雷公藤甲素的提取工艺

为了从雷公藤叶子获取更多的杀虫活性物质雷公藤甲素,分别用不同含量的甲醇、95％乙醇或水为溶剂进行回流提取、浓缩制得浸膏。为了进一步制得雷公藤甲素含量相对较高的部位,又用不同比例的四氯化碳,石油醚对浸膏预处理,再用氯仿萃取的方法得氯仿部位。结果表明：用70％甲醇回流提取雷公藤叶子,雷公藤甲素提取率最高,可达0．014％。采用四氯化碳洗涤浸膏,再用氯仿萃取的方法,得到的氯仿部位中雷公藤甲素的含量最高,可达1．83％。     

RP-HPLC测定雷公藤药材中雷公藤甲素

采用反相高效液相色谱法-紫外检测器(RP-HPLC-UV)测定雷公藤药材中雷公藤甲素的含量,色谱柱为Kromasil C18柱(150 mm×4.6 mm,5μm),甲醇∶水溶液(45∶55)为流动相进行等度洗脱,流速1.0 mg/min,进样量20μL,紫外检测波长λ=218 nm。结果表明,每个样本分析时间约10 min,雷公藤甲素保留时间约6.103 min,雷公藤甲素与其他成分分离效果良好,标准曲线y=0.206 7x+2.123 9,r=0.993 3(n=5),线性范围0.01~0.1 mg/m L(r=0.993 3),回收率为96.00%~99.03%,RSD≤2%。本方法专属性强,准确可靠,可以用于雷公藤药材中雷公藤甲素的含量测定。     

HPLC法测定雷公藤药材中雷公藤甲素的含量

建立了雷公藤药材中雷公藤甲素的含量测定方法。采用Gemini-C18(250 mm×4.60 mm,5μm)色谱柱;流动相:乙腈-水(25∶75);检测波长218 nm;流速1.0 mL.min-1,柱温为30℃。结果表明:雷公藤甲素在5.82～58.20μg.mL-1浓度范围内与峰面积呈良好的线性关系(r=0.9996),平均回收率为101.49%,RSD=2.02%。本方法简便、准确、重现性好,可用于雷公藤药材中雷公藤甲素的含量测定。     

HPLC法测定海棠合剂中雷公藤甲素的含量

目的:建立HPLC测定海棠合剂中雷公藤甲素含量测定方法。方法:采用HPLC法,色谱柱为Diamonsil C18柱(250mm×4.6mm,5μm)柱;以乙腈(A)-水(B)为流动相,梯度洗脱(0~20分钟,20%A→50%A;20~21分钟,50%A→20%A),流速为1.0m L/min,柱温35℃,UV检测波长为220nm。结果:雷公藤甲素在进样量在0.02096~0.2096μg范围内与峰面积呈很好的线性关系,回归方程和相关系数:回归方程为A=1586.937C+2.495342,r=0.9999;平均回收率为93.5%,RSD=2.95%(n=6)。结论:该方法灵敏快速,操作简便,重现性好,可用于海棠合剂的质量控制。     

加压溶剂法提取雷公藤甲素及其条件优化

以雷公藤为原料,采用加压溶剂法提取雷公藤甲素,以1,2-二氯乙烷为溶剂,考察了提取时间、料液比和提取温度等因素对提取工艺的影响,并在单因素试验基础上,根据中心组合试验设计原理采用三因素三水平的响应面分析法进行工艺优化,得到提取过程优化的工艺条件为:料液比1:9.7,提取温度115℃,提取时间80min,雷公藤甲素的实际得率可达0.173‰,纯度为1.21%,与常规回流提取法相比优势明显。     

雷公藤甲素脂质体粉雾剂的处方工艺筛选与评价

为降低雷公藤甲素的毒副作用,制备雷公藤甲素脂质体粉雾剂(TP-LD),并进行初步评价。方法采用乙醇注入法和冷冻干燥法制备雷公藤甲素脂质体粉雾剂,并对其进行处方工艺的研究和制剂学评价。结果 雷公藤甲素脂质体包封率为(74.6±1.7)%,粒径大小为(113.03±2.4) nm; Zeta电位为(-43.60±1.2) mv;冻干复溶后TP-LD的粒径大小为(1.17±0.047)μm,流动性与亲水性均较好,满足粉雾剂给药的基本要求。结论 成功制备雷公藤甲素脂质体粉雾剂,工艺简单可行、质量稳定。     

UHPLC法测定不同产地雷公藤饮片中雷公藤甲素和红素的含量

对市售不同产地的雷公藤饮片中雷公藤甲素和雷公藤红素进行含量测定。采用超高液相色谱法。色谱柱为Waters Acquity UPLC BEH C_(18)柱(2.1 mm×100 nm,1.7μm),流动相为乙腈-0.1%磷酸水,梯度洗脱,流速为0.5 mL/min,柱温25℃,检测波长210 nm;两种有效成分在各自的线性范围内线性关系良好,该实验所建立的方法简便,重复性好。不同产地雷公藤饮片中雷公藤甲素和雷公藤红素的含量有显著差异,表明市售雷公藤饮片的质量存在明显差别,为雷公藤饮片进一步的临床应用提供参考。     

白藜芦醇柔性纳米脂质体的制备与表征

制备包裹白藜芦醇的柔性纳米脂质体,并优化配方,得到一个稳定性好、负载量高的体系。实验采用注入法制备柔性纳米脂质体;制备出的柔性纳米脂质体采用光子相关光谱(PCS)和激光衍射(LD)测得粒径为250nm～300nm,PDI为0.1～0.2;透射电镜观察出的脂质体形貌呈球形或椭球形;用高效液相色谱测出白藜芦醇的含量为0.7%～1.1%,采用超滤离心法测得的包封率为99.7%。体系于4℃、25℃以及40℃下分别保存2个月,粒径无明显变化。采用注入法制备柔性纳米脂质体,操作简便,制备出的脂质体性状稳定。     

雷公藤甲素普通脂质体与包合物脂质体体外释药特点对比分析

分别制备雷公藤甲素普通脂质体、β-环糊精(β-CD)包合物脂质体和羟丙基-β-环糊精(HP-β-CD)包合物脂质体,采用透析法进行体外释药实验并绘制释药曲线,对比分析3种脂质体在不同释放介质中的释药特点。研究发现,不同释放介质会对3种雷公藤甲素脂质体的体外释药曲线具有不同程度的影响,影响最大的是β-CD包合物脂质体、其次是普通脂质体,影响最小的是HP-β-CD包合物脂质体。在与人体体液更为接近的磷酸盐缓冲溶液(PBS)中,与普通脂质体相比,β-CD包合物脂质体具有明显的持续缓释作用,其累积释药率为60.0%;而HP-β-CD包合物脂质体释药初期具有缓释作用,中期释药加速,后期又趋缓,其累积释药率为90.0%,释药最为充分。     

酮洛芬醇质体的制备、表征及其体外经皮渗透研究

制备酮洛芬醇质体并考察醇质体作为酮洛芬经皮给药载体的体外透皮特性。采用乙醇注入法制备酮洛芬醇质体,对其从粒径分布、Zeta电位值、包封率方面进行表征;用小鼠皮肤进行体外透皮试验,比较酮洛芬在乙醇溶液、脂质体以及醇质体中的透皮行为。结果表明,制得的酮洛芬醇质体平均粒径为166.0 nm,Zeta电位值为-56.70 m V,包封率为67.87%,12 h后皮肤累计渗透量显著高于酮洛芬脂质体和水溶液。因此,酮洛芬醇质体具有更好的透皮效果,值得进一步研究。     

酮洛芬醇质体的制备、表征及其体外经皮渗透研究

制备酮洛芬醇质体并考察醇质体作为酮洛芬经皮给药载体的体外透皮特性。采用乙醇注入法制备酮洛芬醇质体,对其从粒径分布、Zeta电位值、包封率方面进行表征;用小鼠皮肤进行体外透皮试验,比较酮洛芬在乙醇溶液、脂质体以及醇质体中的透皮行为。结果表明,制得的酮洛芬醇质体平均粒径为166.0 nm,Zeta电位值为-56.70 m V,包封率为67.87%,12 h后皮肤累计渗透量显著高于酮洛芬脂质体和水溶液。因此,酮洛芬醇质体具有更好的透皮效果,值得进一步研究。     

壳聚糖基可注射温敏互穿水凝胶制备及表征

以β-甘油磷酸钠(GP)为羟丙基壳聚糖(HPCS)或壳聚糖季铵盐(HTCC)的温敏交联剂、氯化钙(CaCl_2)为海藻酸钠(SA)的螯合交联剂,采用共混工艺,制备以壳聚糖衍生物-GP为第1网络、海藻酸钙为第2网络的可注射温敏互穿水凝胶。利用高斯软件基于氢键理论探讨凝胶温敏相变机理。利用红外光谱仪、扫描电子显微镜、热重分析仪和流变分析仪对凝胶性能进行了表征。当ρ_(HPCS)=18.75 mg/mL,ρ_(GP)=75 mg/mL,ρ_(SA)=18.33 mg/mL和ρ(CaCl_2)=1.67 mg/mL时,凝胶在37℃温敏凝胶化时间为(85±15)s,压缩弹性模量为(54±15)kPa,损耗模量G″和储能模量G′比值为0.10±0.025。由此可知,HPCS-GP/Ca-Alg复合凝胶可在生理温度环境凝胶化且时间可控,凝胶机械强度良好,在组织工程领域中具有应用潜力。     

Preparation and characterization of thermosensitive beads with macroporous structures

Thermosensitive copolymers of poly(N‐isopropyl acrylamide)‐co‐2‐hydroxyethyl methacrylate (NIPA‐co‐HEMA) macroporous resins were synthesized in the form of beads by inverse suspension polymerization. The copolymerization was carried out in aqueous solutions of the comonomers dispersed by cyclohexane with stabilizers. A series of resins with different molar ratios of NIPA : HEMA, and different crosslinking degrees was obtained. The compositions of the copolymers were determined by elemental analysis. The results showed that the content of HEMA in a copolymer was higher than that of the corresponding feed mixture from which the copolymer was made. IR spectra also confirmed the structure of the copolymers. The porous parameters such as true densities, apparent densities, pore volumes, and porosities of the resins were measured by means of pycnometry. The determination of equilibrium swelling ratios and measurement of differential scanning calibration indicated that the resins exhibited thermosensitivity in aqueous solutions. Finally, the loading of hydroxyl groups was determined by titration. The resins have potential applications as supports in solid‐phase synthesis after being functionalized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1792–1797, 2004     

原位一步法制备温敏改性纳米二氧化硅

采用原位一步法合成了温敏改性聚 N-异丙基丙烯酰胺(PNIPAAm)/SiO2纳米复合物. 通过接触角对温敏改性的纳米SiO2进行了条件优化：反应温度73℃,反应时间6 h,单体用量与KH-570摩尔比为1:1,引发剂用量为单体用量与KH-570总质量的2.5%。通过TEM、FT-IR、XPS等手段对温敏性纳米SiO2的组成和结构进行了表征。同时,这一有机-无机纳米复合物仍然保持PNIPAAm 的温度响应性, 最低临界溶解温度(LCST)与纯PNIPAAm相似。     

Preparation and properties of the novel photoluminescent and thermosensitive hydrogels

Bis[4-(phenyl-isopropyl)phenyl]-4-nitrophenylamine (BiPNPA) (iii) was firstly synthesized via nucleophilic substitution of 4-fluoronitrobenzene (ii) and bis-[4-(phenyl-isopropyl)phenyl]amine (BiPA) (i) in this study, and then compound (iii) was reduced to bis[4-(phenyl-isopropyl)phenyl]-4-aminophenylamine (BiPAmPA) (iv). At last, acrylation of BiPAmPA with acryloyl chloride was performed to obtain a novel bis[4-(phenyl-isopropyl)phenyl]-4-acrylamidophenylamine (BiPAcPA) compound (v). Then, a series of thermosensitive hydrogels were prepared by copolymerization of BiPAcPA and N-isopropyl acrylamide (NIPAAm) by UV irradiation. The effect of BiPAcPA content in the copolymeric hydrogels on the swelling ratio, mechanical properties, and drug release behaviors of the hydrogels was investigated. Results showed that the swelling ratios of the copolymeric hydrogels decreased from 8.2 (g/g) to 5.01 (g/g) when the monomer BiPAcPA content in the copolymeric hydrogel increased from 0.1 mol% to 0.9 mol%. In addition, the thermosensitive behavior obviously decreased with increasing of BiPAcPA content in the hydrogels, but the mechanical properties and crosslinking density of the hydrogel increased with increasing of BiPAcPA content; the caffeine release ratio from 46 % decreased to 29 %. The result of caffeine release also showed that the caffeine-loading amounts decreased with increasing content of BiPAcPA in the hydrogel, but their fractional release increased. In addition, the corresponding copolymers of the copolymeric hydrogels were prepared. Furthermore, the UV absorbance and photoluminescent (PL) behavior of the BiPAcPA, NIPAAm/BiPAcPA copolymeric hydrogels, and their corresponding copolymers in some solvents with different polarities were investigated. The results showed the PL intensity increased with increasing BiPAcPA amounts, especially the wavelength had obvious blue shift phenomenon in THF solvent. The wavelength of UV absorbance and PL emission of BiPAcPA all appeared in visible region. No matter what BiPAcPA monomer, NIPAAm/BiPAcPA hydrogels or NIPAAm/BiPAcPA copolymers, the wavelengths of UV absorbance and PL emission in DMSO solvent are all the same.     

Preparation of chitosan‐based thermosensitive hydrogels for drug delivery

The thermosensitive material that could be transformed into gel at 37°C was prepared from chitosan (dissolved in acetic acid/sodium acetate buffer solution) and a mixture of α‐ and β‐glycerophosphate (αβ‐GP). The thermosensitive characteristics, appearance, and structure of the hydrogel were all affected by the pH, ionic strength, and CS/αβ‐GP ratio. The optimal conditions for the preparation of a transparent CS‐αβ‐GP thermosensitive hydrogel were pH 4.6, ionic strength 0.15 mol/L, and a CS/αβ‐GP ratio of 8.8/1.2 (v/v). The hydrogel was stable for at least 3 months at 4°C. We believe that hydrogen bonding interactions between the N? H (and C?O) groups of chitosan and the O? H groups of αβ‐GP play an important role during the process of sol‐to‐gel transition. The cumulative release of adriamycin from the CS‐αβ‐GP hydrogel, measured in PBS at pH 7.4, reached only 60 to 70% over 24 h, indicating that this material could be potentially used in a sustained drug delivery system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

新型肿瘤热疗用温敏凝胶的制备与表征

采用化学共沉淀结合水热处理的方法,控制一定的反应条件,制备了碳纳米管/四氧化三铁(CNTs/Fe3O4)热种子材料,然后以壳聚糖温敏凝胶为载体,将CNTs/Fe3O4复合材料分散到凝胶中,制备出微波靶向热疗用碳纳米管-四氧化三铁-壳聚糖温敏凝胶。碳纳米管复合热种子材料在凝胶体系中分布均匀,与载体不发生化学反应,25 W下辐照10 min,当CNTs/Fe3O4复合材料的质量浓度为20 mg/mL时,体系温度在初始温度基础上升高了38.7℃,在微波场中具有良好的产热能力,可以满足微波热疗的要求。     

Enhanced transdermal deposition and characterization of quercetin-loaded ethosomes

We sought to evaluate the transdermal permeation potential of quercetin-loaded ethosomes. Quercetinloaded ethosomes were prepared and characterized with regard to particle size, loading efficiency, stability, and in vitro skin permeation. The optimized formulation of ethosomes was confirmed using 2% egg phosphatidylcholine and hydrated 20% ethanol. After quercetin was applied using this formulation, the stability of the ethosomes was determined when loaded with up to 0.04% quercetin. We observed that loading efficiency was improved with increasing concentrations of quercetin. Ethosomes loaded with 0.04% quercetin showed both the greatest loading efficiency (63.9%±6.0%) and an optimal size range (132±32 nm). Ethosomes loaded with quercetin were superior in skin permeation ability (29.5±7.0 μg/cm²) compared to either ethanolic solution or liposomes. Therefore, we concluded that quercetin-loaded ethosomes increased the skin delivery of quercetin. Our results suggest that quercetin-loaded ethosomes may enhance the effect of cosmetic materials.