Rapidly disintegrating oramucosal drug delivery technologies

In addition to successfully delivering drugs to a specific site within the body, a goal of any drug delivery system is to improve patient compliance. Thus, rapidly disintegrating oramucosal drug delivery systems are the focus of extensive research due to their ability to rapidly and efficiently deliver drugs. These drug delivery systems are able to release the drug as soon as they come into contact with saliva, thus obliviating the need for water during administration which is an attribute that makes them highly attractive for patient groups such as infants, pediatrics and geriatrics. The significant physiological and anatomical structural features of the oral cavity, the rationale behind the formulation and use of rapidly disintegrating technologies for oramucosal drug delivery, and the technologies that are currently available on the market or that are still under various stages of development is also discussed in this review article. The various technologies are described in terms of their methods of formulation and known mechanisms of drug release. The challenges posed by accurate in vitro disintegration and dissolution testing of rapidly disintegrating drug delivery systems employing conventional and the most recent novel methodologies are also discussed, including the use of ex-vivo permeation studies and in vivo models.     

Advanced and controlled drug delivery systems in clinical disease management

Advanced and controlled drug delivery systems are important for clinical disease management. In this review the most important new systems which have reached clinical application are highlighted.Microbiologically controlled drug delivery is important for gastrointestinal diseases like ulcerative colitis and distally localized Crohn's disease. In cardiology the more classic controlled release systems have improved patient compliance and decreased side effects. In the treatment of intractable pain the spinal and transdermal route is well documented.In neurology the flattened peak-through levels of antiepileptic drugs and anti Parkinson's drugs represents a more predictable kinetic profile.Tracheal delivery of corticosteroids and sympaticomimetics in asthma and Chronic Obstructive Pulmonary Disease is fully accepted in clinical practice: delivery by this route results in better efficacy and a better safety profile.In gynaecology the delivery of pulsatile hormones (LHRH) is used for pregnancy induction, while transdermal oestrogens are promising in the prevention of osteoporosis.In surgical practice the use of antibiotic impregnated bone cement and antibiotic impregnated biodegradable collagens is well established.To prevent infections intravascular catheters coated with heparin or antibiotics are used.In ophthalmology the Ocusert^® systems provide a controlled release of different drugs in the eye.Most spectacular is the clinical introduction of the first liposomal drugs: amfotericine B and daunorubicine. Liposomal formulations of these drugs have enhanced activity and decreased toxicity compared to conventional formulations.     

自乳化药物传递系统的研究概况

目的:总结自乳化药物传递系统的研究概况.方法:对近期自乳化药物传递系统的形成机制、处方组成、体外质量评价及其在药剂学方面的应用进行介绍.结果与结论:自乳化药物传递系统对亲脂性和水难溶性的药物是一个非常有前景的新型载体系统.     

“Programmed Polymeric Devices” for Pulsed Drug Delivery

Pharmaceutical research strives to design drug delivery systems that respond to therapeutic needs. Considering the facts that physiologic parameters (e.g., heart rate, blood pressure, and plasma concentration of hormones, plasma proteins, and enzymes) display constancy over time, drug delivery systems with a constant release profile have been designed. However, because of circadian rhythms in physiologic parameters and pathologic conditions (e.g., asthma, angina pectoris), the conventional paradigm concerning drug concentrations "the flatter the better" may not be what the organism may need. Instead, to correlate with our biological needs, "precisely timed drug delivery," which could be accomplished with "programmable dosage forms," is required. Precisely timed drug delivery may maximize therapeutic efficacy, may minimize dose frequency, and may reduce toxicity by avoiding side effects and drug tolerance. This paper outlines the concepts that have been proposed to release drugs in a pulsed manner from pharmaceutical devices.     

皮肤给药的经皮吸收与测量技术研究进展

经皮给药系统（TDDS）可避免首关效应、胃肠道破坏，为新型皮肤给药系统，可通过控制释放而延长治疗效果，成为药物制剂开发研究的热点之一。但是，药物的理化性质以及皮肤屏障影响药物的经皮吸收。综述了TDDS常用的促渗透技术，包括化学、物理、纳米、天然促渗透技术；介绍了促渗透能力的测定方法，包括体外、离体和体内评估皮肤渗透性的方法。通过对经皮药物递送系统和经皮吸收能力测定方法的归纳与总结，以期为TDDS的合理使用和快速发展提供参考。     

Innovations in bioadhesive vaginal drug delivery system

Introduction: Vagina, due to its anatomical position and physiological characteristics is increasingly being explored as a site for drug delivery in recent years. This route coupled with bioadhesion phenomena has born fruitful results in delivering drugs both locally as well as systemically.

Areas covered: Bioadhesive vaginal drug delivery system has been used for the treatment of local diseases affecting the vagina like candidiasis, STD, vaginal dryness, and so on. Also, research has demonstrated that drugs can be successfully delivered to systemic circulation via vaginal mucosa for treatment of various diseases like migraine and osteoporosis. Besides, this vaginal route has also been used for uterine targeting of drugs. This review focuses on these recent innovations that have been patented in the area of bioadhesive vaginal drug delivery systems. The review also highlights certain physicochemical characteristics of bioadhesive polymers that affect drug delivery through this route.

Expert opinion: An in-depth study of this review will give an insight into the potential areas that can be explored while designing a bioadhesive vaginal drug delivery system. Also, the in vitro and in vivo experimental results discussed in the review will help stimulate research in development and optimization of newer formulations.     

微针经皮给药技术

微针是介于皮下注射和透皮贴剂之间的一种给药方式,利用在皮肤角质层产生的微小孔道来显著增加药物的经皮吸收。综述微针经皮给药技术的研究进展,介绍制造微针的材料和方法、微针的给药方式及其在经皮给药系统中的应用。     

微针透皮给药系统应用研究进展

微针透皮给药系统是近年来透皮给药系统研究的热点。微针透皮给药系统具有注射给药和透皮给药的双重优势,具有快速、方便、无痛等众多优点,研究表明可以显著提高药物透皮速率和吸收量,特别是在蛋白质、多肽、DNA和RNA等大分子物质的透皮制剂研究领域表现出良好的效果和应用前景,本文对微针透皮给药系统应用研究的最新进展进行了综述。随着微针加工技术、载药技术和应用研究的不断深入,微针透皮技术在临床领域将会有更广泛的应用。     

Ophthalmic drug delivery systems

New ophthalmic drug delivery systems are curently receiving increased attention, in part because of the expected emergence of new drugs with short biological half-lives whose usefulness may depend on a more continuous drug supply than eyedrops can provide, but also because of the potential of some delivery systems to reduce the side effects of the more potent drugs recently introduced or presently under investigation. Some ophthalmic delivery systems extend the duration of drug action by enhancement of corneal absorption; these systems include soluble gels and emulsions, hydrophilic ocular inserts, ion-pair associations, prodrugs, and liposomes. Since these systems enhance the “pulse entry” of the drug, they are limited to use with drugs whose dose-related side effects are not serious. Other delivery systems provide for a controlled release of drugs and therefore minimize the pulse entry with which side effects are associated. They can be based on any of several different mechanisms and include both erodible and nonerodible matrices. The various delivery systems that have recently been developed and those that are currently known to be under investigation are described in this paper, along with some observations regarding the future outlook of ophthalmic drug delivery systems.     

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。     

叶酸受体介导的靶向纳米给药系统研究进展

叶酸受体在许多恶性肿瘤细胞表面过度表达,而在正常细胞中则几乎不表达或只有少量表达。利用叶酸受体表达的特性,通过将叶酸修饰于药物载体表面,可使药物靶向输送至叶酸受体过度表达的肿瘤细胞中,从而避免对正常细胞产生毒性,提高药物疗效;而纳米给药系统因粒径较小等原因可使药物在肿瘤部位浓集。本文对近年来叶酸受体介导的靶向纳米给药系统进行了综述。     

Iontophoretic drug delivery using the IOMED Phoresor® system

Iontophoresis, or electromotive drug administration, is a process that enhances the delivery of drugs through a biological membrane via the application of low-intensity electrical current. This technology offers several advantages over oral and injection drug delivery. Key advantages of iontophoretic drug delivery include the avoidance of pain and potential for infection associated with needle injection, the ability to control the rate of drug delivery, the ability to programme the drug-delivery profile and the minimisation of local tissue trauma. Research using iontophoresis has shown delivery of a number of drug classes. By controlling the applied electric current one can tailor a dosage regimen with a drug delivery profile specific for an indication and the needs of the patient. Advances in iontophoretic electrode design, microelectronics and methods to optimise iontophoretic drug delivery have improved the ability to safely deliver both older, off-patent drugs, as well as new chemical entities being developed to treat a variety of diseases. In addition to transdermal applications, current research indicates that iontophoresis may prove to be a viable noninvasive drug delivery method for treating conditions that affect the back of the eye.     

经鼻脑靶向递药系统的研究进展

鼻腔与脑在解剖生理上的独特联系使得鼻腔给药作为脑内递药途径成为可能.鼻腔给药作为脑靶向的途径之一,可有效地使通过其他给药途径不易透过血脑屏障的药物绕过血脑屏障到达脑部,为中枢神经系统疾病的治疗提供了一种极有发展前景的脑内递药途径.就鼻腔给药脑靶向的依据、影响因素、评价方法、剂型等方面对经鼻脑靶向递药系统的研究现状进行总结.     

Effects of drug hydrophobicity on liposomal stability

A major obstacle in drug delivery is the inability to effectively deliver drugs to their intended biological target without deleterious side-effects. Delivery vehicles such as liposomes can minimize toxic side-effects by shielding the drug from reaction with unintended targets while in systemic circulation. Liposomes have the ability to accommodate both hydrophilic and hydrophobic drugs, either in the internal aqueous core or the lipid bilayer, respectively. In the present study, fluorescein and rhodamine have been used to model hydrophilic and hydrophobic drugs, respectively. We have compared the stabilities of liposomes encapsulating these fluorophores as a function of lipid content, time, and temperature. At 25 and 37 degrees C, liposomes containing distearoyl phosphatidylcholine as the major phospholipid component were found to be more stable over time than those containing dipalmitoyl phosphatidylcholine, regardless of the fluorophore encapsulated. Liposomes loaded with fluorescein were found to be more stable than those with rhodamine. Dipalmitoyl phosphatidylcholine liposomes that encapsulated rhodamine were the least stable. The results indicate that the physical properties of the drug cargo play a role in the stability, and hence drug delivery kinetics, of liposomal delivery systems, and desired drug release times can be achieved by adjusting/fine-tuning the lipid compositions.     

Potential and problems of developing transdermal patches for veterinary applications

A new frontier in the administration of therapeutic drugs to veterinary species is transdermal drug delivery. The primary challenge in developing these systems is rooted in the wide differences in skin structure and function seen in species ranging from cats to cows. The efficacy of a transdermal system is primarily dependent upon the barrier properties of the targeted species skin, as well as the ratio of the area of the transdermal patch to the species total body mass needed to achieve effective systemic drug concentrations. A drug must have sufficient lipid solubility to traverse the epidermal barrier to be considered for delivery for this route. A number of insecticides have been developed in liquid ‘pour-on’ formulations that illustrate the efficacy of this route of administration for veterinary species. The human transdermal fentanyl patch has been successfully used in cats and dogs for post-operative analgesia. The future development of transdermal drug delivery systems for veterinary species will be drug and species specific. With efficient experimental designs and available transdermal patch technology, there are no obvious hurdles to the development of effective systems in many veterinary species.     

Current strategies for targeted delivery of bio-active drug molecules in the treatment of brain tumor

Brain tumor is one of the most challenging diseases to treat. The major obstacle in the specific drug delivery to brain is blood–brain barrier (BBB). Mostly available anti-cancer drugs are large hydrophobic molecules which have limited permeability via BBB. Therefore, it is clear that the protective barriers confining the passage of the foreign particles into the brain are the main impediment for the brain drug delivery. Hence, the major challenge in drug development and delivery for the neurological diseases is to design non-invasive nanocarrier systems that can assist controlled and targeted drug delivery to the specific regions of the brain. In this review article, our major focus to treat brain tumor by study numerous strategies includes intracerebral implants, BBB disruption, intraventricular infusion, convection-enhanced delivery, intra-arterial drug delivery, intrathecal drug delivery, injection, catheters, pumps, microdialysis, RNA interference, antisense therapy, gene therapy, monoclonal/cationic antibodies conjugate, endogenous transporters, lipophilic analogues, prodrugs, efflux transporters, direct conjugation of antitumor drugs, direct targeting of liposomes, nanoparticles, solid–lipid nanoparticles, polymeric micelles, dendrimers and albumin-based drug carriers.     

Nanocarriers for cancer-targeted drug delivery

Nanoparticles as drug delivery system have received much attention in recent years, especially for cancer treatment. In addition to improving the pharmacokinetics of the loaded poorly soluble hydrophobic drugs by solubilizing them in the hydrophobic compartments, nanoparticles allowed cancer specific drug delivery by inherent passive targeting phenomena and adopted active targeting strategies. For this reason, nanoparticles-drug formulations are capable of enhancing the safety, pharmacokinetic profiles and bioavailability of the administered drugs leading to improved therapeutic efficacy compared to conventional therapy. The focus of this review is to provide an overview of various nanoparticle formulations in both research and clinical applications with a focus on various chemotherapeutic drug delivery systems for the treatment of cancer. The use of various nanoparticles, including liposomes, polymeric nanoparticles, dendrimers, magnetic and other inorganic nanoparticles for targeted drug delivery in cancer is detailed.     

制剂新技术在多肽、蛋白质类药物给药系统研究中的应用

目的 介绍制剂新技术在多肽、蛋白质类药物给药系统研究中的应用。方法 综述了多肽、蛋白质类药物的性质特点和影响其稳定性的原因;制剂新技术在多肽、蛋白质类药物给药系统中的运用;对LHRH及其类似物和胰岛素两类药物的新型制剂研究进行了概述。结果 脂质体、微乳和复乳、微球、纳米粒、自控式释药技术等制剂新技术广泛应用于多肽、蛋白质类药物给药系统中,取得了较大进展;黄体激素释放激素(LHRH)及其类似物和胰岛素两类药物的新剂型研究具有代表性且引人注目。结论 将制剂新技术用于多肽、蛋白质类药物给药系统的研究,有着广阔的应用前景。     

Stimuli-sensitive drug delivery systems for site-specific antibiotic release

Site-specific delivery of antibiotics has always been a high-priority area in pharmaceutical research. Conventionally used antibiotics suffer several limitations, such as low accumulation and penetration in diseased cells/tissues, limited bioavailability of drugs, drug resistance, and off-target toxicity. To overcome these limitations, several strategies have been exploited for delivering antibiotics to the site of infection, such as the use of stimuli-responsive antibiotic delivery systems, which can release antibiotics in a controlled and timely fashion. These stimuli can either be exogenous (light, magnetism, ultrasound, and electrical) or endogenous (pH, redox reactions, and enzymatic). In this review, we present a summary of recent developments in the field of stimuli-based targeted drug delivery systems for the site-specific release of antibiotics.     

眼部给药系统的研究进展

目的介绍眼部给药系统的研究进展。方法查阅总结近年来眼部给药系统的最新研究成果,展望其发展前景。结果胶粒给药系统使不同阶段眼部疾病的治疗成为可能;靶向给药使得药物能够透过各种屏障到达眼部病变部位;原位凝胶显著延长了药物在眼部的滞留时间;可降解植入剂避免了释药后的二次手术;眼部电离子渗透技术大大降低了眼部治疗的创伤。结论随着临床医学、药物制剂学、高分子材料学的发展及新技术的应用,眼部给药系统在眼部疾病治疗中的应用更加广泛,具有很好的发展前景。