abstract

A crucial lipid-based nanocarrier technology for improving the administration of medicinal substances with poor aqueous solubility, limited bioavailability, chemical instability, or unfavourable pharmacokinetic characteristics is solid lipid nanoparticles (SLNs). Surfactants stabilise SLNs, which are typically composed of physiologically suitable solid lipids. They offer numerous benefits, including higher bioavailability, better cellular uptake, regulated drug release, protection of integrated medicines against degradation, and the potential for site-specific drug delivery. With an emphasis on formulation components, preparation methods, critical quality attributes, optimisation strategies, drug-release behaviour, characterisation, biological performance, and pharmaceutical applications, the current review highlights the development and optimisation of SLNs for improved drug delivery. Additionally, an academic model formulation-development dataset is provided to demonstrate how the lipid concentration, surfactant concentration, and homogenisation conditions might influence the particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, and drug-release properties. An optimised SLN formulation with a particle size of roughly 158 nm, PDI of 0.214, zeta potential of -28.6 mV, and entrapment efficiency of 89.7% was found by theoretical model optimisation. In contrast to the free-drug suspension, the in vitro release experiments showed a prolonged drug release. In conclusion, SLNs may be a promising platform for enhancing the therapeutic efficacy of unstable and poorly soluble medications. The crucial problems of physical stability, drug ejection during storage, scaling up, manufacturing repeatability, and regulatory standardisation, however, continue to be significant obstacles that require more research.