Nanoparticle drug delivery systems Sample Clauses

Nanoparticle drug delivery systems. 1.3.1. Definition Nanoparticles are defined simply as solid, colloidal particles that vary in size from 10 to 1000 nm (Xxxxxxx et al., 2003). A therapeutic agent may be dissolved, entrapped, adsorbed, attached or encapsulated into the nanoparticle matrix. Depending on their structure, nanoparticles can be further classified as either nanospheres (NS) or nanocapsules (NC) (Figure 1.7). Nanospheres are matrix systems in which the therapeutic agent is physically and uniformly dispersed, whereas nanocapsules are vesicular systems in which the drug is confined to a cavity surrounded by a polymer membrane (Xxxxxxx et al., 2003). Nanoparticles can be made from biocompatible and biodegradable materials such as solid lipids or polymers which may be natural (e.g. gelatin) or synthetic (e.g. poly (lactide)) (Xxxxxxxxx et al., 2001). Liposomes, nanovesicular structures produced from natural phospholipids, are the most widely investigated delivery system for phagocyte-targeted therapies (Xxxxx et al., 2010). However, it is beyond the scope of this review to describe these nanoparticulate systems and highlight their advantages and method of manufacture. High carrier capacity, high stability and the feasibility of incorporating both hydrophobic and hydrophilic drugs are among the important technological advantages of nanoparticles as drug carriers. In addition, it has been claimed that the clearance of drug-loaded nanoparticles from the lung can be minimized to enhance drug retention at topical sites (Xxxxxxx et al., 1990). Such properties make nanoparticles a very attractive delivery vehicle for the treatment of pulmonary TB.