Abstract:
Three-dimensionally organized lipid cubic self-assemblies and
derived oil-in-water emulsions called “cubosomes” are attractive for various
biotechnological applications due to their ability to be loaded with functional
molecules and their associated sustained release properties. Here, we employed
both of these lipid-based systems for the delivery of a model drug, aspirin, under
comparable conditions. Studies were performed by varying drug-to-lipid ratio
and the type of release medium, water and phosphate buffer saline (PBS).
Release rates were determined using UV−vis spectroscopy, and small-angle Xray
scattering was used to confirm the type of self-assembled nanostructures
formed in these lipid systems. The release from the bulk lipid cubic phase was
sustained as compared to that of dispersed cubosomes, and the release in PBS
was more efficient than in water. The tortuosity of the architecture, length of the
diffusion pathway, type of nanostructure, and physicochemical interaction with
the release media evidently contribute to these observations. This work is
particularly important as it is the first report where both of these nanostructured lipid systems have been studied together under
similar conditions. This work provides important insights into understanding and therefore controlling the release behavior of
lipid-based drug nanocarriers.