盐酸洛拉曲克脂质体的制备及其质量考察

目的:制备盐酸洛拉曲克脂质体并考察其理化特性。方法:采用薄膜挤压-硫酸铵梯度法制备盐酸洛拉曲克脂质体,透射电镜及激光粒度分析仪分别观察和检测其粒径大小及分布,通过紫外分光光度法测定包封率及评估体外释药试验。结果:制备的盐酸洛拉曲克脂质体包封率达83.6%±2.37%,粒径103.5±26nm且分布均匀。24h体外释放实验结果提示约有66.5%的盐酸洛拉曲克从脂质体释放出来。结论:新制备的盐酸洛拉曲克脂质体粒径大小均匀,包封率尚有提高空间,具有体外缓慢释药的特性。     

盐酸洛拉曲克脂质体的制备及其质量考察

目的：制备盐酸洛拉曲克脂质体并考察其理化特性。方法：采用薄膜挤压-硫酸铵梯度法制备盐酸洛拉曲克脂质体,透射电镜及激光粒度分析仪分别观察和检测其粒径大小及分布,通过紫外分光光度法测定包封率及评估体外释药试验。结果：制备的盐酸洛拉曲克脂质体包封率达83.6%±2.37%,粒径103.5±26nm且分布均匀。24h体外释放实验结果提示约有66.5%的盐酸洛拉曲克从脂质体释放出来。结论：新制备的盐酸洛拉曲克脂质体粒径大小均匀,包封率尚有提高空间,具有体外缓慢释药的特性。     

多相脂质体人干扰素-α(HuIFN-α)包封率和渗漏的测定

脂质体是类脂双分子薄膜在一定条件下形成的超微球体。1971年Ryman等人将药物包入脂质体,研究了脂质体的载体作用,发现脂质体具有降低药物毒副作用,减少剂量和变态反应,增强药物对淋巴系统靶向性和靶组织滞留性等优点。干扰素-α为有效抗     

速效止泻胶囊含量测定方法的初步研究

目的：探讨速效止泻胶囊质量标准中含量测定方法的建立。方法：采用中性氧化铝柱层析-紫外分光光度法建立了盐酸小檗碱的含量测定方法。结果：线性关系r=0.99996,平均回收率为106．42％,含量限度为90mg/粒。结论：建立的含量测定方法准确可靠,可以控制产品质量。     

长循环紫杉醇纳米脂质体的合成及其活性评估

目的：研制甲氧基聚乙二醇二硬脂酰磷脂酰乙醇胺（mPEG2000-DSPE）修饰的长循环紫杉醇纳米脂质体（PEG-PTX-LP）,减少市售紫杉醇制剂的不良反应并增强疗效。方法：采用薄膜超声分散法制备PEG-PTX-LP,采用激光散射粒度分析仪和透射电镜观察其物理性状,超滤法检测药物包封率,透析法检测药物缓释能力,通过细胞摄取试验观察人脐静脉内皮细胞（Human Umbilical Vein Endothelial Cells,HUVEC）、A549肺癌细胞对PEG-PTX-LP的摄取能力。结果：透射电镜显示长循环紫杉醇纳米脂质体呈圆形囊泡样结构,粒径检测其平均粒径为99.1 nm,制备后第2、7、14、21、30天的紫杉醇包封率均大于99%,在血清中的缓释能力优于泰素溶液,HUVEC、A549细胞对PEG-PTX-LP中紫杉醇的摄取量明显高于泰素溶液（Taxol）。结论：采用mPEG2000-DSPE修饰的PEG-PTX-LP具有更高的稳定性和缓释能力,对肿瘤细胞和血管内皮细胞有一定的特异性,是一种更有效的紫杉醇新剂型。     

Entrapment of Peptidoglycans and Adamantyltripeptides into Liposomes: An HPLC Assay for Determination of Encapsulation Efficiency

Abstract

The encapsulation of different immunomodulating peptides, the peptidoglycan monomer, its semisynthetic derivatives (Adamant-1-yl)-acetyl-peptidoglycan monomer and Boc-Tyr-peptidoglycan monomer, respectively, and of two diastereoisomers of adamantyltripeptides into the large negatively charged multilamellar liposomes was investigated. The reproducible quantitative method using HPLC was established for the determination of the entrapped compounds. It was shown that the tested compounds could be efficiently incorporated into liposomes using either the film or modified film method. The results confirmed that the peptidoglycans with lipophilic substituents and particularly the adamantyltripeptides were incorporated into liposomes with higher efficiency than the peptidoglycan monomer using either of the described methods. Liposome preparations were stable at 4°C up to seven days as shown by minimal leaking of the entrapped material.     

Determination of protein absorption coefficients using a refractive index chromatographic monitor

Using lysozyme as a primary standard, a refractive index monitor designed for column chromatography was used to determined protein concentration and hence absorption coefficients. the method is non-destructive, requires only small amounts of protein 0.2 mg, and could be adapted for smaller samples.     

质粒纳米乳剂的制备与阴离子交换色谱测定方法

以纳米乳剂为载体包裹草原兔尾鼠卵透明带3DNA疫苗,制备获得了纳米乳剂DNA疫苗,并对其进行了质量评价。采用界面乳化法制备质粒纳米乳剂,用电子显微镜测定了其粒径及其分布,根据质粒的带电特性,利用强阴离子Q SepharoseTMXL色谱柱分离纳米乳剂和游离质粒,建立了强阴离子交换柱质粒纳米乳剂包封率的快速测定方法。结果表明:制备的纳米乳剂DNA疫苗的平均粒径为(23±10)nm,包封率为80.5%。选择0.05mol/L的Tris-HCl为平衡液,流速为0.7mL/min,紫外检测波长260nm,柱温30℃,进样量为2mL的实验条件,质粒的含量和峰面积的线性关系良好(r=0.9983),加样回收率在95%以上,该方法简便快速、灵敏度高,重复性好,可用于纳米乳剂DNA疫苗包封率的快速测定。     

Preparation and characterization of solid lipid nanoparticles loaded traditional Chinese medicine

Ultrasonication was employed to prepare solid lipid nanoparticles (SLN). The model traditional Chinese medicine, tetrandrine (TET), was incorporated into SLN. The TET–loaded SLN (TET–SLN) were spherical in the photograph of transmission electron microscope (TEM). The particle size measured by laser diffraction (LD) was found to be 157.3 ± 8.2 nm. Zeta potential analyzer suggested the zeta potential of TET–SLN was −29.36 ± 3.68 mV in distilled water. The entrapment efficiency (EE%) was determined with the sephadex gel chromatogram and high-performance liquid chromatogram (HPLC), and up to 90.59% of TET was incorporated. Stability evaluation showed relatively long-term stability with only slight particle growth (P > 0.05) after storage at room temperature for 4 weeks. Therefore, ultrasonication is demonstrated to be a simple, available and effective method to prepare high quality SLN loaded traditional Chinese medicine.     

The Study on the Entrapment Efficiency and In Vitro Release of Puerarin Submicron Emulsion

The entrapment efficiency (EE) and release in vitro are very important physicochemical characteristics of puerarin submicron emulsion (SME). In this paper, the performance of ultrafiltration (UF), ultracentrifugation (UC), and microdialysis (MD) for determining the EE of SME were evaluated, respectively. The release study in vitro of puerarin from SME was studied by using MD and pressure UF technology. The EE of SME was 86.5%, 72.8%, and 55.8% as determined by MD, UF, and UC, respectively. MD was not suitable for EE measurements of puerarin submicron oil droplet, which could only determine the total EE of submicron oil droplet and liposomes micelles, but it could be applied to determine the amount of free drug in SMEs. Although UC was the fastest and simplest to use, its results were the least reliable. UF was still the relatively accurate method for EE determination of puerarin SME. The release of puerarin SME could be evaluated by using MD and pressure UF, but MD seemed to be more suitable for the release study of puerarin emulsion. The drug release from puerarin SME at three drug concentrations was initially rapid, but reached a plateau value within 30 min. Drug release of puerarin from the SME occurred via burst release.     

Preparation, characterization and in vitro bioactivity of N-terminally PEGylated staphylokinase dimers

PEGylation can improve the therapeutic efficacy of proteins by increasing serum half-life of proteins and reducing immunogenicity and antigenicity. However, PEGylation results in a substantial loss of the bioactivity of proteins due to the steric hindrance of polyethylene glycol (PEG). Dimerization of the proteins is an efficient approach to increase the bioactivity of the PEG-protein conjugates. Here, staphylokinase (SAK) was used due to its therapeutic potential for coronary thrombolysis. SAK dimers (dSAK) were prepared by engineering cysteine residue at the C-terminus of SAK and dimerization of the cysteine residue with 1,4-bismaleimidobutane. PEG aldehyde was used for site-specific PEGylation of dSAK at one of its two N-termini. Structural analysis indicated that dimerization of SAK can decrease the steric hindrance of PEG and increase the binding affinity of PEG-SAK to plasminogen. Dimerization of SAK increased the relative bioactivity of PEG-SAK from 39.0% to 62.0%. Therefore, site-specifically PEGylated dSAK at one of its two N-termini has higher bioactivity than the N-terminal PEGylated SAK.