium in newly developed anti-resistant liposomes.

Enantiomers separation using avidin-liposome complex as a chiral selector in capillary electrophoresis

Avidin-liposome complex is a specific chiral selector used to separate the enantiomers of D,L-tryptophan,D,L-phenylthiohydantoin -serine（D,L-PTH-Ser）,D,L-phenylthiohydantoin-threonine（D,L-PTH-Thr） and R,S-pioglitazone hydrochloride in capillary electrochromatography（CEC）.The avidin is immobilized on the phospholipids coated in the capillary.The liposome used for the phospholipid coating contains l,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-（Cap biotinyl）（sodium salt） （Biotinyl-cap-DPPE）（16：0） and different proportions of L-α-phosphatidylserine（PS） in Tris（hydroxymethyl） aminomethane （Tris） buffer at pH 7.4.A good resolution and reproducibility was obtained by coating the capillary with Biotinyl-cap-DPPE/PS （80：20,mol%） followed by immobilization of 1 mg/mL of avidin solution in N-（2-hydroxyethyl） piperazine-N＇-（2-ethanesulfonic acid） （HEPES） buffer at pH 7.4.A comparative study of chiral separation efficiency with different capillary coating methods and preconditioning conditions was conducted.Finally,the electrochromatographic method was successfully used to separate enantiomers of pioglitazone hydrochloride.Therefore,coated CEC will be a promising tool for pharmaceutical enantiomers separation in new drug development.