A Comprehensive Review on Solid Lipid Nanoparticles as Delivery of Poorly Permeable Drugs

Abstract

Solid lipid nanoparticles (SLNs) are solid core lipid nanocarriers, which can hold both hydrophilic and hydrophobic drugs. They can be made up of biocompatible ingredients and therefore are one of the preferred choices for drug delivery. Surface modifications of SLNs may further provide unique features to them like mucoadhesiveness or targeting capability. Due to their unique size-dependent properties, lipid nanoparticles offer the possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could be used for secondary and tertiary levels of drug targeting. Hence, solid lipid nanoparticles hold great promise for reaching the goal of controlled and site specific drug delivery and hence have attracted wide attention of researchers.Solid lipid, one of the physical forms of lipid, is used to formulate nanoparticles, popularly known as Solid lipid nanoparticles (SLNs), as an alternative carrier system to emulsions, liposomes and polymeric  micro- and nano-particles. SLNs combine advantages of the traditional systems but avoid some of their major disadvantages. This paper reviews numerous production techniques for SLNs along with their advantages and disadvantages. Special attention is paid to the characterization of the SLNs by using various analytical tools.