The development of nanosized drug-carrier systems has been investigated over the past few decades using various techniques. The two main categories of these systems are polymeric nanoparticles and lipid nanoparticles (LNPs). The toxicological risk associated with lipid nanoparticles is significantly lower than the danger associated with polymeric nanoparticles due to the materials' natural and biological origins. Lipid-based drug delivery systems like Nanostructured lipid carriers (NLCs) and Solid Lipid Nanoparticles (SLNs) are well-established nanotechnology systems for preparing all major pharmaceuticals. These delivery systems can be scaled up with easy manufacturing procedures and are biocompatible. NLCs are the second generation of lipid-based nanocarriers (SLNs), formed by combining solid and liquid biocompatible lipids to form an unstructured matrix that provides high entrapment efficiency of active constituents. LNPs can promote the distribution of active pharmaceutical ingredients to the target site. Increasing the active drug concentration to target organ LNPs enhances the therapeutic effectiveness and reduces the side effects. This paper reviews the structure of SLNs and different NLCs, various steps involved in manufacturing lipid nanoparticles, excipients used in the formulation, and applications for targeted drug delivery.