Synthesis and characterization of mannosylated pegylated polyethylenimine as a carrier for siRNA

Regulation of gene expression using small interfering RNA (siRNA) is a promising strategy for research and treatment of numerous diseases. In this study, we develop and characterize a delivery system for siRNA composed of polyethylenimine (PEI), polyethylene glycol (PEG), and mannose (Man). Cationic PEI complexes and compacts siRNA, PEG forms a hydrophilic layer outside of the polyplex for steric stabilization, and mannose serves as a cell binding ligand for macrophages. The PEI-PEG-mannose delivery system was constructed in two different ways. In the first approach, mannose and PEG chains are directly conjugated to the PEI backbone. In the second approach, mannose is conjugated to one end of the PEG chain and the other end of the PEG chain is conjugated to the PEI backbone. The PEI-PEG-mannose delivery systems were synthesized with 3.45-13.3 PEG chains and 4.7-3.0 mannose molecules per PEI. The PEI-PEG-Man-siRNA polyplexes displayed a coarse surface in Scanning Electron Microscopy (SEM) images. Polyplex sizes were found to range from 169 to 357 nm. Gel retardation assays showed that the PEI-PEG-mannose polymers are able to efficiently complex with siRNA at low N/P ratios. Confocal microscope images showed that the PEI-PEG-Man-siRNA polyplexes could enter cells and localized in the lysosomes at 2h post-incubation. Pegylation of the PEI reduced toxicity without any adverse reduction in knockdown efficiency relative to PEI alone. Mannosylation of the PEI-PEG could be carried out without any significant reduction in knockdown efficiency relative to PEI alone. Conjugating mannose to PEI via the PEG spacer generated superior toxicity and gene knockdown activity relative to conjugating mannose and PEG directly onto the PEI backbone.     

阿德福韦酯联合聚乙二醇干扰素α-2a治疗慢性乙型肝炎的疗效观察

目的：探讨阿德福韦酯联合聚乙二醇干扰素α-2a治疗慢性乙型肝炎的临床疗效。方法选取2012年1月至2014年1月门诊收治的慢性乙型肝炎患者80例,随机分为对照组和观察组各40例。对照组患者每周1次皮下注射180μg聚乙二醇干扰素α-2a;观察组在对照组基础上口服阿德福韦酯,10 mg/d。比较两组患者治疗后丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）以及乙型肝炎病毒（HBV）DNA、乙型肝炎e抗原（HBeAg）转阴率和HBeAg血清转换率。结果治疗后观察组患者ALT和AST显著低于对照组,差异有统计学意义（P〈0.01）,且观察组患者HBV DNA、HBeAg转阴率和HBeAg血清转换率均显著高于对照组,差异均有统计学意义（P＜0.05）。结论阿德福韦酯联合聚乙二醇干扰素α-2a治疗慢性乙型肝炎疗效显著,值得在临床推广应用。     

硝苯地平推拉式渗透泵片体外释放影响因素的研究

目的：本实验的目的是以难溶性药物硝苯地平为模型药物来研究推拉式渗透泵片剂中药物层和推动层的配方中聚合物聚氧乙烯的用量、氯化钠的用量、控释层包衣增重以及药物层和推动层的比例对药物释放的影响。方法：采用推拉式渗透泵设计,分别考察聚氧乙烯-N80在药物层中的不同用量、聚氧乙烯Coagulant在推动层中的不同用量以及氯化钠在推动层中不同用量的7个配方,7个配方片芯同时采用欧巴代CA包衣进行半透膜控释包衣,因片重大小不同,无法同时得到相同的包衣增重,所以结合实际包衣增重的数据,采用统计分析软件对包衣片在不同时间的药物释放数据进行建模分析。结果：统计结果表明欧巴代CA的包衣增重对药物释放有显著影响（P〈0.05）,随着包衣增重的增加,药物的释放变慢。聚氧乙烯N-80在药物层中的用量对药物释放也有显著影响（P〈0.05）,随着聚氧乙烯N-80在药物层中用量的增加,药物的释放变慢。而聚氧乙烯Coagulant和氯化钠在推动层的用量变化,在配方考察的比例范围内对药物的释放的影响不显著。对20小时的药物释放分析结果表明,药物层与推动层的比例对药物的后期释放有显著影响（P〈0.05）。药物层与推动层的比例越高,药物后期释放得越慢。     

Lipid based nanocarriers: a translational perspective

Over the recent couple of decades, pharmaceutical field has embarked most phenomenal noteworthy achievements in the field of medications as well as drug delivery. The rise of Nanotechnology in this field has reformed the existing drug delivery for targeting, diagnostic, remedial applications and patient monitoring. The convincing usage of nanotechnology in the conveyance of medications that prompts an extension of novel lipid-based nanocarriers and non-liposomal systems has been discussed. Present review deals with the late advances and updates in lipidic nanocarriers, their formulation strategies, challenging aspects, stability profile, clinical applications alongside commercially available products and products under clinical trials. This exploration may give a complete idea viewing the lipid based nanocarriers as a promising choice for the formulation of pharmaceutical products, the challenges looked by the translational process of lipid-based nanocarriers and the combating methodologies to guarantee the headway of these nanocarriers from bench to bedside.     

人工模拟干旱胁迫下金银花幼苗的生理适应性反应

目的研究人工模拟干旱胁迫条件下金银花幼苗的生理适应性反应,为揭示金银花植株的抗旱机制以及抗旱品种的选育提供理论依据。方法采用聚乙二醇（PEG-6000）模拟干旱胁迫处理金银花幼苗,检测幼苗体内的丙二醛（MDA）含量;超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）等保护酶活性,渗透调节物质脯氨酸（Pro）和可溶性糖含量。结果 10%、20%和30%PEG处理幼苗后120 h MDA含量分别高出对照组20.31%、28.12%和36.72%,随着PEG浓度升高,MDA含量逐渐增加。SOD、POD、CAT和APX活性总体呈现先升高后降低的趋势,各种酶对干旱胁迫的响应速率不同,CAT于干旱胁迫后立即开始启动,SOD、POD于干旱胁迫后24 h启动,而APX于干旱胁迫后48 h开始启动。Pro和可溶性糖含量均于处理后24 h开始增高,于处理后72 h达到峰值。结论随着干旱程度的增加和胁迫的延长,金银花体内膜质过氧化严重,通过增加Pro、可溶性糖的含量以及保护酶系统来抵御干旱胁迫,保护酶启动顺序为CAT、SOD、POD、APX。     

Improvement of Oral Bioavailability and Anti-Tumor Effect of Zingerone Self-Microemulsion Drug Delivery System

This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration （IC50）of Z-SMEDDS and free zingerone was 8.45 μg/mL and 13.30 μg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.     

复方聚乙二醇电解质散联合甘油灌肠剂用于妇科恶性肿瘤肠道准备临床观察

目的：观察复方聚乙二醇电解质散联合甘油灌肠剂在妇科恶性肿瘤术前肠道准备中的临床效果。方法32例接受妇科恶性肿瘤手术的患者,于手术前口服复方聚乙二醇电解质散溶液,联合甘油灌肠剂灌肠,观察患者不良反应、肠管状况、术后肛门排气时间评估肠道准备效果。结果复方聚乙二醇电解质散联合甘油灌肠剂用于妇科恶性肿瘤术前肠道准备具有好的临床效果,且副反应少。结论复方聚乙二醇电解质散联合甘油灌肠剂用于妇科恶性肿瘤术前肠道准备,方法简单,安全,有效,患者痛苦小。     

The Effect of PEG Concentration on the Release Rate of Cisplatin from PEG-Modified Silica Xerogels

Cisplatin—an antineoplastic medicine—was incorporated into a polyethylene glycol (PEG)-modified silica xerogels received by the sol-gel method. The influence of PEG concentration and drying temperature on the release of cisplatin was studied. From our results we may state that addition of PEG (M_W 600) and drying of silica xerogels at 80 °C augmented the release of cisplatin. The release of cisplatin from the matrices grows with the increase of PEG volume in xerogel (up to 74–97% within 7 days), whereas application of thermal drying resulted in both increased speed and amount of the drug released up to 91–97% within 2 days.     

Polyethylene glycol (PEG): a versatile polymer for pharmaceutical applications

ABSTRACT

Introduction: Polyethylene glycol (PEG) is a polymer of choice in drug delivery systems. This USFDA-approved polymer is popular due to its tunable properties and well-established safety profile: prime requisites considered during the selection of any excipient in formulation development.

Areas covered: The unique properties and applications of PEG have been discussed at length in the existing literature. However, a proper guidance on selection of PEG grade to cater to one’s purpose is lacking. This article provides preliminary guidelines to formulators on selection of appropriate PEG grade, typically based on its physico-chemical properties and role-based functional application in pharmaceuticals. It should be noted that the aim article is not to deep dive in each application area.

Expert opinion: Guidance on PEG application and grade of choice is lacking in the available literature. The authors have discussed and provided guidance to formulators on the appropriate PEG grade selection for particular application based on the available in vitro and in vivo literature data. In this review a State-of-the-art use of PEG in therapeutic applications, its clinical status and commercial use is also summarized. Nevertheless, toxicities related to different PEG grades and related impurities are discussed in this review.     

Influence of Type and Level of Water-Soluble Additives on Drug Release and Surface and Mechanical Properties of Surelease® Films

Ethylcellulose in combination with water-soluble additives has been used in the development of microporous membrane-coated dosage forms. In the present study, application of three types of water-soluble additives, namely polyethylene glycols (PEG 400, 3350, and 8000), maltodextrins (Maltrin M150, M100, and M040 in the order of lower to higher average polymer size and molecular weight; dextrose equivalence 16.9, 11.1, and 4.8, respectively), and xylitol, as porosity modifiers in the films of a commercially available aqueous ethylcellulose dispersion (Surelease/E-7-7060 plasticized with glyceryl tricaprylate/caprate) was investigated. The effect of type and level of these additives on drug release characteristics and surface and mechanical properties of the polymeric films was studied. Each additive was incorporated at 20 and 30% levels in the polymeric dispersion based on its solids content. Ibuprofen tablets were coated using the polymeric dispersion with and without additive at 3% w/w coat level in a fluid-bed equipment. The coated tablets were evaluated for their drug release rate, coat reflectivity (gloss), Brinell hardness, and elastic modulus. Differential scanning calorimetric analysis of the films was performed to determine the physico-chemical changes in the applied film-coats. The rate of drug release, hence film porosity, was observed to be dependent on the type and level of the additive added. The molecular weight of the additive and its concentration in the polymeric dispersion had significant influence on the rate of drug release, hardness, and elasticity of the film-coats.