Timed treatment of the arthritic diseases: a review and hypothesis

Chronopharmaceutics: gimmick or clinically relevant approach to drug delivery?

Due to advances in chronobiology, chronopharmacology, and global market constraints, the traditional goal of pharmaceutics (e.g. design drug delivery systems with a constant drug release rate) is becoming obsolete. However, the major bottleneck in the development of drug delivery systems that match the circadian rhythm (chronopharmaceutical drug delivery systems: ChrDDS) may be the availability of appropriate technology. The last decade has witnessed the emergence of ChrDDS against several diseases. The increasing research interest surrounding ChrDDS may lead to the creation of a new sub-discipline in pharmaceutics known as chronopharmaceutics. This review introduces the concept of chronopharmaceutics, addresses theoretical/formal approaches to this sub-discipline, underscores potential disease-targets, revisits existing technologies and examples of ChrDDS. Future development in chronopharmaceutics may be made at the interface of other emerging disciplines such as system biology and nanomedicine. Such novel and more biological approaches to drug delivery may lead to safer and more efficient disease therapy in the future.

Rhythms in the immune system

This report reviews the evidence that cells within the immune system are subject to rhythmic influences that affect numbers of circulating cells and their function both in vitro and in vivo. It is concluded that, although periodicity has clearly been demonstrated for numbers of immunocompetent cells in the circulation, significant functional changes have not been consistently observed. A number of neuroendocrine hormones, which modulate immune responsiveness in vitro and which are released in a rhythmic manner, are considered as mediators of the observed effects on the immune system and this is related to changes in expression and activity of immune-mediated diseases such as rheumatoid arthritis.