不同剂型青藤碱的体外皮肤渗透性

目的:比较青藤碱微乳、固体脂质纳米粒和脂质体对离体大鼠皮肤的透皮能力。方法:采用改进的Franz扩散池研究三者的透皮行为,采用高效液相色谱法测定接受液中青藤碱浓度并比较三者的经皮渗透能力。结果:t检验结果表明,体外经皮渗透试验中,青藤碱不同剂型的经皮渗透速率差异明显,差异具统计学意义(P<0.01),微乳>固体脂质纳米粒>脂质体。结论:青藤碱微乳有较强的透皮能力,适合青藤碱的新型透皮给药剂型。     

Colloidal carriers for the enhanced delivery through the skin

Background: The skin is the largest organ of our body and acts as a protective barrier with sensory and immunological functions. Its peculiar structure influences the passage of bioactives and only its modulation can facilitate the drug dermal/transdermal diffusion. In the past few years research in this field has assured better use of this application area. Methods: One of the most promising approaches is the use of drug delivery devices; this review explains the state of the art of drug transport through the skin by means of vesicular (classic liposomes, Transfersomes, niosomes and ethosomes) and particulate systems. Results/conclusion: Colloidal drug delivery systems are important in the field of drug delivery systems as their different characteristics make them suitable for various purposes.     

Alginate-based sustained release drug delivery systems for tuberculosis

Drug delivery systems have wide biomedical applications owing to their distinct therapeutic advantages, such as controlled release of drugs over prolonged periods, protection against premature drug degradation, reduction in drug toxicity and drug–drug interactions. All these factors are important considerations in the treatment of chronic infectious diseases such as tuberculosis. In tuberculosis, patient non-compliance is a vexing problem which is responsible not only for treatment failure, but also for the emergence of multi-drug resistant cases. Alginate, a natural polymer, has attracted researchers owing to its ease of availability, compatibility with hydrophobic as well as hydrophilic molecules, biodegradability under physiological conditions, lack of toxicity and the ability to confer sustained release potential. It is not therefore surprising that the controlled release phenomenon of this polymer has been documented for a vast array of drugs. In particular, the ability of alginate to co-encapsulate multiple antitubercular drugs and offer a controlled release profile is likely to have a major impact in enhancing patient compliance for better management of tuberculosis.     

Current advances in sustained-release systems for parenteral drug delivery

Major progresses in the development of parenteral sustained-release systems have been made in recent years as evidenced by the regulatory approval and market launch of several new products. Both the availability of novel carrier materials and the advances in method of fabrication have contributed to these commercial successes. With the formulation challenges associated with biologics, new delivery systems have also been evolved specifically to address the unmet needs in the parenteral sustained release of proteins. In this review paper, different new carriers systems and preparation methods are discussed with special focus on their applications to biologicals.     

Clinical experience with drug delivery systems as tools to decrease the toxicity of anticancer chemotherapeutic agents

Introduction: The toxicity of chemotherapeutic agents, resulting from their low pharmacological index, introduces considerable discomfort and risk to cancer patients. Among several strategies to reduce the toxicity of chemotherapeutic agents, targeted drug delivery is the most promising one.

Areas covered: Liposomes, micelles, albumin-based, polymeric, dendritic and lipid core nanoparticles have been used as carriers to concentrate anticancer drugs in neoplastic tissues, and clinical studies of those preparations are reviewed. In most clinical studies, drug delivery systems reduced drug toxicity. Lipid core nanoparticles (LDE) that bind to cell lipoprotein receptors have the ability to concentrate in neoplastic tissues and were the first artificial non-liposomal system shown in in vivo studies to possess targeting properties. The toxicity reduction achieved by LDE as vehicle of carmustine, etoposide and paclitaxel was singularly strong.

Expert opinion: The reduced toxicity offered by drug delivery systems has expanded treatment population that may benefit from chemotherapy including feeble, overtreated and elderly patients that would otherwise be offered palliative therapy. Drug delivery systems may either prolong the duration of treatments or allow increases in drug dose.     

Chemical and technological delivery systems for idebenone: a review of literature production

Introduction: Idebenone (IDE) is an antioxidant compound, structurally related to coenzyme Q10. Its therapeutic potential is growing in different application areas, as demonstrated by the number of experimental works and patents produced in very recent years.

Areas covered: Cyclodextrin inclusion complexes, liposomes, microemulsions, prodrugs, polymeric and lipid nanoparticles have been explored to achieve different goals, such as topical administration, brain targeting or increasing the bioavailability of this highly lipophilic drug. This review summarizes the results of works published in the last 20 years for the delivery and targeting of this drug.

Expert opinion: A direct comparison of the different carrier systems is not easy and could not even be significant, due to the large variables existing among them. However, the different forms of delivery can help increase idebenone solubility, stability and biochemical activity. Further studies will be developed in order to improve the controlled release and targeting of idebenone.     

Solid lipid nanoparticles as a drug delivery system for the treatment of neurodegenerative diseases

ABSTRACT

Introduction: The failure of many molecules as CNS bioactive compounds is due to many restrictions: poor water solubility, intestinal absorption, in vivo stability, bioavailability, therapeutic effectiveness, side effects, plasma fluctuations, and difficulty crossing physiological barriers, like the brain blood barrier (BBB), to deliver the drug directly to the site of action.

Area covered: Nanotechnology-based approaches with the employment of liposomes, micelles, dendrimers, and solid lipid nanoparticles (SLN) as drug delivery systems, are used to overcome the above reported limitations. Here, we focus on the delivery of drugs based on SLN formulation to treat neurodegenerative diseases. Notably, SLN have the ability to protect drugs from chemical and enzymatic degradation, direct the active compound towards the target site with a substantial reduction of toxicity for the adjacent tissues, and pass physiological barriers increasing bioavailability without resorting to high dosage forms.

Expert opinion: We believe that SLN could represent a suitable tool to pass the BBB and permit drugs to reach damaged areas of the CNS in patients affected by neurodegenerative pathologies, such as Alzheimer’s and Parkinson’s diseases.     

Pharmaceutical development and clinical effectiveness of a novel gel technology for transdermal drug delivery

Transdermal gels are designed to deliver sustained drug amounts, resulting in systemically consistent levels. They represent an improvement compared with transdermal delivery by patches because they offer more dosage flexibility, less irritation potential and a better cosmetic appearance. Advanced Transdermal Delivery? (ATD?) gel technology was developed in order to provide enhanced passive skin permeation of various active drugs for the treatment of many conditions, including hypogonadism, female sexual dysfunction, postmenopausal symptoms, overactive bladder and anxiety. The technology consists of a combination of solvent systems and permeation enhancers enabling systemic drug delivery, and is covered by many patents. Pharmaceutical development of formulations based on the technology allowed optimisation of physicochemical parameters (rheological profile, pH) as well as skin permeation properties (type and concentration of permeation enhancers, thermodynamic activity of the drug). This gel technology has demonstrated to be efficient for many drugs, as shown in the preclinical and clinical pharmacokinetic studies presented in this technology evaluation.     

Potential of novel drug delivery strategies for the treatment of hyperlipidemia

Emergence of hyperlipidemia in urban population of India and the world at large is very high and accounts to several fatal diseases. This condition is known to manifest elevated levels of lipids and/or lipoproteins. Serious limitations like inadequate solubility, less absorption, less bioavailability, ineffectiveness in lowering of cholesterol levels, patient incompliance and so on are noticed with majority of anti-hyperlipidemic drugs and dosage forms, which are used conventionally. To overcome these shortcomings, building technology platforms for development of appropriate dosage forms is the need of the hour. These efforts are required to maximize patient acceptability while maintaining safety, efficacy, accessibility and affordability. Hyperlipidemia, its types, etiology, pathophysiology and conventional dosage forms are discussed here. The current approaches and novel developments which illustrate controlled drug release and sustained therapeutic effect along with site specific and target oriented drug delivery with better patient compliance are also reviewed critically. Despite the incentives provided by the efforts of formulation scientists, there is still a need for implementation of pharmaceutical technologies that enable to combat limitations of anti-hyperlipidemic drugs and conventional dosage forms associated with it. The present review emphasize on applications of novel drug delivery systems in pharmacotherapy of anti-hyperlipidemic drugs demonstrating the advantages and disadvantages.     

Advances in brain drug targeting and delivery: limitations and challenges of solid lipid nanoparticles

Introduction: With the advancement in the field of medical colloids and interfacial sciences, the life expectancy has been greatly improved. In addition, changes in the human lifestyle resulted in development of various organic and functional disorders. Central nervous system (CNS) disorders are most prevalent and increasing among population worldwide. The neurological disorders are multi-systemic and difficult to treat as portal entry to brain is restricted on account of its anatomical and physiological barrier.

Areas covered: The present review discusses the limitations to CNS drug delivery, and the various approaches to bypass the blood brain barrier (BBB), focusing on the potential use of solid lipid nanoparticles (SLN) for drug targeting to brain. The methods currently in use for SLN production, physicochemical characterization and critical issues related to the formulation development suitable for targeting brain are also discussed.

Expert opinion: The potential advantages of the use of SLN over polymeric nanoparticles are due to their lower cytotoxicity, higher drug loading capacity and scalability. In addition, their production is cost effective and the systems provide a drug release in a controlled manner up to several weeks. Drug targeting potential of SLN can be enhanced by attaching ligands to their surface.