**1. Introduction**

Nanomedicine is still considered an emerging and effective formulations technique due to the fusion of nanotechnology and medicine, which is one of the most promising ways to develop effective targeted therapies. Several active pharmaceuticals fail to demonstrate the therapeutic efficacy when delivered in conventional dosage forms, which is directly or indirectly linked to their biopharmaceutical classification and hydrophobic nature. Moreover, such poor water-soluble active moiety represents several challenges: low or reduced oral bioavailability, topical permeability, therapeutic efficacy, etc. Nanoparticulate drug delivery systems comprise a wide variety of dosage forms including nanospheres, micelles, solid lipid nanoparticles, nanoliposomes, dendrimers, magnetic nanoparticles, and nanocapsules (**Figure 1**). Lipid nanostructure carriers such as solid lipid nanoparticles (SLNs), vesicular drug delivery system (VDDs), and or nanostructure lipid carriers (NLCs) significantly gained attention among the scientific community due to several advantages including low cost of scale-up with prolonged stability [1]. There are several carriers employed in the delivery of available drugs as an alternative to conventional drug delivery systems such as drug-lipid conjugate, lipid nanocapsules, layersomes, and lipid-polymer nanohybrids. Solid lipid nanoparticles were developed to overcome the limitations of other colloidal carriers, such as emulsions, suspensions, and polymeric nanoparticles due to the effective release mechanism and targeted delivery with physical stability [2]. Nano lipid carriers are modified versions of SLNs that improve the stability and drug loading efficacy. In addition, the potential applications of LNs in drug delivery fabrication, research, topical cosmetics, and clinical medicine indicates its efficacy. These carrier systems are mainly composed of physiologically compatible and
