Chapter 1 - Lipid nanocarriers

Abstract

Lipid nanocarriers have emerged as a very promising, emerging and rapidly developing tool for the delivery of various drugs lacking solubility, bioavailability and stability in the recent couple of decades. Recent studies show that about 40% of newer drugs have such problems. Initially, a lipid carrier was denoted by the liposome and similar vesicular systems, but currently they are categorized as colloidal nano lipid-based carriers (CNLBC). To avoid the limitation of these CNLBCs in pH- and enzyme-dependent degradation, especially when taken orally or in physical0 and chemical-related stability issues, newer lipid nanocarriers such as solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLCs), lipid drug conjugates (LDCs), and pharmacosomes have shown their importance at greater extent due to low toxicity, improved bioavailability, high biocompatibility, high drug-loading efficiency, protection from degradation in GIT, etc. Lipid nanocarriers can load both hydrophilic and lipophilic drug. Solubility is a rate-limiting step in the case of lipophilic drugs (BCS Class II and IV), which can be greatly modified by formulation of lipid nanocarriers. Similarly, lipidic nanocarriers can increase the permeability of most of the hydrophilic drugs (BCS I and III class) which is the rate limiting step this case. These carriers also shows good controlled and target specific drug delivery system which always attracts the attention of researchers.