Liposomal carriers parenteral administration

Parenteral administration to man, in Liposomes as Drug Carriers Recent Trends and Progress (G. Gregoriadis, ed.), John Wiley and Sons, Chichester, pp. 795-817. 

Nanoparticles have been studied extensively as carriers for drugs employed in a wide variety of routes of administration, including parenteral [14], ocular [15], and peroral [16] pathways. The term nanoparticle is a collective name for any colloidal carrier of submicrometer dimension and includes nanospheres, nanocapsules, and liposomes. They can all be defined as solid carriers, approximately spherical and ranging in size from 10 to 1000 nm. They are generally polymeric in nature (synthetic or natural) and can be biodegradable... 

Parenteral is defined as situated or occurring outside the intestine, and especially introduced otherwise than by way of the intestines —pertaining to essentially any administration route other than enteral. This field is obviously too broad for an adequate focus in one book, let alone one chapter. Many have nonetheless used the term synonymously with injectable drug delivery. We restrict ourselves to this latter usage. This would thus include intravenous, intramuscular, subcutaneous, intrathecal, and subdural injection. In this chapter we discuss the theoretical and practical aspects of solubilizing small molecules for injectable formulation development and will examine the role of surfactants and other excipients in more recent parenteral delivery systems such as liposomes, solid-drug nanoparticles and particulate carriers. 

Liposomes as a dosage form allow for a broad variety of administration routes. In addition to the most traditional and frequent parenteral (intravenous) way of administration, some alternative approaches are also developed or under development, although each of these approaches has its own problems and limitations. Thus, oral administration requires high liposome stability and drug delivery from the gut to the blood with subsequent drug release. Early attempts with polymerized liposomes as potential oral vaccine carriers were only partially successful. Currently, many alternative schemes are under development. 

---