Pharmaceutical science & technology today最新文献

The use of liposomal drug delivery systems to improve the therapeutic index of pharmaceutical agents is exemplified by camptothecin-based drugs. This highly active class of anticancer agents possesses a unique mechanism of action with some inherent shortcomings, which might have been solved by liposomal formulation. Recent studies have revealed the protective action, increased tumor delivery and prolonged plasma exposure of these liposomal formulated drugs. These advances in pharmaceutical development could increase the levels of activity of these agents, as well as increase their clinical utility as new emerging anticancer therapies.

The majority of oral drug delivery systems (DDS) are matrix-based. Swellable matrices are monolithic systems prepared by compression of a powdered mixture of a hydrophilic polymer and a drug. Their success is linked to the established tabletting technology of manufacturing. Swellable matrix DDS must be differentiated from true swelling-controlled delivery systems. This review focuses on hydrophilic swellable matrix tablets as controlled DDS. Gel-layer behaviour, front movement and release are described to show the dependence of the release kinetics on the swelling behaviour of the system. In vivo behaviour of matrix systems is also considered.

Interferons (IFNs), with annual global sales valued at more than US$4 billion, have therapeutic value in the treatment of viral, neoplastic and autoimmune diseases. Parenteral administration by high-dose injection can, however, cause serious side effects. Significant improvement in the therapeutic index of IFNs could be achieved with oral administration. Using this route, dose-related side effects are not seen, and efficacy is maintained in both animal studies and human clinical trials. Oral IFN administration appears to mimic a natural innate immune response. As such, it may represent an alternative delivery strategy to make better use of these critical cytokines.

Colloidal drug carriers such as liposomes and nanoparticles can be used to improve the therapeutic index of both established and new drugs by modifying their distribution, and thus increasing their efficacy and/or reducing their toxicity. This is because the drug distribution then follows that of the carrier, rather than depending on the physicochemical properties of the drug itself. If these delivery systems are carefully designed with respect to the target and the route of administration, they may provide one solution to some of the delivery problems posed by new classes of active molecules, such as peptides and proteins, genes and oligonucleotides. They may also offer alternative modes for more conventional drugs, such as highly hydrophobic small molecules. This review discusses the use of colloidal, particulate carrier systems (25 nm to 1 μm in diameter) in such applications.

Monitor provides an insight into the latest developments in pharmaceutical science and technology through brief synopses of recent presentations, publications and patents, and expert commentaries on the latest technologies. There are two sections: Progress summarizes the latest developments in pharmaceutical process technology, formulation, analytical technology, sterilization, controlled drug delivery systems and regulatory issues; Profiles offers expert commentary on emerging technologies, novel processes and strategic, organizational and logistic issues underlying pharmaceutical R&D.