Lipid-Based Nanoparticles for Enhancing Oral Bioavailability of Drugs



Varshosaz J¹ Show Affiliations
Source: Biocompatible Nanomaterials: Synthesis, Characterization and Applications Published:2011

Abstract

The use of formulations containing natural and/or synthetic polymers as a potential strategy for improving the oral bioavailability of drugs has received increasing interest in recent years. Low bioavailability of drugs may be as a result of their poor-water solubility or sever hepatic first-pass metabolism. For poorly water-soluble compounds, lipids are believed to assist absorption by reducing the inherent limitations of slow and incomplete dissolution and by facilitating the formation of colloidal species within the intestine that are capable of maintaining poorly water-soluble drugs in solution. The co-administration of drugs with lipids can also influence the drug absorption pathway. Whilst most orally administered drugs gain access to the systemic circulation via the portal blood, some highly lipophilic drugs are transported to the systemic circulation via the intestinal lymphatics, thereby avoiding hepatic first-pass metabolism. Solid lipid nanoparticles (SLNs) and nano-structured lipid carriers (NLC) are novel colloidal delivery systems with many therapeutic features that consist of solid matrix and can be described as emulsions in which the liquid-lipid oil is replaced by a solid-lipid or a mixture of solid/liquid lipids. In this review, we have summarized the efforts made by different groups to incorporate the actives in lipid nanoparticles, and the success of the drug delivery system has achieved till date with the focus on oral route of administration. The possibility of enhancing oral bioavailability of both poorly and highly-water-soluble drugs with extensive first pass metabolism will be discussed. Encapsulating of these drugs in SLNs can effectively target them to Peyer's patches, paracellular pathway or the mix of both pathways. Moreover the solid state of the particles of SLNs at room temperature achieve long-term drug carrier with sustained release properties. © 2010 by Nova Science Publishers, Inc. All rights reserved.