紫杉醇纳米胶束冻干粉针剂的药效评价

目的对紫杉醇／聚乙二醇一聚谷氨酸苄酯（PEG—PBLG）纳米胶束冻干粉针剂的抗肿瘤药效学进行考察。方法采用MTT比色法、荷瘤裸鼠模型,对紫杉醇／PEG—PBLG纳米胶束冻干粉针剂在体内外的抗肿瘤效果进行研究,并与市售紫杉醇聚氧乙烯蓖麻油注射液进行比较。结果当紫杉醇浓度≤10μg／ml时,紫杉醇／PEG—PBLG冻干粉针剂对体外HepG-2肝癌细胞的毒性低于相应浓度的市售紫杉醇注射剂（P〈0．01）;而冻干粉针剂在移植瘤的肝癌裸鼠模型中,具有与市售紫杉醇注射剂相当的抑制肿瘤疗效（P〉0．05）。结论紫杉醇／PEG—PBLG冻干粉针剂具有与市售紫杉醇注射液相当的抗肿瘤作用,并且细胞毒性降低,有较为广阔的临床应用前景。     

紫杉醇自组装核壳型纳米胶束的制备与性能

本文合成了聚乙二醇-聚谷氨酸苄酯(polyethylene glycol-polybenzyl-L-glutamate， PEG-PBLG)两亲嵌段共聚物， 并采用超微透析法制备了紫杉醇/PEG-PBLG核壳型纳米胶束。通过高效液相色谱测定了胶束的载药量及药物包封率； 采用动态光散射法测定了胶束的粒径及分布； 通过体外试验研究了紫杉醇/PEG-PBLG胶束的释药特性； 采用四噻唑蓝法考察了紫杉醇/PEG-PBLG胶束的体外细胞毒性； 通过裸鼠的抑瘤试验评价了紫杉醇胶束对人肝癌细胞的疗效。结果表明， PEG-PBLG胶束能包埋疏水性药物紫杉醇； 紫杉醇/PEG-PBLG胶束的粒径为80～265 nm， 且随着载体共聚物PBLG嵌段相对分子质量的升高而增大； 紫杉醇/PEG-PBLG胶束的体外释放具有缓释特性； 当紫杉醇浓度大于20 μg·mL^-1时， 紫杉醇/PEG-PBLG胶束的细胞毒性低于相应浓度的紫杉醇/聚氧乙烯蓖麻油注射剂(P<0.05)， 紫杉醇/PEG-PBLG胶束具有与紫杉醇/聚氧乙烯蓖麻油注射剂相似的抑制肿瘤作用。综上所述， 紫杉醇/PEG-PBLG纳米胶束具有较均匀的粒径及粒径分布、 缓释特性、 低毒和较好的抗肿瘤作用。     

几种药用高分子辅料的体内外毒性比较

目的：通过细胞与动物实验,比较聚乙二醇1000维生素E琥珀酸酯（ TPGS1000）、普朗尼克（ F127）、单甲氧基聚乙二醇外消旋聚乳酸两嵌段共聚物（mPEG－PLA）及其三嵌段共聚物（PLA－PEG－PLA）、外消旋聚乳酸乙醇酸三嵌段共聚物（PLGA－PEG－PLGA）5种常用药用高分子辅料的体内外毒性,为选择安全有效的药用辅料提供实验依据。方法采用CCK－8法检测以上5种常用高分子药用辅料对人脐静脉内皮细胞 HU－VEC和人肝癌细胞Bel－7402的毒性;采用动物毒性试验方法初步观察5种辅料对小鼠的毒性反应。结果 TPGS在5种辅料中对细胞的毒性作用较强,其余4种辅料在1mg? mL －1几无毒性表现,仅在5mg? mL －1剂量下才表现出低毒。体内毒性实验中,TPGS的LD50约为500mg? kg －1,其他辅料在各剂量组小鼠均未出现明显毒性现象或死亡。结论体内外毒性试验结果提示：药用高分子辅料具有一定的毒性作用,将TPGS用作药用高分子辅料时,需特别考虑其用量,以确保新剂型的安全性;其他4种辅料在相同剂量下未表现出明显毒性,是比较安全的药用辅料。     

紫杉醇嵌段共聚物纳米粒的制备及体外实验研究

目的：制备紫杉醇嵌段共聚物纳米制剂，研究其理化性质和体外抗癌活性。方法：采用界面沉积法制备了负载紫杉醇的聚乙二醇单甲醚-乳酸羟基醋酸共聚物（mPEG-PLGA）嵌段共聚物纳米粒，运用粒径分析仪测其粒径及Zeta电位，透射电镜表征纳米粒的形态，研究了投药量及mPEG在共聚物中的不同含量对纳米粒的影响，考察所制纳米粒对癌细胞的作用。结果：所制纳米粒为球形．粒径为纳米级，与临床用的紫杉醇注射液相比，癌细胞的存活率明显降低，且对癌细胞作用时间越长，细胞毒性作用越明显。结论：该试验可为开发紫杉醇新型静脉注射制剂提供了实验依据。     

蓝萼甲素自组装纳米胶束的制备与性质研究

摘要目的制备蓝萼甲素自组装纳米胶束,并考察其性质。方法以三嵌段聚合物聚酯 聚乙二醇（PLGA PEG PLGA）为载体,采用溶剂蒸发法制备蓝萼甲素胶束,并通过正交实验筛选最佳制备工艺;采用芘荧光探针法测定临界胶束浓度（CMC）,透析法测载药胶束包封率和载药量,Zetasizer nano ZS仪测定其粒径和Zeta电位,透射电镜观察形态,并对其体外释放进行研究。结果胶束的CMC为2.5×10－3 mg&#8226;mL－1;平均粒径（62.49±0.60）nm,电位为（－25.4±0.4） mV;平均包封率（84.85±2.00）%;平均载药量（5.36±1.00）%;体外缓释约12 h,符合Higuchi方程。结论用三嵌段聚合物PLGA PEG PLGA可制备蓝萼甲素纳米胶束,因其缓释和纳米粒度特性而具有良好的应用前景。     

阿霉素共聚物胶束的制备及体外性质研究

目的制备阿霉素共聚物胶束并研究其体外性质。方法采用开环聚合法合成聚乙二醇单甲醚-聚乳酸羟基乙酸（mPEG—PLGA）嵌段共聚物;用透析法、溶剂蒸发法制备空白及载阿霉素胶束;动态光散射仪（DLS）测定其粒径分布;采用紫外分光光度法测定胶束的包封率和载药量。通过体外释药实验研究了载阿霉素胶束的释药特性。结果采用透析法制备载阿霉素胶束大小均匀,平均粒径为（91．1±15．8）nm;药物胶束的包封率为85．2％,载药量为10．4％;与市售阿霉素注射剂相比,载阿霉素胶束具有良好的缓释性能。结论共聚物胶束可作为疏水性药物阿霉素的载体。     

聚乙二醇／聚对苯二甲酸丁二醇酯的体外降解行为及生物相容性研究

以聚乙二醇／聚对苯二甲酸丁二醇醑(PEG／PBT)嵌段共聚物为原料，进行了共聚物在37℃、pH7．4条件下的体外降解行为及失重率的测定。并在(PEG／PBT)支架材料上进行细胞培养。结果表明(PEG／PBT)聚合物是一种具有良好生物相容性的可降解性的高分子材料。     

紫杉醇PLA-PEG嵌段共聚物纳米粒腹腔注射的组织分布

分别以嵌段（聚乳酸-聚乙二醇）和非嵌段（聚乳酸）共聚物作为载体材料，采用乳化-液中干燥法制备包载紫杉醇的纳米粒。再以市售注射剂为对照，考察大鼠单剂量腹腔注射7．5mg／kg后，心、肝、脾、肺、肾、髂淋巴结等组织的药物分布情况。以相对摄取率Re、峰浓度比ce和靶向效率Te为指标评价制品的淋巴靶向性。结果表明，两亲性嵌段共聚物纳米粒可明显增强药物淋巴靶向性，并显著减少肝、脾等组织的分布。     

可注射更昔洛韦温敏型原位凝胶剂的研究

构建温敏型三嵌段共聚物,研究其理化性质以及用其制备的可注射更昔洛韦温敏型原位凝胶剂的制剂特性。以聚乙二醇（PEG）作为亲水嵌段．丙交酯（LA）和β-丁内酯（β-BL）的无规共聚物PBLA作为疏水嵌段．采用开环聚合法合成温敏型三嵌段共聚物PBLA-PEG-PBLA,并对其理化性质进行表征,考察其溶液的胶凝温度／临界凝胶浓度、流变学性质、通针性和溶蚀行为以及以更昔洛韦作为模型药物、用其制得的可注射载药温敏型原位凝胶剂的体外释放特性。合成的PBLA-PEG-PBLA嵌段共聚物重均分子质量在6000左右,多分散系数为1．5左右;其溶液临界凝胶浓度（g·mL^-1）为5％-10％,质量浓度（g·mL^-1）在10％～25％时胶凝温度为31～35℃,接近并略低于体温：其凝胶在低温下储能模量与黏度较小,当温度接近相转变温度后两者迅速增大：其载药凝胶剂累计释放量经拟合显示遵循一级动力学方程,并呈扩散释药机制。较低质量浓度[10％15％（g·mL^-1）的PBLA—PEG—PBLA更符合玻璃体注射要求,更适用于制备可注射载药温敏型原位凝胶剂。     

藤茶双氢杨梅树皮素对2215细胞分泌HBsAg及HBeAg的抑制作用

目的研究藤茶双氢杨梅树皮素（DHM）在2215细胞培养中对乙型肝炎病毒分泌HBsAg及HBeAg的抑制作用。方法接种2215细胞24h后．加入DHM培养8d，观察DHM对细胞的毒性．在无毒质量浓度下，将药物加入2215细胞培养8d，测定培养液中HBsAg和HBeAg水平。结果DHM半数细胞毒质量浓度（TC50）为272．5ug／mL，最大无毒质量浓度（TCu）为62．5ug／mL；在最大无毒质量浓度下，DHM对2215细胞分泌HBsAg及HBeAg具有明显的抑制作用？对于HBsAg，DHM半数有效量（IC50）为17．7ug／mL，治疗指数（TI）为15．4；对于HBeAg，IC50为21．8ug／mL，TI为12．5。结论DHM对2215细胞分泌HBsAg及HBeAg有明显的抑制作用。     

In vitro cytotoxicity of paclitaxel/beta-cyclodextrin complexes for HIPEC

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a promising strategy in the treatment of peritoneal carcinomatosis. To perform HIPEC, a tensioactive- and solvent-free paclitaxel formulation consisting of water-soluble paclitaxel/randomly methylated-beta-cyclodextrin (Pac/RAMEB) complexes was developed previously. Using MTT and SRB assays the cytotoxic activity of this formulation versus Taxol, was evaluated as well as the cytotoxicity of the different formulation excipients (RAMEB and Cremophor EL. The possible synergistic effect of heat and paclitaxel-based chemotherapy during HIPEC was also evaluated in vitro. The cytotoxicity assays revealed differences in viability between Cremophor EL and RAMEB treated cells of 40 and 50% for the CaCo-2 human and the CC531s rat colon cancer line, respectively, in favour of RAMEB. Despite the higher cytotoxicity of Cremophor EL, Pac/RAMEB complexes and Taxol were equipotent. Using the MTT and SRB assays the average difference in viability between both cell lines was below 10% and IC50 values showed no significant difference. Hyperthermia after drug administration (41 degrees C during 1h) had no effect on cell viability. These results indicated that it was possible to reformulate paclitaxel with a less cytotoxic vehicle while maintaining the cytotoxic activity of the formulation and that there is no synergism between paclitaxel and heat for in vitro cytotoxicity.     

Lyophilized Paclitaxel Magnetoliposomes as a Potential Drug Delivery System for Breast Carcinoma via Parenteral Administration: <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">in Vivo</Emphasis> Studies

No HeadingPurpose. The study reports in vitro and biological evaluation of lyophilized negatively charged paclitaxel magnetic liposomes as a potential carrier for breast carcinoma via parenteral administration.Methods. Paclitaxel in magnetoliposomes were extracted by centrifugation and quantified by high-performance liquid chromatography (HPLC). Biological properties were studied using pharmacokinetics, in vivo distribution and cytotoxicity assays, as well as a mouse model of EMT-6 breast cancer.Methods. Pharmacokinetic studies showed that encapsulation of paclitaxel in magnetoliposomes produced marked difference over the drug in Cremophor EL/ethanol pharmacokinetics, with an increased t_1/2 19.37 h against 4.11 h. For in vivo distribution, paclitaxel concentration of lyophilized magnetoliposomes in the tumor was much higher than that of lyophilized conventional liposomes or Cremophor EL/ethanol, whereas in heart it was much lower than the latter two formulations via s.c. and i.v. administration. Lyophilized paclitaxel magnetic liposomes showed more potency on the therapy of breast cancer than other formulations via s.c. and i.p. administration.Conclusions. The current study demonstrates that paclitaxel magnetoliposomes can effectively be delivered to tumor and exert a significant anticancer activity with fewer side effects in the xenograft model.     

Development and characterization of a novel Cremophor EL free liposome-based paclitaxel (LEP-ETU) formulation.

Taxol is a marketed product for the treatment of ovarian, breast, non-small cell lung cancer and AIDS-related Kaposi's Sarcoma. It is thus far one of the most effective anticancer drugs available on the market. However, paclitaxel is only sparingly soluble in water and therefore, intravenous administration depends on the use of the non-ionic surfactant Cremophor EL (polyethoxylated castor oil) to achieve a clinically relevant concentrated solution. Unfortunately, Cremophor EL increases toxicity and leads to hypersensitivity reactions in certain individuals. We have developed a well characterized novel lyophilized liposome-based paclitaxel (LEP-ETU) formulation that is sterile, stable and easy-to-use. The mean particle size of the liposomes is about 150 nm before and after lyophilization, and the drug entrapment efficiency is greater than 90%. Stability data indicated that the lyophilized LEP-ETU was physically and chemically stable for at least 12 months at 2-8 and 25 degrees C. Moreover, the formulation can be diluted to about 0.25mg/ml without drug precipitation or change in particle size. In vitro drug release study in phosphate-buffered saline (PBS, pH 7.4) showed that less than 6% of the entrapped paclitaxel was released after 120 h, indicating that the drug is highly stable in an entrapped form at physiologic temperature.     

紫杉醇聚氰基丙烯酸正丁酯纳米粒对人卵巢癌细胞的毒性

目的:评价制备紫杉醇聚氰基丙烯酸正丁酯纳米粒(PTX-PBCA-NPs)的原料的生物安全性以及PTX-PBCA-NPs的细胞毒性。方法:采用四噻唑蓝法(MTT法)和检测乳酸脱氢酶(LDH)活性的方法考察空白PBCA-NPs及其聚合的原料、PTX-PBCA-NPs对L-02人正常肝细胞、卵巢癌敏感株(A2780)和卵巢癌耐紫杉醇肿瘤细胞株(A2780/T)的细胞毒性。结果:制备的空白PBCA-NPs只有在大于608 ng·mL-1时,对于L-02细胞具有明显的毒性(P<0.05);在质量浓度304～608 ng·mL-1,空白PBCA-NPs对A2780和A2780/T细胞有明显毒性(P<0.05)。与同一浓度PTX溶液比较,PTX-PBCA-NPs对A2780和A2780/T细胞的毒性作用明显(P<0.05)。结论:空白PBCA-NPs有一定的生物安全性,PTX-PBCA-NPs在对卵巢癌肿瘤细胞有一定的杀伤能力。     

Effect of unpurified Cremophor EL on the solution stability of paclitaxel

Taxol for Injection Concentrate contains a solution of paclitaxel in a 50:50 v/v mixture of Cremophor EL (cleaned):ethanol. Cleaned, rather than unpurified, Cremophor EL is used as a cosolvent because paclitaxel was observed to be less stable in the presence of unpurified Cremophor. In order to understand the cause of this paclitaxel instability, various studies were performed. The results of these studies, coupled with the examination of degradation products, suggested that carboxylate anions present in the unpurified Cremophor catalyze the degradation of paclitaxel by general base catalyzed ethanolysis. Stabilization of Taxol for Injection Concentrate prepared with unpurified Cremophor can be achieved by addition of strong acids, resulting in neutralization of the carboxylate anions. Separately, a quality control test for the cleaning procedure of Cremophor is needed to insure stability of Taxol for Injection Concentrate. A colorimetric indicator test was identified which can distinguish between good and poor quality cleaned Cremophor as it pertains to paclitaxel stability.     

Cremophor EL pharmacokinetics in a phase I study of paclitaxel (Taxol) and carboplatin in non-small cell lung cancer patients

The purpose of our study was to investigate the pharmacokinetics of Cremophor EL following administration of escalating doses of Taxol (paclitaxel dissolved in Cremophor EL/ethanol) to non-small cell lung cancer (NSCLC) patients. Patients with NSCLC stage IIIb or IV without prior chemotherapy treatment were eligible for treatment with paclitaxel and carboplatin in a dose-finding phase I study. The starting dose of paclitaxel was 100 mg/m2 and doses were escalated with steps of 25 mg/m2, which is equal to a starting dose of Cremophor EL of 8.3 ml/m2 with dose increments of 2.1 ml/m2. Carboplatin dosages were 300, 350 or 400 mg/m2. Pharmacokinetic sampling was performed during the first and the second course, and the samples were analyzed using a validated high-performance liquid chromatographic assay. A total of 39 patients were included in this pharmacokinetic part of the study. The doses of paclitaxel were escalated up to 250 mg/m2 (20.8 ml/m2 Cremophor EL). Pharmacokinetic analyses revealed a low elimination-rate of Cremophor EL (CI=37.8-134 ml/h/m2; t 1/2=34.4-61.5 h) and a volume of distribution similar to the volume of the central blood compartment (Vss=4.96-7.85 l). In addition, a dose-independent clearance of Cremophor EL was found indicating linear kinetics. Dose adjustment using the body surface area, however, resulted in a non-linear increase in systemic exposure. The use of body surface area in calculations of Cremophor EL should therefore be re-evaluated.     

A folate receptor-targeted liposomal formulation for paclitaxel

A novel liposomal formulation of paclitaxel targeting the folate receptor (FR) was synthesized and characterized. This formulation was designed to overcome vehicle toxicity associated with the traditional Cremophor EL-based formulation and to provide the added advantages of prolonged systemic circulation time and selective targeting of the FR, which is frequently overexpressed on epithelial cancer cells. The formulation had the composition of dipalmitoyl phosphatidylcholine/dimyristoyl phosphatidylglycerol/monomethoxy-polyethylene glycol (PEG)2000-distearoyl phosphatidylethanolamine/folate-PEG3350-distearoyl phosphatidylethanolamine (DPPC/DMPG/mPEG-DSPE/folate-PEG-DSPE) at molar ratios of (85.5:9.5:4.5:0.5) and a drug-to-lipid molar ratio of 1:33. The liposomes were prepared by polycarbonate membrane extrusion. The mean particle size of the liposomes was 97.1 nm and remained stable for at least 72 h at 4 degrees C. FR-targeted liposomes of the same lipid composition entrapping calcein were shown to be efficiently taken up by KB oral carcinoma cells, which are highly FR+. FR-targeted liposomes containing paclitaxel showed 3.8-fold greater cytotoxicity compared to non-targeted control liposomes in KB cells. Plasma clearance profiles of paclitaxel in the liposomal formulations were then compared to paclitaxel in Cremophor EL formulation. The liposomal formulations showed much longer terminal half-lives (12.33 and 14.23 h for FR-targeted and non-targeted liposomes, respectively) than paclitaxel in Cremophor EL (1.78 h). In conclusion, the paclitaxel formulation described in this study has substantial stability and favorable pharmacokinetic properties. The FR-targeted paclitaxel formulation is potentially useful for treatment of FR+ tumors and warrants further investigation.     

Preparation and evaluation of paclitaxel-containing liposomes

Paclitaxel, an antitumoral drug, is poorly soluble in aqueous media. Therefore, in a commercialised formulation (Taxol), paclitaxel (30 mg active compound) is dissolved in polyethoxylated castor oil (Cremophor EL) and ethanol. After dilution of Taxol in aqueous media paclitaxel tends to precipitate. Several side effects, attributed to the surfactant Cremophor EL, occur, e.g. bronchospasm, hypotension, neuro- and nephrotoxicity, and anaphylactic reactions. To eliminate these side effects, the solubility of paclitaxel was enhanced using liposomes instead of Cremophor EL. The amount of entrapped paclitaxel in crystal-free liposomes was 0.5 mg/ml liposome suspension, i.e. almost 85 times the native solubility. Thus, 30 mg paclitaxel had to be dissolved in 60 ml liposome suspension, of either multi-lamellar vesicles (MLV's) or of small unilamellar vesicles (SUV's) with 5% sucrose as cryoprotector. No precipitation was observed after dilution of the MLV-formulation with (physiological) water or with 5% aqueous dextrose solution, which proves their suitability for administration with perfusions. The chemical stability of paclitaxel in the prepared MLV's stored at 4 degrees C was demonstrated during a period of 5 months. The chemical degradation to conjugated dienes and hydroperoxides, two oxidative degradation products of EPC, was negligible (less than 1%).     

Investigation of the release behavior of DEHP from infusion sets by paclitaxel-loaded polymeric micelles

The current clinical formulation of paclitaxel (Taxol) contains 1:1 blend of Cremophor EL (polyethoxylated castor oil) and dehydrated ethanol. Cremophor EL and dehydrated ethanol are well known to leach di-(2-ethylhexyl) phthalate (DEHP) from polyvinyl chloride (PVC) infusion bags and PVC administration sets. DEHP is a possible hepatotoxin, carcinogen, teratogen and mutagen. Long-term exposure to DEHP may cause health risks. As an alternative formulation for paclitaxel, paclitaxel-loaded polymeric micelles (PLPM), made of monomethoxy poly(ethylene glycol)-block-poly(d,l-lactide) (mPEG-PDLLA) diblock copolymer, has demonstrated clear advantages over Taxol in pharmacokinetics and therapeutic index. Paclitaxel in either PLPM or Taxol formulations, diluted in 0.9% sodium chloride injection, was stable in the PVC infusion bags. The PLPM formulation significantly reduced the amount of DEHP extracted from PVC infusion bags and PVC administration sets. For PLPM diluted in 0.9% sodium chloride injection, the total amount of DEHP delivered over the simulated infusion period was 0.7 mg for 3h and 2.0 mg for 24 h, which was less than 2.9% of the DEHP extracted by Taxol. These results confirmed that there is negligible risk of DEHP exposure from diluted PLPM i.v. infusion using PVC infusion bags and PVC administration sets.