雷公藤甲素聚乳酸纳米粒对大鼠睾丸组织的影响

目的　观察采用聚乳酸纳米粒能否减轻雷公藤甲素的大鼠睾丸毒性。方法　雄性Wistar大鼠分别ig 0 .2及 0 .6mg·kg- 1雷公藤甲素 (非纳米粒组 )及其聚乳酸纳米粒混悬液 (纳米粒组 ) ,连续给药 15d ,以ig生理盐水的大鼠为对照组 ,测定睾丸的脏器系数及其组织匀浆液中酸性磷酸酶 (ACP)活性和果糖含量 ,光镜观察睾丸组织的病理学变化。结果在 0 .6mg·kg- 1剂量下 ,非纳米粒组睾丸ACP活性和果糖的含量均明显低于纳米粒组 (P <0 .0 5 )。光镜观察显示 ,雷公藤甲素 0 .6mg·kg- 1可引起大鼠睾丸的损伤 ,非纳米粒组引起的病变程度明显重于纳米粒组 ,主要表现为睾丸萎缩 ,各级生精细胞变性、坏死、数量减少或消失 ,出现了多核巨细胞。结论以聚乳酸作为药物载体的纳米体系 ,可明显减轻雷公藤甲素对睾丸的毒性     

冬凌草甲素固态类脂纳米粒在小鼠体内的组织分布及兔体内的药代动力学

目的考察冬凌草甲素固态类脂纳米粒在动物体内的组织分布及药代动力学特性。方法建立生物样品中冬凌草甲素的HPLC测定法，比较冬凌草甲素普通注射液和固态类脂纳米粒注射液的体内分布特点与药代动力学参数。结果冬凌草甲素固态类脂纳米粒在肝、脾、肺、心及肾中的相对摄取率分别为4.25%，3.44%，1.19%，0.52%和0.60%。静脉注射后的药-时曲线表明体内过程符合三室模型，其各相半衰期分别为T_1/2π=0.087 h，T_1/2α=1.65 h，T_1/2β=32.36 h，中心分布容积V_C=0.66 mL·kg^-1。结论冬凌草甲素固态类脂纳米粒能够增强药物的肝脾靶向性，提高药物生物利用度，并在一定程度上延长药物在动物体内的循环时间。固态类脂纳米粒可能成为冬凌草甲素的一种新型药物载体。     

灯盏乙素-PEG-PLGA载药纳米粒的制备及质量评价

目的:制备灯盏乙素-聚乙二醇-聚乳酸/羟基乙酸共聚物(PEG-PLGA)载药纳米粒,优化其处方,并进行质量评价。方法:采用复乳-溶剂蒸发法制备灯盏乙素-PEG-PLGA载药纳米粒。以包封率为评价指标,以初乳与外水相的比例、灯盏乙素和PEG-PLGA质量浓度为因素,通过单因素试验和正交试验优化处方;测定最优处方所制纳米粒的表观形态、粒径、Zeta电位、载药量、包封率和稳定性。结果:最优处方为初乳与外水相的比例1∶15,灯盏乙素质量浓度10 mg/ml,PEG-PLGA质量浓度15 mg/ml。所制得纳米粒为圆形或椭圆形,平均粒径为(78.54±2.21)nm,Zeta电位为(-23.07±1.39)m V,载药量为(1.67±0.12)%,包封率为(45.32±1.29)%;纳米粒在4℃下保存3个月内粒径和包封率无明显变化。结论:成功制得具有较好理化性质和稳定性的灯盏乙素-PEG-PLGA纳米粒。     

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。     

改良自乳化-溶剂扩散法制备甲基莲心碱纳米粒的研究

目的制备甲基莲心碱纳米粒(NEF-NP),并采用正交试验设计对甲基莲心碱纳米粒制备工艺进行优化。方法以包封率和载药量为评价指标,采用聚乳酸-羟基乙酸共聚物(PLGA)为载体,丙酮-无水乙醇为有机溶剂,通过正交设计优化改良自乳化-溶剂扩散法制备载NEF的PLGA载药纳米粒的处方工艺。结果优化的最佳处方工艺为:PLGA的浓度为20 mg.mL-1,NEF的投药量为3.3 mg,PVA浓度为1.0%,水相与有机相的体积比为8∶1。最佳条件下制得的纳米粒平均包封率达(70.35±1.16)%,载药量(2.33±1.08)%,平均粒径为(213.5±2.7)nm。结论最佳处方工艺制备的NEF-PLGA纳米粒具有较高的包封率、载药量和较小的粒径。     

布洛芬聚氰基丙烯酸烷酯纳米粒的制备

目的制备布洛芬聚氰基丙烯酸烷酯纳米粒(IBU-PACA-NP)。方法采用乙醚界面缩聚法制备布洛芬聚氰基丙烯酸烷酯纳米粒;以包封率、载药量为指标,在单因素考察处方及工艺条件基础上,采用正交设计法L9(34)对处方进行优化。结果按优化处方制备的纳米粒平均粒径为166 nm,包封率为96.60%,载药量为17.83%,Zeta电位为-20.2 mV。结论乙醚界面缩聚法制备的布洛芬聚氰基丙烯酸烷酯纳米粒粒径小,包封率和载药量符合要求,可用于口服或注射给药。     

共载阿霉素和依克立达的PLGA纳米粒的制备及表征

目的 建立药物测定方法,并制备共载阿霉素和依克立达的PLGA纳米粒。方法 利用紫外分光光度法（UV）和高效液相色谱法（HPLC）分别建立阿霉素和依克立达的测定方法;采用纳米沉淀法制备共载纳米粒,通过调节两药的投药比,优化处方,考察纳米粒的粒径、形态、包封率、载药量以及体外释放。结果 阿霉素在1~40 μg/ml浓度范围内线性关系良好,标准曲线回归方程为A=0.021C+0.002,r=0.999 5; 依克立达在0.5~100 μg/ml浓度范围内线性关系良好,标准曲线回归方程为A=120 742.462 6C+1 974.570 4,r=1.000 0;通过处方优化,共载纳米粒的粒径约为50 nm,分布均一,呈圆形,阿霉素和依克立达的包封率分别为56.58%、51.66%,载药量分别为1.48%、1.85%,两药摩尔比约为1：1;体外释放缓慢。结论 分别建立了方便快捷、结果准确、重复性好的阿霉素和依克立达的检测方法,并且制备了分散性好、粒径较小的纳米粒,为后续实验提供基础。     

还原响应型靶向自载药纳米粒的制备及其体外评价

目的 制备靶向性的自载药纳米粒(HA-ss-Bai NPs)，并考察其作为药物载体递送姜黄素(curcumin，Cur)的可行性。方法 制备二硫键连接的透明质酸(hyaluronic acid，HA)-黄芩苷(baicalin，Bai)聚合物，利用核磁共振氢谱(hydrogen nuclear magnetic resonance spectroscopy，¹H-NMR)、红外光谱(infrared spectroscopy，IR)确证聚合物的结构；采用超声法制备自组装纳米粒，并对其粒径、Zeta电位进行表征；采用芘荧光探针法测定纳米粒的临界聚集浓度(critical aggregation concentration，CAC)；测定载Cur纳米粒包封率和载药量；MTT试验考察载药纳米粒的体外抗肿瘤活性。结果 制备HA-ss-Bai NPs，最小粒径为(124.3±6.5) nm，CAC值为(0.023 8±0.003 5) mg·mL^–1。测得Cur/HA-ss-Bai NPs的粒径为(172.5±3.2) nm，载药量为(17.08±0.25)%，包封率为(51.23±3.97)%。体外释放表明药物在还原条件下可快速释放，MTT试验表明Cur/HA-ss-Bai NPs对HepG2肝癌细胞生长具有显著的抑制作用。结论 制备的Cur/HA-ss-Bai NPs粒径均匀、载药量较高，具有良好的还原响应性和抗肿瘤活性，同时提高了Bai与Cur的体外抗肿瘤效果。     

季铵化壳聚糖胰岛素纳米粒的制备、处方优化及其初步药效学实验

目的 采用正交设计试验优化载胰岛素季铵化壳聚糖纳米粒的处方工艺,并初步考察其降糖效果。 方法 用离子交联法制备载胰岛素的季铵化壳聚糖纳米粒,用正交试验确定其最佳处方工艺。用透射电子显微镜观察纳米粒的表面形态;用粒径/Zeta电位仪测定纳米粒的粒径和Zeta电位;用高效液相色谱(HPLC)法测定纳米粒的包封率、载药量及体外释放情况。对糖尿病大鼠皮下注射给药,对其药效学进行初步考察。 结果 制得的纳米粒呈球形,分布均匀;平均粒径(63.26±1.88) nm;Zeta电位(33.1±0.3) mV;包封率(37.92±2.11)%;载药量(5.42±0.3)%;24 h累计释放率63.83%。皮下注射给药8 h,糖尿病大鼠血糖较单纯注射胰岛素组下降平缓,且药效持久。 结论 优化后的载胰岛素的季铵化壳聚糖纳米粒形态较好、粒径较小,为研究胰岛素的新型给药途径奠定了基础。     

胰岛素乳酸/羟基乙酸共聚物纳米粒的制备及口服药效学研究

目的探索可生物降解乳酸/羟基乙酸共聚物［poly(lactic-co-glycolic acid),PLGA］纳米粒作为大分子蛋白质类口服给药系统的可能性。方法用复乳溶剂挥发法制备了胰岛素乳酸/羟基乙酸共聚物纳米粒(INS-PLGA-NPs);光子相关光谱法测定了平均粒径;HPLC法测定了胰岛素的包封率;放射免疫法研究了纳米粒的载药方式;考察了INS-PLGA-NPs的体外释放特性;评价了口服给予纳米粒对糖尿病大鼠降血糖作用。结果以1% poloxamer 188为乳化剂制备的纳米粒,平均粒径为149.6 nm,多分散度为0.09,包封率为42.8%;同时抗体捕捉实验发现纳米粒主要以吸附方式载药;胰岛素的体外释放分为两相;以10 u·kg^-1的剂量给予该纳米粒,4 h后血糖浓度显著降低(P<0.05),10 h血糖降至最低,药理相对生物利用度(10.3±0.8)%。结论PLGA-NPs可能成为大分子蛋白质药物口服给药的新型载体。     

Pharmacokinetic study of triptolide, a constituent of immunosuppressive chinese herb medicine, in rats

Triptolide is a potential anti-immune agent, and has shown multi-organic toxicity, however its toxic mechanism remained undiscovered. This paper aimed at characterizing the pharmacokinetic profiles of triptolide in rats to provide the clue to approach the toxic mechanism. The absorption, distribution, metabolism and excretion of triptolide were investigated in male Sprague-Dawley rats after single doses of oral and i.v. administration. After oral administration of 0.6, 1.2 and 2.4 mg/kg, the concentration of triptolide in plasma reached the maximum within 15 min, and declined rapidly with an elimination half-life from 16.81 to 21.70 min. The triptolide kinetics was fitted into one-compartment model after i.v. administration. Oral absolute bioavailability was 72.08% at the dose of 0.6 mg/kg. Triptolide was also rapidly distributed and eliminated in all selected tissues. Less than 1% triptolide of the dose was recovered from the bile, urine or feces as parent drug within 48 h. While triptolide could not be detected in tissues and plasma at 4 h post dose, rats in the group C (oral: 1.2 mg/kg) and D (oral: 2.4 mg/kg) showed obvious toxic response to triptolide and some of rats even died out. It was indicated that triptolide was metabolized extensively, eliminated rapidly, and also showed that the toxicity produced by the triptolide was lag behind the exposure concentration.     

Studies on the cyclosporin A loaded stearic acid nanoparticles

Stearic acid nanoparticles were prepared in this study by melt-homogenization to investigate the possibility of them as a new kind of drug carrier system. Some physicochemical properties of stearic acid nanoparticles were studied and morphology examined by transmission electron microscope. Cyclosporin A as a model drug was then encapsulated into stearic acid nanoparticles. Following the establishment of high performance liquid chromatography assay for cyclosporin A analysis in stearic acid nanoparticles or blood samples, the encapsulation ratio of cyclosporin A to stearic acid nanoparticles was estimated and pharmacokinetics as well as bioavailability of cyclosporin A stearic acid nanoparticles after oral administration to Wistar rats were studied, using the Sandimmun Neoral® (an available microemulsion system of cyclosporin A) as a reference. The mean diameter of cyclosporin A stearic acid nanoparticles was 316.1 nm, while the encapsulation ratio of cyclosporin A to stearic acid nanoparticles reached to 88.36%. It was demonstrated by IR spectra and differential scanning calorimetry that there was no chemical reaction occurred between the cyclosporin A and stearic acid. The relative bioavailability of cyclosporin A stearic acid nanoparticles over reference was nearly 80%, and the time to reach maximum concentration (T_max) of cyclosporin A after oral administration of cyclosporin A stearic acid nanoparticles was delayed significantly than the reference, suggesting an obvious sustained release effect. The stearic acid nanoparticles might be a very potential drug carrier.     

Oral and subcutaneous absorption of insulin poly(isobutylcyanoacrylate) nanoparticles

Dispersions of insulin poly(isobutylcyanoacrylate) nanoparticles were obtained by anionic in situ polymerization using aqueous pluronic acid solution. Results showed a decrease in particle size diameter by increasing the pluronic acid concentration. Nanoparticles prepared in the presence of 2.5% pluronic acid resulted in particles of 85 nm average diameter and 59% intra-particular insulin load without the use of the oily core [Damge, C., Michel, M., Aprahamian, M., Couveur, P., 1988. New approach for oral administration with polycyanoacrylate nanocapsules as drug carrier. Diabetes 37, 246-251]. In vivo testing was performed on streptozocin induced diabetic rats. The subcutaneous injection of insulin nanoparticles was able to prolong its duration of hypoglycemic effect from 6 to 72 h. Effective oral absorption of the entrapped insulin was significantly better (p<0.01) when compared with non-encapsulated insulin or the control experiments.     

Toxicity Studies of Poly(Anhydride) Nanoparticles as Carriers for Oral Drug Delivery

Purpose

To evaluate the acute and subacute toxicity of poly(anhydride) nanoparticles as carriers for oral drug/antigen delivery.

Methods

Three types of poly(anhydride) nanoparticles were assayed: conventional (NP), nanoparticles containing 2-hydroxypropyl-β-cyclodextrin (NP-HPCD) and nanoparticles coated with poly(ethylene glycol) 6000 (PEG-NP). Nanoparticles were prepared by a desolvation method and characterized in terms of size, zeta potential and morphology. For in vivo oral studies, acute and sub-acute toxicity studies were performed in rats in accordance to the OECD 425 and 407 guidelines respectively. Finally, biodistribution studies were carried out after radiolabelling nanoparticles with ^99mtechnetium.

Results

Nanoparticle formulations displayed a homogeneous size of about 180 nm and a negative zeta potential. The LD₅₀ for all the nanoparticles tested was established to be higher than 2000 mg/kg bw. In the sub-chronic oral toxicity studies at two different doses (30 and 300 mg/kg bw), no evident signs of toxicity were found. Lastly, biodistribution studies demonstrated that these carriers remained in the gut with no evidences of particle translocation or distribution to other organs.

Conclusions

Poly(anhydride) nanoparticles (either conventional or modified with HPCD or PEG6000) showed no toxic effects, indicating that these carriers might be a safe strategy for oral delivery of therapeutics.     

Inhalable alginate nanoparticles as antitubercular drug carriers against experimental tuberculosis

Pharmacokinetic and chemotherapeutic studies have been carried out with aerosolised alginate nanoparticles encapsulating isoniazid (INH), rifampicin (RIF) and pyrazinamide (PZA). The nanoparticles were prepared by cation-induced gelification of alginate and were 235.5 +/- 0 nm in size, with drug encapsulation efficiencies of 70-90% for INH and PZA and 80-90% for RIF. The majority of particles (80.5%) were in the respirable range, with mass median aerodynamic diameter of 1.1 +/- 0.4 microm and geometric standard deviation of 1.71 +/- 0.1 microm. The relative bioavailabilities of all drugs encapsulated in alginate nanoparticles were significantly higher compared with oral free drugs. All drugs were detected in organs (lungs, liver and spleen) above the minimum inhibitory concentration until 15 days post nebulisation, whilst free drugs stayed up to day 1. The chemotherapeutic efficacy of three doses of drug-loaded alginate nanoparticles nebulised 15 days apart was comparable with 45 daily doses of oral free drugs. Thus, inhalable alginate nanoparticles can serve as an ideal carrier for the controlled release of antitubercular drugs.     

Pharmacokinetic variables of medium molecular weight cross linked chitosan nanoparticles to enhance the bioavailability of 5-fluorouracil and reduce the acute oral toxicity

To prepare glutaraldehyde-based cross-linked medium molecular weight chitosan nanoparticles encapsulated with 5-Fluorouracil (5-FU), to overcome dosing frequency as well as reducing acute oral toxicity and poor bioavailability of the drug. Medium molecular weight chitosan nanoparticles (MMWCH-NPs) were prepared by reverse micelles method based on glutaraldehyde (GA) cross-linking and optimized by the process as well as formulation variables like a various drug to polymer ratio, cross-linker volumes, varying stirring speeds (rpm), different time of rotation/stirring, respectively and their effects on the mean particles size distribution and entrapment efficiency %EE and %LC of NPs. Characterization of formulations was done by FTIR studies, TEM, PXRD, TGA, Stability, and dissolution drug release studies were performed by dialysis bag technique at both pH (1.2 & 7.4) and acute oral toxicity studies in albino rabbits. The formulated nanoparticles showed a smooth morphology with smaller particle size distribution (230–550 nm), zeta potential (−15 to −18 mV) required to achieve enhanced permeation and retention effect (EPR), entrapment efficiency (%EE 12–59%). These NPs exhibited a controlled drug release profile with 84.36% of the drug over a period of 24 h. Drug release data were fitted to different kinetic models which predominantly followed Fickian diffusion mechanism (R² = 0.972–0.976, N = 0.326–0.256). The optimized formulation (5-FU6) was observed under DSC/TGA, TEM. PXRD curves, FTIR, which confirmed thermal stability, structural integrity, amorphous state, compatibility between drug and polymer of optimized (5-FU6) as well as reduced acute oral toxicity in albino rabbits. Cross-linked medium molecular weight chitosan nanoparticles are nontoxic, well-tolerated therefore could be the future candidate for therapeutic effects as novel drug delivery carrier for anticancer drug(s).     

温敏在体凝胶给药系统的研究与应用

综述N-异丙基丙烯酰胺类聚合物、聚氧乙烯-聚氧丙烯共聚物、聚氧乙烯-聚乳酸羟基乙酸共聚物和多糖类衍生物等温敏聚合物的性质、特点、胶凝机制及在温敏在体凝胶给药系统中的应用进展。温敏在体凝胶作为一种智能水凝胶,可用作药物缓、控释和靶向输送的有效载体。     

Inhaled sildenafil nanocomposites: lung accumulation and pulmonary pharmacokinetics*

Context: Administration of sildenafil citrate (SC) is considered as a strategy in the treatment of pulmonary hypertension.

Objective: This study reports production of the inhalable microparticles containing SC-loaded poly(lactide-co-glycolic acid)-nanoparticles.

Methods: SC-nanoparticles were prepared by the double emulsion solvent evaporation method. Next, free SC and SC-loaded nanoparticles were spray dried in the presence of appropriate excipients (lactose, maltose and trehalose). Physicochemical properties and aerodynamic behavior of prepared powders were evaluated. In addition, drug accumulation from selected formulations in the rat lung tissue was compared with oral and IV administration.

Results: Size and fine particle fraction of selected nanocomposites and free SC microparticles were 7 and 4.5?µm, and 60.2% and 68.2%, respectively. Following oral and IV administration, the drug was not detectable in the lung after 4 and 6?h, respectively, but in SC-loaded nanoparticles, the drug was detectable in the lung even after 12?h of inhalation. Respirable particles containing free SC provided high concentration at first that was detectable up to 6 after insufflation.

Conclusion: In vivo study demonstrated that pulmonary administration of sildenafil and sildenafil nanoparticles produced longer half-life and higher concentration of the drug in the lung tissue as compared to oral and IV administration. So, these formulations could be more effective than oral and IV administration of this drug.