环孢素A-Eudragit S100纳米粒冻干粉制剂在犬体内的药动学

目的:研究环孢素A-Eudragit S100纳米粒冻干粉制剂(freeze-dried cyclosporine A-Eudragit S100 nanoparticles,CyA-S100-NP)在家犬体内药动学及相对生物利用度。方法:以双周期交叉随机试验设计法,高效液相色谱法测定6只家犬口服给予环孢素A-Eudragit S100纳米粒冻干粉硬胶囊和新山地明微乳软胶囊(Neoral)后环孢素A的血药浓度,采用3P97软件计算药动学参数。结果:经3P97软件拟合,环孢素A的药动学过程符合二室模型。与Neoral相比,CyA-S100-NP的AUC显著增大(P<0.05),CL显著降低(P<0.05),相对生物利用度为135.9%。结论:CyA-S100-NP可促进药物口服吸收,显著提高环孢素A的生物利用度,有望开发成为一种新型口服环孢素A纳米粒固体制剂。     

蛇床子素-pH敏感性纳米粒的制备及其在大鼠体内的药代动力学

目的:制备蛇床子素-Eudragit S100纳米粒(Ost-S100-NP)及其冻干制剂(Fd-Ost-S100-NP),并考察相关特性;考察蛇床子素、纳米粒制剂和冻干制剂在大鼠体内的药代动力学及相对生物利用度。方法:以乳化-溶剂扩散法联合冷冻干燥技术制备Ost-S100-NP胶体溶液及其冻干粉末;动态透析法研究其体外释药动力学;以HPLC测定大鼠灌胃后血浆中的Ost浓度,3P97程序计算药代动力学参数。结果:Ost-S100-NP和Fd-Ost-S100-NP的平均粒径分别为(55.4±2.1)和(87.7±2.3)nm;包封率>95%;电镜下呈均匀规则的圆球形;且纳米粒制剂在pH>6.0的释放介质中释药速率明显增大,具有显著pH敏感性;药物在大鼠体内药代动力学均符合二室模型,Ost-S100-NP和Fd-Ost-S100-NP的相对生物利用度分别为原料药的161.1%和118.4%。结论:以pH敏感性材料Eudragit S100为载体有望开发成一种高效、低毒的蛇床子素纳米制剂。     

环孢素A-羟丙甲纤维素酞酸酯纳米粒的大鼠相对生物利用度

目的制备环孢素A-HPMCP(两种型号HP50与HP55)纳米粒，并与新山地明(Neoral)进行大鼠相对生物利用度与药物动力学行为的比较。方法以溶剂-非溶剂法制备CyA-HP50 NP与CyA-HP55 NP，用HPLC法测定其相对生物利用度，并用3P97程序计算药代动力学参数。结果3种制剂的血药浓度-时间数据均以2室模型拟合最佳。与Neoral相比，CyA-HP50 NP与CyA-HP55 NP的相对生物利用度分别为82.3%和119.6%，均无显著性差异；CyA-HP50 NP与CyA-HP55 NP的K₁₀均较小(P<0.05)，说明药物消除较慢。与CyA-HP50 NP相比，CyA-HP55 NP的相对生物利用度为145.3%，有显著性差异(P<0.01)。结论CyA-HPMCP NP 制备方法简便，生物利用度高，可望开发为一种新的制剂。     

重组水蛭素-2鼻腔黏附纳米粒及其冻干粉药代动力学和抗凝活性研究

目的:对重组水蛭素-2(rHV2)鼻腔壳聚糖(CS)黏附纳米粒及其冻干粉进行药代动力学和抗凝活性评价。方法:采用呈色肽比色法检测rHV2血药浓度;以正常麻醉大鼠为模型,测定经鼻腔给予rHV2生理盐水溶液、rHV2纳米粒溶液及其纳米粒冻干粉复溶液的药-时曲线,计算药代动力学参数及与rHV2生理盐水溶液皮下注射给药的相对生物利用度;同时以部分凝血活酶时间(APTT)为指标比较它们的抗凝活性。结果:rHV2纳米粒比其生理盐水溶液鼻腔给药的相对生物利用度提高了8.99倍,rHV2纳米粒冻干粉复溶液也较其生理盐水溶液鼻腔给药的相对生物利用度提高了8.48倍。rHV2纳米粒及其冻干粉鼻腔给药后,均表现出显著的抗凝血活性,而rHV2生理盐水鼻腔给药则基本无效。结论:制备的rHV2鼻腔壳聚糖黏附纳米粒制剂具有较高的生物利用度,制成冻干粉后,仍保持较高的生物利用度。由于rHV2冻干粉制剂稳定性更高,有望成为rHV2经鼻腔给药的有效制剂。     

胰岛素肠溶PLGA纳米粒的制备及体内外性质的评价

目的制备肠溶胰岛素PLGA纳米粒,并对其理化性质、体外释药以及在正常大鼠体内的降血糖效果进行研究。方法采用改良的乳化溶剂扩散法分别制备了胰岛素PLGA纳米粒和肠溶胰岛素纳米粒(PLGA HP55 NP、PLGA HP50 NP)。通过激光粒度测定仪测定粒径大小,系统考察了肠溶材料HP55的用量及类型对纳米粒性质的影响,以及各种纳米粒在人工胃液、人工肠液中的释药行为和其在正常大鼠体内的降血糖作用,并与PLGA HP50 NP进行了比较。结果制得的最终处方的肠溶纳米粒(PLGA HP55)的粒径为(169±16)nm,胰岛素的载药量为(3.17±0.24)%。肠溶纳米粒在人工胃液中的释药速率明显低于PLGA纳米粒。PLGA纳米粒和肠溶PLGA HP50、PLGA HP55纳米粒均能显著降低正常大鼠的血糖浓度,其在正常大鼠体内24 h相对于皮下注射给药的相对生物利用度分别为(5.46±0.7)%、(6.31±0.64)%和(8.72±0.5)%。结论胰岛素肠溶纳米粒可以有效抑制胰岛素在人工胃液中的释放,与PLGA纳米粒相比显著降低正常大鼠的血糖浓度。其中PLGA HP55纳米粒的降糖作用显著高于PLGA HP50纳米粒。pH值高的纳米粒有望成为胰岛素口服给药的有效载体。     

紫杉醇PLGA纳米粒大鼠生物利用度的测定

目的制备紫杉醇PLGA纳米粒,以紫杉醇注射液为参比制剂,进行生物利用度考察。方法以乳化-溶剂挥发法制备紫杉醇纳米粒,用HPLC法测定全血中的药物浓度,计算紫杉醇纳米粒的生物利用度。结果紫杉醇纳米粒外观圆整,平均粒径为99.0nm,Zeta电位58.3mV,平均包封率为56.77%,载药量为7.10%。大鼠口服给药后,紫杉醇纳米粒的绝对生物利用度达到19.5%。结论纳米载药系统的制备有利于促进紫杉醇的吸收,提高了其口服生物利用度。     

低分子肝素pH敏感混合聚合物纳米粒大鼠体内生物利用度研究

目的建立生色底物法测定大鼠血浆中低分子肝素(LMWH)含量的方法,研究p H敏感巯基壳聚糖/O-羧甲基壳聚糖(TCS/O-CMC)混合聚合物纳米粒在SD大鼠体内的相对生物利用度。方法采用生色底物法以SD大鼠为研究对象,测定LMWH注射液、LMWH溶液、p H敏感TCS纳米粒和p H敏感TCS/O-CMC混合聚合物纳米粒单剂量给药后的血药浓度,并用Win Nonlin软件计算药动学参数和生物利用度。结果 LMWH溶液、p H敏感TCS纳米粒和p H敏感TCS/O-CMC混合聚合物纳米粒的药动学参数如下:Cmax分别为(0.103±0.025)、(0.425±0.046)和(0.522±0.042)U/ml。AUC0→∞分别为(0.5±0.3)、(4.7±1.0)和(8.0±2.0)U·ml-1·h。相对生物利用度分别为2.10%、20.70%和34.98%(P<0.05)。结论 p H敏感TCS/O-CMC混合聚合物纳米粒可显著提高LMWH的口服生物利用度。     

壳聚糖包衣对胰岛素聚酯纳米粒胃肠道吸收的促进作用

目的研究壳聚糖包衣胰岛素乳酸/羟基乙酸共聚物(PLGA)纳米粒对胰岛素胃肠道吸收的促进作用。方法以双乳化法制备了胰岛素PLGA复乳,壳聚糖用作稳定剂,制备了包衣纳米粒;观察了粒子大小、表面形态及Zeta电位;测定了包封率;考察了体外释药行为;以糖尿病大鼠评价降血糖水平。结果包衣纳米粒粒度分布均匀,隐约可见层状结构,壳聚糖可改变粒子表面Zeta电位,提高包封率,降低突释;灌服10 u·kg^-1包衣纳米粒,14～16 h降血糖水平显著高于未包衣纳米粒(P＜0.05),药理相对生物利用度提高到15.4%。结论壳聚糖包衣聚酯纳米粒可以促进胰岛素胃肠道吸收。     

PEG-PLA-α-细辛脑纳米粒经鼻腔、静脉给药后的药动学研究

目的 采用与静脉注射对比的方式,研究聚乙二醇-聚乳酸-α-细辛脑纳米粒（PEG-PLA-α-细辛脑纳米粒）鼻腔给药后在大鼠体内的药物动力学。方法 以大鼠为动物模型,采用血药动力学、脑药动力学及荧光标记法对比研究PEG-PLA-α-细辛脑纳米粒经鼻腔给药与静脉注射后药物/纳米粒在大鼠体内的分布情况。结果 PEG-PLA-α-细辛脑纳米粒静脉注射及鼻腔给药后血浆中的AUC_（0-∞）分别为（11032.4±1 827.1）ng·mL^-1·min及（5 992.9±717.5）ng·mL^-1·min,C_max分别为（421.9±100.2）ng·mL^-1及（171.7±26.3）ng·mL^-1,PEG-PLA-α-细辛脑纳米粒鼻腔给药后的绝对生物利用度F为54.3%。PEG-PLA-α-细辛脑纳米粒静脉注射后α-细辛脑在脑组织中的C_max与鼻腔给药后α-细辛脑在脑组织中的浓度C_max分别为（217.9±29.9）ng·mL^-1及（334.2±62.7）ng·mL^-1,PEG-PLA-α-细辛脑纳米粒静脉注射与鼻腔给药后的AUC_brain/AUC_plasma值分别为1.37和2.85,且两者具有统计学意义。PEG-PLA-α-细辛脑纳米粒鼻腔给药后的药物脑靶向效率及鼻-脑传递百分比分别为208.03%及52.01%。荧光标记法结果显示,PEG-PLA-α-细辛脑纳米粒鼻腔给药后脑靶向性比静脉注射后更强。结论 PEG-PLA-α-细辛脑纳米粒适合于鼻腔给药治疗脑部疾病。     

环孢素A聚乳酸纳米粒胶体的制备与大鼠生物利用度的测定环孢素A聚乳酸纳米粒胶体的制备与大鼠生物利用度的测定

目的研究环孢素A聚乳酸纳米粒胶体(CyA-NP)的制备处方与工艺,并以新山地明(Neoral)为参比制剂,进行相对生物利用度考察。方法以溶剂-非溶剂法制备CyA-NP,用HPLC法测定全血中的药物浓度,计算胶体的生物利用度。结果胶体中的纳米粒均匀圆整,粒径为57.5 nm,药物回收率大于90%。CyA-NP的AUC0-72为29.06 mg·h·L^-1,Neoral的AUC0-72为28.59 mg·h·L^-1,与Neoral相比,CyA-NP的相对生物利用度为101.6%,峰浓度较小(P<0.05),吸收较慢(P<0.05),消除亦较慢(P<0.1)。结论以溶剂-非溶剂法可以简便制得CyA-NP,其大鼠相对生物利用度与Neoral相比无显著性差异,有望成为Neoral的代用品。     

pH-sensitive nanoparticles for improving the oral bioavailability of cyclosporine A

The purpose of this work was to improve the oral bioavailability of cyclosporine A (CyA) by preparation the CyA-pH sensitive nanoparticles. The CyA-pH sensitive nanoparticles were prepared by using poly(methacrylic acid and methacrylate) copolymer. The characterization and the dispersion state of CyA at the surface or inside the polymeric matrices of the nanoparticles were investigated. The in vitro release studies were conducted by ultracentrifuge method. The bioavailability of CyA from nanoparticles and Neoral microemulsion was assessed in Sprague–Dawley (SD) rats at a dose of 15 mg/kg. The particle size of the nanoparticles was within the range from 37.4 ± 5.6 to 106.7 ± 14.8 nm. The drug entrapped efficiency was very high (from 90.9 to 99.9%) and in all cases the drug was amorphous or molecularly dispersed within the nanoparticles polymeric matrices. In vitro release experiments revealed that the nanoparticles exhibited perfect pH-dependant release profiles. The relative bioavailability of CyA was markedly increased by 32.5% for CyA-S100 nanoparticles (P < 0.05), and by 15.2% and 13.6% for CyA-L100-55 and CyA-L100 nanoparticles respectively, while it was decreased by 5.2% from CyA-E100 nanoparticles when compared with the Neoral microemulsion. With these results, the potential of pH-sensitive nanoparticles for the oral delivery of CyA was confirmed.     

环孢素A硬脂酸纳米球的实验研究

目的：探讨硬脂酸纳米球作为新型药物载体的可能性。方法：制备了硬脂酸纳米球(SA-NP),用电镜考察其形态,测定了各种理化特性;以环孢素A(CYA)为模型药物,制备了环孢素A硬脂酸纳米球(CYA-SA-NP);对其进行了红外光谱测定和差示扫描量热分析;建立了测定CYA-SA-NP和血中CYA的HPLC法。以市售CYA微乳型口服液为对照,测定了口服CYA-SA-NP在大鼠体内的药代动力学参数和相对生物利用度。结果：CYA-SA-NP的平均粒径为316.6nm,CYA的平均包封率为88.39%,CYA和硬脂酸之间无化学反应发生;CYA-SA-NP的相对生物利用度接近80%,而且达峰时间较晚,具有明显的缓释效果。结论：硬脂酸纳米球将可能成为一种新型的药物载体。     

Positively charged nanoparticles for improving the oral bioavailability of cyclosporin-A

In this study, cyclosporin-A (Cy-A) a highly lipophilic, poorly absorbable drug can be prepared easily and reproducibly as positively and negatively charged nanoparticles with the aim of improving its bioavailability and reducing its inter- and intra-individual variability. The nanoparticles were prepared by emulsification solvent diffusion method, using lecithin and poloxamer 188 as emulsifiers, and chitosan HCl, gelatin-A or sodium glycocholate (SGC) as charge inducing agents. The prepared nanoparticles were evaluated with respect to particle size, zeta potential, drug content and encapsulation efficiency. The bioavailability Cy-A from nanoparticles in comparison with the currently available Cy-A microemulsion (Neoral) were assessed in beagle dogs. The results obtained revealed that, it was possible to prepare Cy-A as nanoparticles with size range of 104-148 nm. Chitosan HCl and gelatin-A nanoparticles exhibited +31.2 and +23.1 mV zeta potential, respectively; while SGC-nanoparticles exhibited -41.6 mV zeta potential. The in vivo results showed that, chitosan-nanoparticles gave the highest C(max) (2762.8 ng/ml) of Cy-A after 2.17 h (T(max)), while SGC-nanoparticles gave the lowest one (1202.4 ng/ml after 4.0 h). Furthermore, AUC(0-24) of Cy-A from chitosan-nanoparticles was markedly increased by about 2.6-fold when compared with SGC-nanoparticles and increased by about 1.8-fold when compared with the reference Neoral microemulsion. However, in case of gelatin-nanoparticles the AUC(0-24) of Cy-A increased by about 1.8 and 1.2-fold when compared with SGC-nanoparticles and the reference Neoral microemulsion, respectively. The relative bioavailability of Cy-A from chitosan-nanoparticles was increased by about 73%, and by about 18% from gelatin nanoparticles, while it was decreased by about 36% from SGC-nanoparticles.     

环孢素A纳米粒在小鼠体内的药动学及组织分布

目的:研究环孢素A纳米粒(CyA-NP)在小鼠体内组织分布,并与市售新山地明微乳制剂(Neoral)的组织分布特征进行比较。方法:取小鼠120只,随机分为20组,每组6只,前10组小鼠按25mg·kg-1的剂量灌胃给予Neoral溶液,后10组灌胃给予等剂量的CyA-NP溶液,于给药后不同时间摘眼球取血及制备各组织样品,各样品中的药物采用液-液萃取法提取,建立高效液相色谱(HPLC)法测定血液及各组织中不同时间的药物浓度,以各组织药动学参数和靶向参数为评价指标,对2种制剂在小鼠体内的分布特征和靶向性进行评价。结果:血药浓度测定方法的回收率均大于72%,日内、日间精密度良好;2种制剂在小鼠体内均符合口服吸收二室模型;与Neoral比较,CyA-NP给药后CyA在血液及各组织中药物浓度较快达到峰值,相对生物利用度为162.5%;在体内药物浓度分布趋势为肝>心>肾>脾>肺,在肝中无蓄积。结论:与Neoral比较,CyA-NP体内分布迅速,组织分布广泛,促进了药物口服吸收,改变了CyA在体内的组织分布,有助于提高临床用药水平,对局部脏器移植有更好的疗效。     

Bioavailability of Sandimmun® versus Sandimmun Neoral®: a meta-analysis of published studies

For the past 25 years, cyclosporine A (CyA) has played a pivotal role in transplant immunosuppressant therapy. From the availability of the 2 primary marketed formulations (Sandimmun? and Sandimmun Neoral?, Novartis), confusion has existed with regard to whether these two formulations are bioequivalent. Due to the underlying clinical relevance of this information, we therefore conducted a meta-analysis of all available comparative pharmacokinetic studies to assess whether the two different CyA formulations, Sandimmun? and Sandimmun Neoral?, can be considered bioequivalent. All clinical studies that compared the bioavailability of the 2 formulations in organ transplant recipients were considered for analysis. We searched computerised databases (Embase/Excerpta Medica and Medline/PubMed) from their inception to May 2010. Only studies with AUC values determined at 12 hours were considered for analysis. Relative bioavailability was calculated with 90 percent confidence intervals (CI) for Sandimmun? (test substance) versus Sandimmun Neoral? (reference substance) according to Schuirmann?s Two One-Sided Tests Procedure and the Classical Shortest CI. Homogeneity of data was tested using the Χ(2) test. Fifteen studies were considered for meta-analysis and none of these studies reported AUC values in the 80-125 percent range required for the bioequivalence of two formulations. The overall bioavailability for Sandimmun? versus the microemulsion formulation Sandimmun Neoral? was 76 percent, with upper CI limits lower than 80 percent in some cases. Mean AUC values for Sandimmun? were significantly lower than those for Sandimmun Neoral? (p<0.01). This study demonstrates that the 2 main cyclosporine formulations, Sandimmun? and Sandimmun Neoral?, cannot be considered bioequivalent.     

Improved Dose Linearity of Cyclosporine Pharmacokinetics from a Microemulsion Formulation

The pharmacokinetic dose proportionality and relative bioavailability of cyclosporine from a microemulsion formulation (Sandimmune Neoral) were compared to those of the commercial formulation (Sandimmune) over the dosage range 200 to 800 mg. Single oral administrations were given as soft gelatin capsules in an open randomized study with 48 healthy volunteers. Whole-blood cyclosporine concentrations were determined by a specific monoclonal radio-immunoassay. In comparison to Sandimmune, the absorption rate (maximum concentration) and systemic availability (area under the curve) of cyclosporine were greater for Sandimmune Neoral at all dose levels investigated. The area under the curve for Sandimmune increased in a less than proportional manner with respect to dose, whereas that for Sandimmune Neoral was consistent with linear pharmacokinetics. Because of this difference, no global assessment of relative bioavailability could be performed. The relative bioavailability of cyclosporine from Sandimmune Neoral ranged from 174 to 239% compared to Sandimmune, depending on the dose level. The improvements in oral bioavailability and dose linearity of cyclosporine exposure after administration as Sandimmune Neoral should facilitate more accurate dosage titration in the clinical setting.     

Comparative bioavailability of the microemulsion formulation of cyclosporine (Neoral) with a generic dispersion formulation (Cicloral) in young healthy male volunteers

The aim of this study was to compare the bioavailability of cyclosporine (CyA) from the generic dispersion formulation Cicloral (CIC) with the microemulsion formulation Neoral (NEO) and the original Sandimmune (SIM) capsules after single doses of 100, 300, or 600 mg of drug, respectively. The study was performed according to an open 3-period cross-over design with 12 young healthy male volunteers for each dosage. The concentrations of CyA and its main metabolites were determined by high performance liquid chromatography in whole blood and urine up to 48 hours postdosing. Peak concentrations and area under the time-concentration curve were greater for the NEO and CIC formulations compared with SIM, and the mean bioavailability of CIC was significantly (P<0.05) lower compared with NEO. The bioavailability of SIM compared with NEO was 54% to 71%, in agreement with previous results. Bioequivalence was not demonstrated between CIC (test) and NEO (reference) as the 90% confidence intervals were outside the 80% to 125% guidelines based on log-transformed AUCs, and were 75.2% to 87.7% at 100 mg, 79.2% to 91.8% at 300 mg, and 76.6% to 94.5% at 600 mg doses. The respective values for Cmax were 78.9% to 94.6%, 80.7% to 95.0%, and 71.4% to 84.1%. A good correlation was demonstrated between the urinary recovery of CyA and the AUC4. Therefore, the urinary recovery of CyA may be helpful as a surrogate parameter for the systemic exposure of patients to CyA. Whereas the relative amount of hydroxylated metabolites (AM1, AM9, AM1c) was similar for all formulations and doses, the urinary recovery of the N-demethylated metabolite AM4N decreased with increasing dose indicating saturable metabolism. No relationship could be demonstrated between CYP3A activity using dextromethorphan as a probe for the metabolic clearance of CyA.