Solid lipid nanoparticles are one of the developed technologies for addressing the bioavailability and targeting issues of drug delivery. In this review article, we attempted to incorporate all the essential details of SLNs like various methods of preparation, different models of SLNs, updated characterization methods, in-vivo behavior (Uptake), their applications, route of administration as well as advancements taken place in the field of delivery of biological drugs like gene vector, new adjuvant for vaccines, protein, and peptide with SLNs. Surface modified SLNs hold excellent potential for targeted and controlled drug delivery which is discussed and summarized. Based on the available data, the future success of SLNs is widened because they could be easily fabricated with various functionalities which would display enormous potential for targeting and diagnosing various diseases. This review would help the budding researchers to find out the unexplored areas of SLNs with the present discussion that reframes the potential of SLNs by gathering the various research findings of SLNs in tabular form along with the approved patent technologies of SLNs.

Background: Despite significant biological effects, the clinical use of chrysin has been restricted because of its poor oral bioavailability. Objective: The purpose of the present research was to investigate the targeting potential of Mannose decorated chrysin (5,7- dihydroxyflavone) loaded solid lipid nanocarrier (MC-SLNs) for gastric cancer. Methods: The Chrysin loaded SLNs (C-SLNs) were developed optimized, characterized and further mannosylated. The C-SLNs were developed with high shear homogenizer, optimized with 32 full factorial designs and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) and evaluated for particle size/polydispersity index, zeta-potential, entrapment efficiency, % release and haemolytic toxicity. The ex-vivo cytotoxicity study was performed on gastric cancer (ACG) and normal cell lines. Results: DSC and XRD data predict the chrysin encapsulation in lipid core and FTIR results confirm the mannosylation of C-SLNs. The optimized C-SLNs exhibited a narrow size distribution with a particle size of 285.65 nm. The % Entrapment Efficiency (%EE) and % controlled release were found to be 74.43% and 64.83%. Once C-SLNs were coated with mannose, profound change was observed in dependent variable - increase in the particle size of MC-SLNs (307.1 nm) was observed with 62.87% release and 70.8% entrapment efficiency. Further, the in vitro studies depicted MC- SLNs to be least hemolytic than pure chrysin and C-SLNs. MC-SLNs were most cytotoxic and were preferably taken up ACG tumor cells as evaluated against C-SLNs. Conclusion: These data suggested that the MC-SLNs demonstrated better biocompatibility and targeting efficiency to treat the gastric cancer.