去氢骆驼蓬碱聚合物胶束的制备工艺优化及体外释放的研究

目的：研究星点设计-响应面法优化去氢骆驼蓬碱N-癸酰-N-三甲基壳聚糖胶束（harmine loaded N-Decanoate-N-trimethyl chitosan micelles,HM-De-TMC-MIC）的处方优化,并考察在不同介质中HM-De-TMC-MIC的体外释放。方法：以薄膜分散法制备HM-De-TMC-MIC;以粒径、多分散系数、包封率和载药量为指标,通过单因素考察和星点设计-响应面法综合考察药物与载体质量比和复水体积对HM-De-TMC-MIC的影响,并遴选其最优处方。在不同pH的释放介质中,分别考察HM-De-TMC-MIC和HM的体外释放。结果：筛优处方药物与载体质量比为3.6∶10,复溶水体积为6 mL;以最优处方制备的HM-De-TMC-MIC粒径为（148.2±5.0）nm,多分散系数为0.198±0.045,包封率（89.80±0.19）%,载药量（22.79±0.05）%,形态圆整。体外释放试验结果表明,HM-De-TMC-MIC的释放曲线遵循Higuchi方程,与HM溶液相比其释放较为缓慢,并呈现pH敏感释药行为。结论：以星点设计-响应面法优化的HM-De-TMC-MIC具有较好包封率和载药量,粒径分布均匀,具有明显的缓释性。     

多西他赛普朗尼克P123胶束的制备

摘 要 目的： 优化以普朗尼克P123为载体材料的多西他赛胶束处方工艺。方法: 采用薄膜水化法制备多西他赛普朗尼克P123胶束。采用星点设计 效应面法优化胶束处方工艺,以包封率作为评价指标,考察投药量、有机溶剂体积、水化体积、水化温度。采用透射电镜观察胶束形态,并测定胶束的粒径和Zeta电位,以透析法进行胶束体外释放特性考察。结果: 以多元线性回归和二次、三次多项式拟合指标与因素之间的数学关系,结果表明三次多项式拟合度较好,制备出的胶束形态圆整,平均粒径和Zeta电位分别为108.3 nm和 3.99 mV,多分散指数为0.265,平均包封率和载药率分别为（97.91%±0.28％）和（3.72%±0.12％）,多西他赛胶束120 h的累积释放率达95.03%,具有一定的缓释能力。结论:采用薄膜水化法制备的多西他赛胶束工艺简单可行,具有较高的包封率,在体外具有较好的缓释效果。     

星点设计-效应面法优化紫杉醇-PluronicP123共聚物胶束处方工艺

目的以星点设计-效应面法优化紫杉醇-Pluronic P123共聚物胶束处方工艺,以期提高难溶性药物紫杉醇在Pluronic P123载体中的包封率和载药量,并对其理化性质进行表征。方法采用薄膜分散法制备紫杉醇-Pluronic P123胶束,以包封率、载药量和胶束溶液药物浓度为考察指标,紫杉醇投药量和水相用量为自变量,采用星点设计-效应面法优化处方,并对模型进行验证,对粒径、体外释放等理化性质进行表征。结果二次多项式非线性回归模型是描述因素与指标关系的最佳模型,根据所优化处方,制得共聚物胶束的包封率约为85.64%,载药量约为1.68%,平均粒径约为(25.2±2.9)nm,zeta电位为(-11.23±2.64)m V。胶束制剂与普通制剂(Taxol注射液)在4 h内的累积释放分别为50.1%和90.5%,前者具有较强的缓释作用。结论通过采用星点设计-效应面优化法确定的处方工艺,可制备具有较高包封率的紫杉醇-Pluronic P123共聚物胶束,所建模型有较好的实用性和预测性。Pluronic P123可有效增溶难溶性药物紫杉醇,并形成具有较强缓释作用的纳米级共聚物胶束制剂,具有应用于肿瘤治疗的潜力。     

阿霉素-五味子乙素pH敏感聚合物胶束的制备与制剂学性质

目的以p H敏感聚合物聚乙二醇-聚乳酸-聚组氨酸[poly(ethyleneglyco1)-poly(D,L-lactide)-poly(L-histidine),m PEG-PLA-PHis]胶束为载体,联合包载抗肿瘤药物阿霉素与多药耐药逆转剂五味子乙素制备聚合物胶束,并对其制剂学性质进行研究。方法采用薄膜分散法制备阿霉素-五味子乙素p H敏感聚合物胶束,以包封率、载药量和稳定性(载药胶束24 h的包封率和载药量变化)为评价指标,采用单因素试验及Box-Behnken效应面法筛选最优处方;应用透射电子显微镜观察载药胶束的外观形态,动态光散射法测定载药胶束的粒径及zeta电位;透析法考察载药胶束在不同p H条件下的释药行为。结果制备的阿霉素-五味子乙素p H敏感聚合物胶束平均粒径为64.73 nm,zeta电位为-8.7 m V。最优处方中阿霉素包封率为95.3%,载药量为8.7%,五味子乙素包封率为76.1%,载药量为3.4%,载药胶束稳定性较好。体外释放结果表明,所制备的阿霉素-五味子乙素p H敏感聚合物胶束在弱酸性条件下,药物释放速率明显加快。结论采用星点设计-效应面法优化处方与制备工艺,所制备的阿霉素-五味子乙素p H敏感聚合物胶束粒径分布均匀,包封率和载药量良好,具有明显的p H响应行为。     

星点设计-效应面法优化羟基喜树碱/mPEG-S-S-C18纳米粒的制备工艺

目的 制备载羟基喜树碱（hydroxycamptothecin,HCPT）还原响应mPEG-S-S-C18纳米粒,采用星点设计-效应面法筛选优化制备工艺。方法 采用乳化-溶剂挥发法制备HCPT/mPEG-S-S-C18纳米粒,应用单因素法考察投药量、水相/油相体积比、超声功率以及超声时间对载药纳米粒包封率和载药量的影响。在此基础上,以包封率和载药量作为评价指标,采用Design-Expert V8.0.6软件进行星点设计,优化载药纳米粒的制备工艺。结果 优化获得的HCPT/mPEG-S-S-C18纳米粒制备工艺投药量为1.0 mg,水相/油相体积比为4.56∶1,超声功率为562.5 W。该工艺制备的载药纳米粒包封率为（58.14±1.04）%,载药量为（3.46±0.22）%,平均粒径为（322.9±9.52） nm,多分散性指数为0.195±0.05,Zeta电位为（-17.5±2.11） mV。结论 乳化-溶剂挥发法适用于制备HCPT/mPEG-S-S-C18纳米粒,星点设计-效应面法可优化获得载药纳米粒的最佳制备工艺,所得的载药纳米粒包封率和载药量较高,所建立的数学模型预测性良好。     

星点设计-效应面法优化PLGA-PEG纳米粒的处方工艺

摘要：目的:采用星点设计-效应面法优化载体基质为PLGA-PEG的siRNA纳米粒的制备工艺。方法:采用复乳法制备载药纳米粒,以二氯甲烷体积、吐温-80的质量分数和复乳的超声时间为试验因素,纳米粒的平均粒径、包封率和突释量为考察指标,根据星点设计原理安排实验和处方工艺优化。结果:成功制备了纳米粒。最佳工艺为二氯甲烷体积13 ml,乳化剂吐温-80的质量分数为3.1%,复乳的超声时间为2.8 min;按优化处方工艺制备的纳米粒的平均粒径（101.5±6.3）nm,包封率（57.6±4.8）%,体外48 h累积释放度高于80%。结论:星点设计-效应面法适用于PLGA-PEG纳米粒的工艺优化,所建立的数学模型预测性良好。     

辛伐他汀泊洛沙姆P123/F127混合胶束的制备及表征

目的：制备并评价辛伐他汀泊洛沙姆P123/F127混合胶束（simvastatin poloxamer P123/F127 mixed micelles,SIM-MM）。方法：采用薄膜水化法制备混合胶束,以包封率、载药量和渗漏率为考察指标,结合单因素和星点设计-效应面法设计,筛选影响考察指标的关键因素并进行优化,并加以验证以确定SIM-MM最佳处方及工艺参数;通过差示扫描量热法（differential scanning calorimetry,DSC）、傅里叶红外光谱法（Fourier transform infrared spectrometer,FTIR spectrometer）验证SIM-MM的形成;采用透射电镜、粒径测定、Zeta电位进行表征。结果：确定SIM-MM的最佳处方为：P123质量分数为63.64%,F127-P123为170 mg,水相体积为7.5 mL;透射电镜证明SIM-MM为圆球形,DSC和FTIR实验验证胶束形成。SIM-MM的粒径为（19.2±1.3） nm,分散系数为0.094,Zeta电位为－11.3 mV,包封率及载药量分别为（95.31±0.80）%、（7.37±0.04）%,SIM-MM的临界胶束浓度介于纯F127和P123单一胶束之间。结论：制备出的SIM-MM粒径小并具有一定的缓释能力,可为后续研究辛伐他汀在治疗骨再生的体内研究与临床开发奠定基础。     

白藜芦醇胶束的制备及初步质量评价

摘要：目的:制备白藜芦醇聚合物胶束（RES-M）并对其进行初步的质量评价。方法:采用薄膜分散法,以普朗尼克F127（pluronic F127）作为载体材料,制备RES-M;以包封率和载药量为指标,通过单因素考察对RES-M的处方及工艺进行优化,并对最优处方制剂进行质量评价。结果:最优处方为pluronic F127与RES投料量比例为8∶1,旋蒸温度为45℃,旋蒸时间为25 min,水化介质为超纯水,水化体积为10 ml。最优处方的RES-M粒径为21.79 nm,多分散系数（PDI）为0.049,Zeta电位为-6.26 mV,包封率为（99.96±0.57）%,载药量为（10.67±0.37）%;RES-M的抗氧化能力与RES本身相当。结论:本试验成功制备RES-M,制备工艺简单,包封率与载药量均较高,为白藜芦醇制剂的研发提供了一定的理论基础。     

星点设计-效应面法优化美斯地浓聚乳酸纳米粒处方

目的星点设计-效应面法优化美斯地浓聚乳酸纳米粒处方。方法以复乳液中干燥法制备美斯地浓聚乳酸纳米粒,以包封率和载药量为评价指标,在单因素试验的基础上,用星点设计对显著性因素进行优化,并进行二项式方程拟合,以效应面法选取较好的工艺条件进行预测。结果以效应面法优选出的最佳工艺为:美斯地浓投药量为49.20 mg,PLA浓度为3.31%,PVA浓度为3.41%。制备的美斯地浓聚乳酸纳米粒平均包封率和载药量分别为(51.98±1.28)%和(7.01±0.31)%(n=3),与二项式拟合方程预测值相差<2%。结论应用星点设计-效应面法优化美斯地浓聚乳酸纳米粒制备工艺,能够快速、准确的得到最佳制备工艺,预测性良好。     

紫杉醇载药胶束的制备及体外评价

目的以胆酸修饰的聚乙二醇单甲醚-聚丙交酯-胆酸(m PEG-PDLLA-CA)聚合物为载体材料,制备紫杉醇载药胶束,并对载药胶束的处方和工艺进行优化。方法采用芘荧光法测定m PEGPDLLA-CA聚合物的临界胶束质量浓度,薄膜分散法制备紫杉醇载药胶束,以包封率和载药量为指标,应用Box-Behnken设计效应面法优化胶束的制备工艺。结果在优化条件下制备的载药胶束平均粒径为(54.35±1.80)nm,包封率为(92.74±0.64)%,载药量为(24.05±0.16)%,载药胶束在室温条件放置48 h,载药量无显著变化,制剂稳定性良好。结论用Box-Behnken设计效应面法优化紫杉醇载药聚合物胶束的制备工艺,该载药胶束物理稳定性良好,具有广阔的应用前景。     

Preparation and in vitro characterization of paclitaxel-loaded pH-responsive polymeric micelles based on poly(2-ethyl-2-oxazoline)-vitamin E succinate

To ensure the delivery of antitumor drugs to tumor site and quick release in tumor cells, we designed and prepared pH-sensitive polymeric micelles by combining cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EOz) with vitamin Esuccinate (VES), and then encapsulating paclitaxel (PTX) into the micelles self-assembled by poly(2-ethyl-2-oxazoline)-vitamin E succinate (PEOz-VES). The structure of the synthesized PEOz-VES was confirmed by ¹H NMR spectrum, and the molecular weight measured by GPC was 1212 g/mol. The pK_a of PEOz-VES with a low critical micelle concentration of (5.84±0.02) mg/L was determined to be 6.01. The PTX-loaded PEOz-VES polymeric micelles prepared by film hydration method were characterized to have a nanoscaled size of about 30 nm in diameter, a positive Zeta potential of 4.86 mV and uniform spherical morphology by TEM observation. The drug loading content and encapsulation efficiency were (2.63±0.16)% and (84.1±3.38)%, respectively. The in vitro release behavior of PTX from PEOz-VES micelles in PBS displayed pH-dependent pattern and was gradually accelerated with decrease of pH value, implying that the micelles could distinguish endo/lysosomal pH and tumor extracellular pH from physiological pH by accelerating drug release. Therefore, the designed PEOz-VES micelles might have significant promise for anti-cancer drug delivery.     

Genistein-loaded poloxamer 403/407 mixed micelles: preparation and pharmacokinetic study in rats

In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein.Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated.In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were (20.31±0.43) nm and (–8.94±0.35) mV, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/mL, which was about 130 times higher than that in water.Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension.The AUC_0–t andAUC_0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively.Consequently,poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.     

Pluronic F127 polymeric micelles for co-delivery of paclitaxel and lapatinib against metastatic breast cancer: preparation,optimization and in vitro evaluation

Abstract

The aim of this study was to develop and characterize the paclitaxel (PTX)-lapatinib (LPT) loaded micelles for simultaneous delivery against metastatic breast cancer. Efflux pump-mediated drug resistance influences the efficacy of chemotherapeutic regimens. However, in the newly developed delivery system, LPT was selected to act as chemosensetizer. LPT increases the intracellular level of PTX by inhibition of efflux pumps. Pluronic F127 was selected for the preparation of the micelles, and its critical micelle concentration was determined to be 0.012?mg/ml. D-optimal design was used to analyze the impact of different experimental parameters on PTX and LPT encapsulation ratio. PTX encapsulation ratio was optimized at 68.3%, while LPT encapsulation ratio found to be 70.1%. Transmission electron microscope analyses demonstrate that micelles possess a good core–shell structure without any sharp edge. Laser scattering method results indicated that size of the optimized micelles is 64.81?nm with acceptable polydispersity index (0.309). In vitro release studies showed a sustain release pattern. PTX–LPT-loaded micelles suppressed the proliferation of resistant T-47D cell line (IC₅₀?=?0.6?±?0.1?µg/ml) compared to binary mixture of PTX and LPT (IC₅₀?=?6.7?±?1.2?µg/ml). Therefore, it is concluded that the developed formulation might increase the therapeutic efficacy in drug resistant metastatic breast cancer.     

鞣花酸壳聚糖-海藻酸钠微球的制备工艺

目的:优化鞣花酸壳聚糖-海藻酸钠微球的最佳制备工艺。方法:采用一步法,以壳聚糖-海藻酸钠作为载体材料制备鞣花酸微球,并以微球载药量和包封率为考察指标,通过单因素筛选及正交设计优化出鞣花酸壳聚糖-海藻酸钠微球的制备工艺。用溶出仪在900 ml释放介质(pH 6.86)和120 r·min^-1转速条件下测定释放度。结果:优化工艺为海藻酸钠与药物比为3:1,氯化钙质量分数为2%,海藻酸钠质量分数为2%,壳聚糖质量分数为0.1%,温度为60℃,pH为5,所得鞣花酸平均粒径为(980±100)μm,平均载药量为27.22%,平均包封率为97.73%,48 h释放度为74.22%。结论:本制备工艺稳定,操作简便,重现性好,可用于鞣花酸壳聚糖-海藻酸钠微球的制备。     

紫杉醇Pluronic P105聚合物胶束的制备、表征与逆转肿瘤多药耐药性的体外研究

药物递送系统是克服肿瘤多药耐药性(MDR)的一种新策略。本文以聚合物胶束系统和难溶性药物紫杉醇(PTX)为研究对象，旨在制备一种新型的PTX给药系统，既能增溶难溶性药物，又具有克服肿瘤MDR的能力。以Pluronic P105为载体，采用固体分散-水化法制备PTX聚合物胶束，并以星点设计-效应面优化法进行处方优化。对其粒径、体外释放等性质进行表征后，以人耐药卵巢癌细胞SKOV-3/PTX为细胞模型，体外评价PTX聚合物胶束的细胞摄取及其逆转肿瘤细胞耐药性的作用。结果显示，聚合物胶束制剂的载药量约为1.1%、药物浓度约为700 μg·mL^-1、平均粒径约为24 nm。胶束制剂与普通制剂(Taxol)在6 h内的累积释放分别为45.4%和95.2%，前者具有较强的缓释作用；胶束制剂与Taxol对SKOV-3/PTX的IC₅₀值分别为1.14和5.11 μg·mL^-1，二者的耐药逆转指数(RRI)分别为9.65和2.15。胶束制剂可促进耐药细胞对P-糖蛋白(P-gp)底物(PTX或Rhodamine-123)的摄取。结果表明，Pluronic P105可有效增溶难溶性药物PTX，并形成具有较强缓释作用的纳米级聚合物胶束制剂，该制剂可显著提高PTX对人卵巢癌耐药细胞的细胞毒性，能逆转其耐药性。     

姜黄素聚合物胶束的制备及体外评价

目的:制备姜黄素的Soluplus聚合物胶束,并对其进行体外评价。方法:采用薄膜分散法制备姜黄素聚合物胶束;采用粒径测定仪、透射电镜、X-射线衍射(XRD)对其进行表征;采用紫外分光光度法测定胶束的包封率和载药量;采用动态膜透析法考察载药胶束的体外释药特性。结果:薄膜分散法制备的胶束呈球形或类球形,平均粒径为(65.54±2.57)nm,平均包封率为(87.73±2.94)%,平均载药量(7.96±2.13)%;XRD结果表明姜黄素以无定型状态或分子状态包载在聚合物胶束中;体外释放结果表明姜黄素的soluplus聚合物胶束具有缓释作用。结论:该胶束制备工艺简单,其粒径、包封率、载药量可控,具有缓释作用。     

姜黄素聚合物胶束的制备及抗肿瘤活性评价

目的:制备姜黄素的维生素E聚乙二醇琥珀酸酯(TPGS)聚合物胶束,从而改善姜黄素的水溶性和抗肿瘤活性。方法:以TPGS为载体材料,采用薄膜水化法制备姜黄素胶束;以包封率和粒径为指标,考察水化温度、水化时间、药载比和水化体积的影响;以包封率、粒径、载药量为指标,经四因素三水平正交试验,确定姜黄素/TPGS胶束的最佳制备工艺;考察姜黄素/TPGS胶束的体外释放度;利用MTT法测试姜黄素/TPGS的体外抗肿瘤活性。结果:姜黄素/TPGS胶束的最佳药载比为1∶40,水化温度为60℃,水化时间为30 min,水化体积为6 mL;所得胶束平均粒径为11.02 nm, Zeta电位为-11.31,载药量为2.65%,包封率为96.20%;姜黄素/TPGS 48 h体外累积释放率为78%,具有一定的缓释性;MTT法表明,姜黄素/TPGS具有良好的抗肿瘤活性。结论:该文采用薄膜水化法制备了一种稳定的姜黄素/TPGS胶束,改善了姜黄素的水溶性,明显提高了其抗肿瘤效果。     

K237修饰的紫杉醇热敏脂质体的制备、处方优化和体外释放度研究

目的：以紫杉醇（PTX）为模型药物,构建K237修饰的热敏脂质体（K237-PTX-TSL）,系统研究K237-PTX-TSL的制备工艺、理化性质,处方优化和体外释放特性。方法：采用NH2末端PEG化技术合成靶向磷脂材料DSPE-PEG-K237,采用薄膜分散法制备K237修饰的紫杉醇热敏脂质体（K237-PTX-TSL）,HPLC法测量药物的包封率和载药量;采用马尔文激光粒度仪测定K237-PTX-TSL的粒径及粒径分布和Zeta电位;利用差示扫描量热法（DSC）测量相变温度（Tm）;采用透析袋法测量相变温度下的释药规律并拟合释放曲线。结果：优化的处方为：DPPC：DSPG：MSPC：DSPE-PEG-NHS=9：1：1：1,药脂比为1/20,磷脂浓度为5.0%,DSPE-PEG-K237占处方磷脂总量为1%。制备得到的K237-PTX-TSL包封率为（94.23±0.76）%;粒测得K237-PTX-TSL粒径为（88.3±4.7） nm,电荷为-4.5 mv,PDI值为0.13±0.01;K237-PTX-TSL的相变温度为40.805℃,K237-PTX-TSL在42℃时的体外释放最优拟合为一级动力学模型,方程为In（100-Q）=-0.063 8t+4.713 0（r=0.994 4）。42℃时20 min内紫杉醇累计释放度为72.45%,60 min的累计释放度为98.84%。结论：K237修饰的热敏脂质体载药量和包封率较高、粒径较小,热敏释药性质良好,1 h内药物基本释放完全。     

The effect of core composition in biodegradable oligomeric micelles as taxane formulations.

Docetaxel (DCTX) and paclitaxel (PTX) are very potent anti-cancer drugs, but the currently marketed formulations, Taxotere and Taxol, respectively, are associated with vehicle-related toxicity. An attractive alternative to formulate these hydrophobic cytotoxic agents are polymeric micelles. In this study, the loading of taxanes into oligomeric micelles composed of mPEG750-b-oligo(epsilon-caprolactone)5 (mPEG750-b-OCL5) with a hydroxyl (OH), benzoyl (Bz) or naphthoyl (Np) end group was investigated. Next, the release characteristics and cytotoxicity of the loaded micelles were studied. MPEG750-b-OCL5 -OH micelles loaded with taxanes formed unstable particles with rapid leakage of the drug. In contrast, the presence of an aromatic end group (Bz or Np) resulted in the formation of small (10nm), almost monodisperse micelles with stable encapsulation of 10% (w/w) of PTX or DCTX. This was ascribed to a better compatibility between the micellar core and the drug as compared to the oligomers with the hydroxyl end group. 1H NMR studies showed that the micellar core was liquid, and that PTX was molecularly dissolved in the core. The in vitro stability was studied in PBS at 37 degrees C, which showed that leakage of PTX from 10% and 5% (w/w) loaded mPEG750-b-OCL5-Bz micelles started after 8 and 24h, respectively. The presence of albumin did not affect the stability, suggesting that the micelles are not destabilised and the drug was not extracted from the micellar core by this protein. The in vitro cytotoxic effect of the taxane-loaded micelles on C26 carcinoma cells was comparable to that of the commercial formulations, but the empty micelles were far less toxic than the Cremophor EL vehicle. The results show that mPEG-b-oligo(epsilon-caprolactone) micelles hold good promise for the formulation of taxanes.     

Pharmacokinetics and biodistribution of polymeric micelles of paclitaxel with pluronic P105/poly(caprolactone) copolymers

A novel polymeric micellar formulation of paclitaxel (PTX) with Pluronic/poly(caprolactone) (P105/ PCL50) has been developed with the purpose of improving in vitro release and in vivo circulating time of PTX in comparison to the current Taxol injection. This study was designed to investigate the preparation, in vitro release, in vivo pharmacokinetics and tissue distribution of the PTX-loaded, biodegradable, polymeric, P105/PCL50 micelle system. The drug-loaded micelles were prepared by dialysis using the hydrophobic drug, PTX, and the nonionic surfactant Pluronic P105 modified with a low molecular weight PCL. The results of dynamic light scattering (DLS) experiment indicated that the PTX-loaded micelles had a mean size of approximately 150 nm with narrow size distribution (polydispersity index < 0.3). The in vitro release study showed that the release of PTX from the micelles exhibited a sustained release behavior. A similar phenomenon was also observed in a pharmacokinetic assessment in rats, in which t1/2 beta and AUC of the PTX micelle formulation were 4.0 and 2.2-fold higher than that of Taxol injection. The biodistribution study in mice showed that the PTX micelle formulation not only decreased drug uptake by the liver, but also prolonged drug retention in the blood, and increased the distribution of drug in kidney, spleen, ovaries and uterus. These results suggested that the P105/ PCL50 polymeric micelles may efficiently load, protect and retain PTX in both in vitro and in vivo environments, and could be a useful drug carrier for i.v. administration of PTX.