**4. Future prospects and challenges with vesicular and solid lipid nanoparticulate drug delivery system**

Nanostructured lipid carriers contain an unsaturated solid lipid core that enables the encapsulation of highly lipophilic drugs, protecting them from degradation, and enhancing their stability. Literature indicates that during the past decades, the number of studies elaborating NLCs-based formulations has been drastically increased. Lipid nanostructure carriers such as SLNs, VDDs, and or NLCs have been extensively used and further investigated as carrier systems for drug delivery. Moreover, these nanostructure carrier has demonstrated excellent improvement in the therapeutic efficacy with an increase in targeting specific tissue or organ for low permeable and water-insoluble drugs. The rise in NLCs technology is essentially due to defeated barriers within the technological process of lipid fortified nanoparticles formulation and increased knowledge of the underlying mechanisms of transport of NLCs via varied routes of administration. Although NLCs have shown several advantages, compared with conventional dosage form and promising application in the delivery of various categories of synthetic and bioactive, that presents challenges in their application. The challenges associated with NLCs are as follow: complex manufacturing process, stability during storage, clinical translational barriers, cell-specific delivery, misconceptions, challenges specific to the receptor, ligand, and carriers, etc. [77].

*Lipid Nanoparticulate Drug Delivery Systems: Approaches toward Improvement in Therapeutic… DOI: http://dx.doi.org/10.5772/intechopen.104510*
