纳米混悬剂研究进展

纳米混悬剂作为一种中间剂型,可以进一步制备为适合口服、注射或其他给药途径的药物剂型,从而提高药物的吸收和生物利用度.纳米混悬剂能提高制剂中药物的含量,特别适合大剂量、难溶性药物的口服和注射给药.本文综述纳米混悬剂的特点、制备方法、理化性质及其应用.     

纳米晶体技术在肺吸入给药中的研究进展

肺吸入给药是可实现肺靶向或全身给药的理想给药途径。然而肺部结构特征的复杂性给开发肺吸入制剂研发带来了困难,纳米晶体技术为解决难溶性药物肺部给药提供了一种有效的方法,其粒径小,可克服肺部中存在的生理屏障,提高药物的生物利用度,近年来引起了药物制剂学家的广泛关注。本文围绕肺部给药的屏障及纳米晶体在肺吸入给药的应用展开综述,期望为促进难溶性药物肺部给药提供借鉴。     

纳米晶体技术及其靶向递药应用研究进展

纳米晶体混悬液是药物纳米胶态分散体系,其制备工艺简单、载药量较高、稳定性好,若对药物纳米晶体进行粒径控制或表面修饰还可以靶向某些特定部位,如肝、脾、脑或肿瘤等组织,为改善难溶性药物的溶出度以及体内靶向分布提供了新的方法。本文重点围绕纳米晶体的靶向给药应用以及影响纳米晶体靶向性能的关键影响因素方面展开综述,期望为纳米晶体制剂技术的发展提供借鉴与思考。     

纳米给药系统在难溶性药物制剂研究中的应用

近年来,难溶性药物给药系统一直是制剂学研究的重点和难点之一。纳米载体由于其良好的生物相容性及可装载大量难溶性药物等特点而被广泛应用于难溶性药物给药系统的研究,该类载体主要包括纳米粒、脂质体、纳米乳、聚合物胶束、纳米混悬剂等。本文结合近几年国内外文献报道,对纳米给药系统在难溶性药物制剂研究中的最新进展进行概述。     

环糊精纳米给药系统在药物传递中的应用

目的对目前环糊精纳米给药系统的应用进行综述。方法参考近年来国内外文献共28篇,根据纳米制剂形成的驱动力不同将常见的环糊精纳米制剂分为四类进行分类和评述。结果基于环糊精的纳米给药系统综合应用环糊精包合技术和纳米技术共同改善药物的性质。根据形成纳米制剂的驱动力不同,主要分为四类:主分子—客分子介导的环糊精纳米载体、两亲性环糊精衍生物纳米粒、基于环糊精的聚合物纳米粒、无机环糊精纳米粒。同时介绍了环糊精纳米制剂的药剂学应用、研究进展以及发展前景。结论 环糊精纳米给药系统不仅能解决纳米粒载药量过低的缺点,还能达到靶向性,显著提高难溶性药物的生物利用度,极具发展前景和应用价值。     

纳米混悬液的制备方法及其在药物输送中应用的研究进展

纳米混悬液系采用少量表面活性剂或其它载体等稳定纯药物粒子所形成的一种亚微米胶体分散体系。纳米混悬液可增大难溶性药物的溶解度,提高药物的有效性和安全性等。通过查阅国内外相关文献,文章就纳米混悬液的制备方法、评价方法及在药物输送中的应用进行了综述。纳米混悬液的制备技术主要有两种,即Bottom up技术和Top down技术。其评价方法主要包括:粒径及粒径分布、Zeta电势、药物晶体状态等。纳米混悬液在各种给药途径中均有优势。纳米混悬液做为一种新型的药物载体有着广阔的研究前景     

纳米药物晶体的制备技术研究进展

纳米药物晶体可解决多数难溶性药物的溶解度和溶出度问题,近年来成为难溶性药物给药系统研究的热点之一.本文着重综述了纳米药物晶体的制备技术,如沉淀法、分散法、乳化法和微乳化法、超临界流体结晶法等的研究进展.     

纳米结构脂质载体用于肺靶向递送体系研究进展

目的 为肺部疾病的治疗和难溶性药物替代制剂的研发提供参考。方法 总结纳米结构脂质载体（NLC）的基本类型、制备方法及在肺部疾病治疗中应用的研究进展,并探讨其提高肺部相关疾病治疗有效性和安全性的效果。结果 NLC包括无定型、不完全晶体型、多重结构型3种形态,制备方法包括高压均质法、溶剂分散法、熔融乳化-超声法、乳微法等;NLC可使药物活性成分更易被包载,储存中药物外泄减少,物理稳定性更好,能控制药物靶向释放,提高难溶性药物的饱和溶解度;一定程度上降低给药频率,减少给药剂量和减弱不良反应。结论 NLC为基于脂质纳米粒上开发的一种新型药物传递系统,其载体药物经肺部吸入给药,特别适用于肺部疾病的治疗,是口服和静脉给药途径较有潜力的替代方案。     

纳米载体提高难溶性药物口服生物利用度的研究进展

纳米载体是药剂学备受关注的研究领域,作为一类新型给药系统,它能显著提高难溶性药物的溶解度、生物利用度和稳定性,且具有明显的缓释作用,因此得到了广泛的应用。目前常用于提高难溶性药物口服生物利用度的纳米载体有纳米脂质体、固体脂质纳米粒、纳米胶束、和纳米结晶等,它们的粒径、表面性质及其释药环境等是影响纳米载体药物口服吸收的主要因素。本文对纳米载体提高难溶性药物口服生物利用度的研究进展作一综述。     

基于纳米载药技术的丹参难溶性成分在抗肿瘤治疗中的研究进展

丹参难溶性成分因能对抗多种恶性肿瘤而成为很好的抗肿瘤候选药物,但因其水溶性差、半衰期短、生物利用度低,极大限制了其临床应用。随着纳米技术的持续发展,基于纳米粒、脂质体、聚合物胶束等中药纳米给药系统能够很好地克服这些不足并被开发应用于临床。本文对近年报道的丹参难溶性成分纳米给药系统在抗肿瘤治疗中的研究进展进行综述,以期为今后进一步开发丹参难溶性成分的纳米给药系统提供理论依据。     

Drug delivery via the buccal mucosa

A candidate drug has entered the development phase but there are problems in drug delivery. The oral bioavailability is low or provides the wrong plasma profile. It is usual that other routes of administration are proposed such as nasal, pulmonary, transdermal, buccal or rectal drug delivery. These routes offer advantages but they also require some development time. The situation regarding patents has to be examined, specific formulations must be manufactured—which can require a large amount of the active drug—and sometimes new excipients are used and these have to be documented, and other animal species may need to be chosen for appropriate evaluation. The buccal mucosa is one of the administration sites that might provide an alternative for peroral administration. This review will provide an insight into this route of drug delivery and the formulations that are, or can be, used, and it will also describe the challenges or possibilities of this route of administration.     

Drug nanosuspensions: a ZIP tool between traditional and innovative pharmaceutical formulations

Introduction: A nanosuspension or nanocrystal suspension is a versatile formulation combining conventional and innovative features. It comprises 100% pure drug nanoparticles with sizes in the nano-scale range, generally stabilized by surfactants or polymers. Nanosuspensions are usually obtained in liquid media with bottom-up and top-down methods or by their combination. They have been designed to enhance the solubility, the dissolution rate and the bioavailability of drugs via various administration routes. Due to their small sizes, nanosuspensions can be also considered a drug delivery nanotechnology for the preparation of nanomedicine products.

Areas covered: This review focuses on the state of the art of the nanocrystal-based formulation. It describes theory characteristics, design parameters, preparation methods, stability issues, as well as specific in vivo applications. Innovative strategies proposed to obtain nanomedicine formulation using nanocrystals are also reported.

Expert opinion: Many drug nanodelivery systems have been developed to increase the bioavailability of drugs and to decrease adverse side effects, but few can be industrially manufactured. Nanocrystals can close this gap by combining traditional and innovative drug formulations. Indeed, they can be used in many pharmaceutical dosage forms as such, or developed as new nano-scaled products. Engineered surface nanocrystals have recently been proposed as a dual strategy for stability enhancement and targeting delivery of nanocrystals.     

纳米粒形状对体内药动学的影响及非球形纳米粒制备方法的研究进展

目的介绍非球形纳米粒的最新研究进展,并对其体内药动学行为及制备方法进行综述。方法参考近年来国内外的23篇文献,根据纳米粒形状对体内药动学影响及非球形纳米粒的制备方法分类并总结。结果形状这一影响因素同聚合物种类、颗粒大小和表面化学等一样影响着纳米粒子在体内的吞噬、转运、吸附等药动学行为,因此,可以根据需要将纳米粒设计成不同形状以达到缓释、靶向等作用;可以采用"PRINT"技术、介孔硅技术、膜拉伸技术等或联合应用多种技术制备非球形纳米粒;可以根据要求的不同,把制备的非球形纳米粒制成注射剂、肺部吸入剂及口服制剂等等。结论纳米粒的形状对体内药动学有着重要影响,并且逐渐受到越来越多的关注,制备非球形纳米粒的方法也在不断地涌现。在今后的研究中,仍需开发大规模且高效生产非球形纳米粒的方法,以及对粒子形状在生物学相关领域的影响上做系统性的研究,使非球形纳米粒在药物传递领域中发挥重要的作用。     

The development and registration of topical pharmaceuticals

From our own experience we have seen that over the past 60 years topical delivery of drugs with its advantages and disadvantages has become much more widely understood and much more is now known about the disposition of drugs in the skin. Today, pharmaceutical scientists produce dermatological vehicles which are tailored to patients' needs and better appreciate how the formulation may affect rates of drug delivery, and ultimately, efficacy and safety. The guidelines for developing a New Chemical Entity (NCE) to be administered by the topical route are rather straightforward. What appears to be less well understood are the pathways for development, and the regulatory routes for topical formulations of a known established Active Pharmaceutical Ingredient (API) either in a new formulation, at a different concentration, or with APIs where topical administration is an alternative route of administration. This article provides guidance, on the regulatory routes which can help achieve marketing approval in Europe for topical formulations, with particular emphasis on clinical development. Some comments on NCE's will be given, and further detail is provided in cases where the topical route is a new method of administration for delivering a known API.     

PLGA nanoparticles in drug delivery: the state of the art

Nanoparticles represent drug delivery systems suitable for most administration routes. Over the years, a variety of natural and synthetic polymers have been explored for the preparation of nanoparticles, of which Poly(lactic acid) (PLA), Poly(glycolic acid) (PGA), and their copolymers (PLGA) have been extensively investigated because of their biocompatibility and biodegradability. Nanoparticles act as potential carries for several classes of drugs such as anticancer agents, antihypertensive agents, immunomodulators, and hormones; and macromolecules such as nucleic acids, proteins, peptides, and antibodies. The options available for preparation have increased with advances in traditional methods, and many novel techniques for preparation of drug-loaded nanoparticles are being developed and refined. The various methods used for preparation of nanoparticles with their advantages and limitations have been discussed. The crux of the problem is the stability of nanoparticles after preparation, which is being addressed by freeze-drying using different classes of lyoprotectants. Nanoparticles can be designed for the site-specific delivery of drugs. The targeting capability of nanoparticles is influenced by particle size, surface charge, surface modification, and hydrophobicity. Finally, the performance of nanoparticles in vivo is influenced by morphological characteristics, surface chemistry, and molecular weight. Careful design of these delivery systems with respect to target and route of administration may solve some of the problems faced by new classes of active molecules.     

Non-invasive Systemic Drug Delivery: Developability Considerations for Alternate Routes of Administration

Over the past few decades alternate routes of administration have gained significant momentum and attention, to complement approved drug products, or enable those that cannot be delivered by the oral or parenteral route. Intranasal, buccal/sublingual, pulmonary, and transdermal routes being the most promising non-invasive systemic delivery options. Considering alternate routes of administration early in the development process may be useful to enable new molecular entities (NME) that have deficiencies (extensive first-pass metabolism, unfavorable physicochemical properties, gastro-intestinal adverse effects) or suboptimal pharmacokinetic profiles that are identified in preclinical studies. This review article describes the various delivery considerations and extraneous factors in developing a strategy to pursue an alternate route of administration for systemic delivery. The various delivery route options are outlined with their pros and cons; key criteria and physicochemical attributes that would make a drug a suitable candidate are discussed; approaches to assess delivery feasibility, toxicity at the site of delivery, and overall developability potential are described; and lastly, product trends and their disease implications are highlighted to underscore treatment precedence that help to build scientific rationale for the pursuit of an alternate route of administration. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:1–20, 2010     

Transdermal delivery of contraceptives

Contraceptive agents are administered to the body through a variety of routes. Research has recently been directed at examining the transdermal route for systemic delivery of contraceptive agents, including estrogens and progestins. The transdermal route has several potential advantages over the other routes of administration: (1) improved compliance, (2) once-weekly administration, (3) delivery is easily terminated, and (4) some side effects can be alleviated based on more constant delivery rates. This article reviews the permeability of skin toward contraceptive steroids and how skin permeability is evaluated. The metabolism of contraceptive steroids is also considered. Transdermal delivery systems used to deliver contraceptives are presented, followed by a detailed discussion of several delivery systems for specific contraceptive agents such as levonorgestrel and estradiol. The potential problem of skin irritation is presented as it relates to transdermal contraceptive delivery systems, all of which will be worn chronically.     

Chitosan formulations as carriers for therapeutic proteins

Protein drugs represent a significant part of the new pharmaceuticals coming on the market every year and are now widely spread in therapy to treat or relief symptomatology related to many metabolic and oncologic diseases. The delivery of therapeutic proteins is still a major drawback against their maximum pharmacodynamic due to their physicochemical properties, poor stability, permeability and biodistribution. Despite the fact that the parenteral route remains the primary route of protein administration, research continues on non-parenteral delivery routes. However, the high molecular weight of proteins, combined with their hydrophilic and charged nature, renders transport through membranes very difficult. In this regard, the biopolymer chitosan exhibits several favorable biological properties, such as biocompatibility, biodegradability, low-toxicity and mucoadhesiveness, which made it a promising candidate for the formulation of protein drugs. The success of a protein formulation depends not only on the stability of the delivery system but also on their ability to maintain the native structure and activity of the protein during preparation and the delivery, as well as during long-term storage of the formulation. Chitosan-based delivery systems have been proposed as valid approaches to provide such protective conditions. The development of novel protein delivery systems based on chitosan is a rising subject irrespective of the intended route of administration. In this review, the different approaches recently exploited to formulate and deliver therapeutic proteins are underlined.     

Bioavailability and pharmacokinetics of lorazepam after intranasal, intravenous, and intramuscular administration.

The purpose of this study was to evaluate the pharmacokinetic profile of intranasal lorazepam in comparison to currently established administration routes. Eleven healthy volunteers completed this randomized crossover study. On three occasions, each separated by a 1-week washout, subjects received a 2 mg dose of lorazepam via the intranasal, intravenous, or intramuscular route. Blood samples were collected serially from 0 to 36 hours. Noncompartmental methods were used to determine pharmacokinetic parameters. Lorazepam was well absorbed following intranasal administration with a mean (%CV) bioavailability of 77.7(11.1). Intranasal administration resulted in a faster absorption rate than intramuscular administration. Elimination profiles were comparable between all three routes. The concentration-time profile for intranasal delivery demonstrated evidence of a double peak in several subjects, suggesting partial oral absorption. Females were found to have significantly higher AUC values than males for all three delivery routes. Overall, this study demonstrated favorable pharmacokinetics of intranasal lorazepam in relation to standard administration methods. Intranasal delivery could provide an alternative, noninvasive delivery route for lorazepam.