Encapsulation possibilities of an extensively investigated neuroprotective drug (kynurenic
acid, KYNA) are studied via lipid-based nanocarriers to increase the blood–brain barrier
(BBB) specific permeability. The outcomes of various preparation conditions such as
stirring and sonication time, concentration of the lipid carriers and the drug, and
the drug-to-lipid ratio are examined. Considering the experimentally determined encapsulation
efficiency, hydrodynamic diameter, and ζ-potential values, the initial lipid and drug
concentration as well as the stirring and sonication time of the preparation were
optimized. The average hydrodynamic diameter of the prepared asolectin-(LIP) and water-soluble
lipopolymer (WSLP)-based liposomes was found to be ca. 25 and 60 nm under physiological
conditions. The physicochemical characterization of the colloidal carriers proves
that the preparation of the drug-loaded liposomes was a successful process, and secondary
interactions were indicated between the drug molecule and the polymer residues around
the WSLP membrane. Dissolution profiles of the active molecule under physiological
conditions were registered, and the release of the unformulated and encapsulated drug
is very similar. In addition to this outcome, the in vitro polar brain lipid extract
(porcine)-based permeability test proved the achievement of two- or fourfold higher
BBB specific penetration and lipid membrane retention for KYNA in the liposomal carriers
relative to the unformatted drug.
