Impact of liposomes as delivery systems in veterinary medicine.

Abstract

The development of drug resistance and the inability of the drug to reach the location of the etiologic agents are major challenges for anti-infective and cancer therapies. As the development of new drugs with improved pharmacodynamic and pharmacokinetic properties is a slow and difficult process, drug delivery systems appear as promising alternatives. Liposomes are lipid vesicles formed when phospholipids are exposed to an aqueous environment. They arrange themselves in bilayers and close up, forming a vesicle. During this process they capture the aqueous phase of the dispersion, and any substance dissolved in it, within the vesicle. Liposomes have remarkable features that make them an almost ideal delivery system. They are biodegradable, with few side effects, can deliver drugs with different physico-chemical properties together and can be formulated for different routes of administration. The potential to modify the pharmacokinetic behaviour of encapsulated drugs to deliver them selectively to the site of action is the most important feature of liposomes as drug delivery systems. Liposomes are already used in human medicine for he treatment of bacterial, viral and parasitic diseases, and cancer. They have also been proven useful as immunoadjuvants and vaccines. Liposomes are used in certain avian vaccines. The possible uses of liposomes and their impact in veterinary medicine in the treatment of infectious diseases and cancer as well as in the prevention of diseases are discussed in the present article.