Engineering of phosphatidylcholine-based solid lipid nanocarriers for flavonoids delivery

The present study has been focused on determination and evaluation of three different preparation techniques, i.e., solvent-diffusion, hot homogenization-ultrasonification and microemulsification, applied in fabrication of biocompatible phosphatidylcholine solid lipid nanoparticles ((PC)-SLNs), containing Polawax National Formulary (NF) in the internal lipid phase. The fabricated lipid nanoparticles were loaded with the newly synthesized flavonoid cocrystals, i.e., baicalein–nicotinamide (1:1) (BaiNam), myricetin–piracetam (1:1) (MyrPac) and myricetin–caffeine (1:1) (MyrCaf) cocrystals in relation to the starting flavonoids, differing in solubility and physical state. The assessment of all studied drugs entrapment and availability in aqueous SLN dispersions has been carried out; the size along with size distribution of lipid nanoparticles loaded with the studied flavonoids cocrystals and flavonoids was determined by the DLS technique, while the structural changes—by FT-IR spectroscopy and X-ray powder diffraction (XRPD) of the lipid nanomatrices. XRPD and FT-IR analyses confirmed that parent flavonoids as well as their cocrystals are present in the nanoparticles fabricated with solvent-diffusion method as physical mixtures with the lipid and their crystalline structures at least partially conserved. Summarizing, we designed and fabricated the biocompatible SLN-type nanocarriers of enhanced physical stability and availability for the flavonoids delivery—a vast group of naturally occurring polyphenolic compounds, considered as active pharmaceutical ingredients.