难溶性药物的增溶及其缓/控释制剂研究进展

目前由高通量药物筛选而得的活性物质约有40％是水难溶性的，难溶性药物（poorly water—soluble drug）因其在水中溶解度小，药物难以被机体吸收，体内消除速度较快，血药浓度容易出现峰谷现象，口服制剂生物利用度低，且难以实现剂型的多样化。已报道的增溶技术如固体分散技术、环糊精包合技术、胶束增溶、微乳增溶、超微粉碎等已用于增加难溶性药物的溶解度，提高其口服制剂的生物利用度。缓／控释制剂（sustained or controlled release dosage forms）具有减少用药总剂量和用药次数，避免血浓峰谷现象，降低毒副作用，提高病人顺应性等优点，在临床上的应用日益广泛。目前应用增溶技术和缓／控释技术提高难溶性药物的溶解度和生物利用度，研制难溶性药物的缓／控释制剂以成为药剂学研究的热点方向。本文就难溶性药物的增溶及其缓／控释制剂的研究进展做如下综述。     

液体制剂中难溶性药物的增溶

综述了液体制剂开发中难溶性药物的增溶方法,包括调节溶液pH值,应用表面活性剂,潜溶剂及包合等方法.     

难溶性药物增溶研究进展

如何增加难溶性药物的溶解度,改善其生物利用度,一直是药剂学研究的重要内容。该文就近年来应用广泛的纳米混悬剂、渗透泵、自微乳化技术、固体分散体、固体脂质纳米粒、液固压缩技术等一些新方法新技术在增加难溶性药物溶解度及改善生物利用度方面的应用进行综述。     

难溶性药物凝胶制剂研究进展

凝胶制剂作为透皮给药系统(transdermal drug delivery system,TDDS)的一种新型制剂,经皮肤给药发挥全身或局部治疗作用,有使用方便、安全性好、释药平缓持久等优势,成为近年来药物制剂研发的重点之一.但现有的大多数化合物均为难溶性药物,在凝胶制剂方面的应用受限.近年来,许多新型药物载体包括纳...     

提高难溶性药物口服生物利用度的方法

讨论了影响自胃肠道吸收药物生物利用度的因素，对提高难溶性药物口服生物利用度的方法进行了综述。     

应用纳米技术增加难溶性药物吸收的研究进展

随着高通量筛选等新技术的出现,涌现出许多难溶性的候选药物。利用纳米技术能减小难溶性药物的粒径,增加其溶解度、溶出度和口服生物利用度,减少食物效应的影响。本文介绍了纳米粒的制备方法,商用的专利纳米技术以及应用纳米技术成功上市的药品。纳米技术对改善生物药剂学分类体系（BCS）Ⅱ类药物的吸收具有广阔的前景。     

难溶性抗肿瘤药物注射剂的制剂研究

综述近几年来难溶性抗肿瘤药物注射剂的研究进展，分类介绍脂质体、混合胶束、微球和毫微粒、固体脂质纳米粒及IDD技术的特性和效用。     

纳米晶体技术在水难溶性药物口服制剂中应用的研究进展

目的综述水难溶性药物纳米晶体的制备方法,稳定剂在纳米晶体形成过程中的主要应用原理及产品物理性质的表征,为改善水难溶性药物溶解度或口服生物利用度提供理论依据。方法查阅国内外相关文献27篇,回顾纳米晶体技术的发展历程,提供药物纳米晶体技术的最新研究进展。结果药物纳米晶体不仅制备工艺简单,性质考察方便;还能够提高难溶性药物在胃肠道中的溶解度,改善难溶性药物的口服生物利用度。结论药物纳米晶体技术具有实际生产意义和广阔的应用前景。     

制剂增溶技术中高分子聚合物对难溶性药物释放性能的影响

目的 综述制剂增溶技术中高分子聚合物对难溶性药物释放度的影响,为实际应用提供参考。 方法 在查阅国内外相关文献的基础上,对制剂技术中高分子聚合物的加入对难溶性药物释放的影响进行分析和总结。 结果 高分子聚合物的类型、性质、药物在聚合物中的存在状态、结合方式以及聚合物与其他辅料的配伍等因素均能影响难溶性药物在制剂中的释放。 结论 高分子聚合物与难溶性药物从制剂中的释放有必然的联系。     

难溶性药物溶解度的提高方法

目的解决难溶药物溶解度问题。方法提高药物溶解度方法进行分析归纳。结果应用增溶剂、助溶剂、潜溶剂、包合、改变药物晶型,制备固体分散物、脂质体、纳米粒、微球、微乳、水溶性前体,调节溶液pH值等增加难溶性药物的溶解度。结论每种方法都各有长处,综合利弊合理选择。     

羟丙基-β-环糊精增溶难溶性药物研究进展

目的介绍羟丙基-β-环糊精增溶难溶性药物的研究进展。方法查阅近几年国内外文献报道，并进行分析归纳。结果新型辅料羟丙基-β-环糊精在药物制剂领域已有较普遍的应用和较深入的研究，其特性优良、安全性好、包合方法较多，近年来已广泛应用于难溶性药物的研究。结论开发和利用这一多功能新辅料，极有可能在药学领域获得突破性进展。     

Solubilizing Excipients in Oral and Injectable Formulations

A review of commercially available oral and injectable solution formulations reveals that the solubilizing excipients include water-soluble organic solvents (polyethylene glycol 300, polyethylene glycol 400, ethanol, propylene glycol, glycerin, N-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide), non-ionic surfactants (Cremophor EL, Cremophor RH 40, Cremophor RH 60, d-alpha-tocopherol polyethylene glycol 1000 succinate, polysorbate 20, polysorbate 80, Solutol HS 15, sorbitan monooleate, poloxamer 407, Labrafil M-1944CS, Labrafil M-2125CS, Labrasol, Gellucire 44/14, Softigen 767, and mono- and di-fatty acid esters of PEG 300, 400, or 1750), water-insoluble lipids (castor oil, corn oil, cottonseed oil, olive oil, peanut oil, peppermint oil, safflower oil, sesame oil, soybean oil, hydrogenated vegetable oils, hydrogenated soybean oil, and medium-chain triglycerides of coconut oil and palm seed oil), organic liquids/semi-solids (beeswax, d-alpha-tocopherol, oleic acid, medium-chain mono- and diglycerides), various cyclodextrins (alpha-cyclodextrin, beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin, and sulfobutylether-beta-cyclodextrin), and phospholipids (hydrogenated soy phosphatidylcholine, distearoylphosphatidylglycerol, L-alpha-dimyristoylphosphatidylcholine, L-alpha-dimyristoylphosphatidylglycerol). The chemical techniques to solubilize water-insoluble drugs for oral and injection administration include pH adjustment, cosolvents, complexation, microemulsions, self-emulsifying drug delivery systems, micelles, liposomes, and emulsions.     

Optimization of drug release from dermatological semisolid preparations

The aim of the present study was to optimize the process of drug release. Factors which influence drug release were studied in detail and their effects were described numerically. The factors studied were as follows: the concentration of the pharmacon (salicylic acid); its particle size; its suspended, dissolved, solubilized, or molecular encapsulated state;, the composition of the vehicle; the quantities of the polar and apolar components; and the viscosity of the vehicle. Drug release studies were carried out with Hanson's vertical diffusion cell. The process was described quantitatively by the slope of the equation describing the time‐course of the liberation, by the quantity of pharmacon liberated in 8 h and also by the optimization parameter determined on the basis of the 2² model of the factorial design method. Increase of the concentration of salicylic acid was found to be accompanied by an exponential rise in drug release, while the extent of liberation decreased linearly with increasing viscosity. The greatest increase in the optimization parameter was observed when the polarity of the vehicle was changed. The process of liberation consists of the following steps: dissolution of the pharmacon, diffusion of the dissolved molecules, and their distribution. The current data revealed that the distribution is the most important element and exerts the greatest influence on optimal drug release. Drug Dev. Res. 59:316–325, 2003. © 2003 Wiley‐Liss, Inc.     

Third-generation sequencing techniques and applications to drug discovery

Introduction: There is an immediate need for functional and molecular studies to decipher differences between disease and ‘normal’ settings to identify large quantities of validated targets with the highest therapeutic utilities. Furthermore, drug mechanism of action and biomarkers to predict drug efficacy and safety need to be identified for effective design of clinical trials, decreasing attrition rates, regulatory agency approval process and drug repositioning. By expanding the power of genetics and pharmacogenetics studies, next-generation nucleic acid sequencing technologies have started to play an important role in all stages of drug discovery.

Areas covered: This article reviews the first- and second-generation sequencing technologies (SGSTs) and challenges they pose to biomedicine. The article then focuses on the emerging third-generation sequencing technologies (TGSTs), their technological foundations and potential contributions to drug discovery.

Expert opinion: Despite the scientific and commercial success of SGSTs, the goal of rapid, comprehensive and unbiased sequencing of nucleic acids has not been achieved. TGSTs promise to increase sequencing throughput and read lengths, decrease costs, run times and error rates, eliminate biases inherent in SGSTs and offer capabilities beyond nucleic acid sequencing. Such changes will have positive impact on all sequencing applications to drug discovery.     

Third-generation sequencing techniques and applications to drug discovery

INTRODUCTION: There is an immediate need for functional and molecular studies to decipher differences between disease and 'normal' settings to identify large quantities of validated targets with the highest therapeutic utilities. Furthermore, drug mechanism of action and biomarkers to predict drug efficacy and safety need to be identified for effective design of clinical trials, decreasing attrition rates, regulatory agency approval process and drug repositioning. By expanding the power of genetics and pharmacogenetics studies, next-generation nucleic acid sequencing technologies have started to play an important role in all stages of drug discovery. AREAS COVERED: This article reviews the first- and second-generation sequencing technologies (SGSTs) and challenges they pose to biomedicine. The article then focuses on the emerging third-generation sequencing technologies (TGSTs), their technological foundations and potential contributions to drug discovery. EXPERT OPINION: Despite the scientific and commercial success of SGSTs, the goal of rapid, comprehensive and unbiased sequencing of nucleic acids has not been achieved. TGSTs promise to increase sequencing throughput and read lengths, decrease costs, run times and error rates, eliminate biases inherent in SGSTs and offer capabilities beyond nucleic acid sequencing. Such changes will have positive impact on all sequencing applications to drug discovery.     

Registries supporting new drug applications

Purpose

Knowledge of the benefits and risks of new drugs is incomplete at the time of marketing approval. Registries offer the possibility for additional, post‐approval, data collection. For all new drugs, which were approved in the European Union between 2007 and 2010, we reviewed the frequency, the type, and the reason for requiring a registry.

Methods

The European Public Assessment Reports, published on the website of the European Medicine Agency, were reviewed for drugs approved by the Committee for Medicinal Products for Human Use. We searched for key characteristics of these drugs, including therapeutic area (ATC1 level), level of innovation (the score is an algorithm based on availability of treatment and therapeutic effect), and procedural characteristics. In addition, we identified if these registries were defined by disease (disease registry) or exposure to a single drug (drug registry).

Results

Out of 116 new drugs approved in the predefined period, for 43 (37%), 1 to 6 registry studies were identified, with a total of 73 registries. Of these 46 were disease registries and 27 (single) drug registries. For 9 drugs, the registry was a specific obligation imposed by the regulators. The level of innovation and the orphan status of the drugs were determinants positively predicting post‐approval registries (OR 10.3 [95% CI 1.0‐103.9] and OR 2.8 [95% CI 1.0‐7.5], respectively).

Conclusions

The majority of registries required by regulators are existing disease registries. Registries are an important and frequently used tool for post‐approval data collection for orphan and innovative drugs.     

Microemulsions for oral administration and their therapeutic applications

Introduction: The microemulsion concept was introduced in 1943 by Hoar and Schulman. Self-microemulsifying drug delivery systems (S(M)EDDS) are much more recent and can be described as isotropic solutions of oils and surfactants that form oil-in-water O/W microemulsions when they are poured into an aqueous medium. When they are presented as soft capsules for oral delivery, S(M)EDDS have the ability to considerably improve the intestinal absorption of agents that are incorporated into the S(M)EDDS. Forty percent of newly discovered drug candidates have little or no water solubility and therefore have low and/or variable bioavailability profiles. Many of these drugs are good candidates for formulation into S(M)EDDS.

Areas covered: This paper describes the preparation and assessment of these formulations and their current applications. The characterisation of this type of formulation has improved, and in vitro models (Caco-2 cell cultures, Ussing chambers, the everted sac technique, etc.) can be used for screening different formulations. It describes also marketed formulations (i.e., cyclosporin and saquinavir S(M)EDDS) and some other formulations.

Expert opinion: Actual applications of S(M)EDDS remain rare. The first drug marketed as a S(M)EDDS was cyclosporin, and it had significantly improved bioavailability compared with the conventional solution. In the last decade, several S(M)EDDS loaded with antiviral drugs (e.g., ritonavir, saquinavir) were tested for treatment of HIV infection, but the relative improvement in clinical benefit was not significant. The S(M)EDDS formulation of Norvir® (soft capsules) has been withdrawn in some countries.     

生物技术药物口服微粒给药系统的研究进展

综合国内外相关文献报道．对生物技术药物口服微粒给药系统在胃肠道中的吸牧机制、所遇到的主要障碍、影响因素、提高生物利用度的策略以及常用生物技术药物口服微粒给药系统等进行综述，旨在为新型生物技术药物口服给药系统提供思路和方法。     

Pharmacosomes: the lipid-based new drug delivery system

Lipid-based drug delivery systems have been investigated in various studies and shown their potential in controlled and targeted drug delivery. Pharmacosomes are amphiphilic phospholipid complexes of drugs bearing active hydrogen that bind to phospholipids. Pharmacosomes impart better biopharmaceutical properties to the drug, resulting in improved bioavailability. Pharmacosomes have been prepared for various non-steroidal anti-inflammatory drugs, proteins, cardiovascular and antineoplastic drugs. Developing the pharmacosomes of the drugs has been found to improve the absorption and minimize the gastrointestinal toxicity. This article reviews the potential of pharmacosomes as a controlled and targeted drug delivery system and highlights the methods of preparation and characterization.