Transfer of A Lipophilic Drug Model from Lipid Nanoparticle Carriers to A Lipophilic Acceptor Compartment

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) are attracting increasing attention as colloidal drug carriers for intravenous application. In order to obtain information on their potential in-vivo performance, a simple and effective in-vitro assay that mimics the environment encountered by the drug upon administration is required. In this study, unilamellar vesicles as a lipophilic acceptor compartment were used for such investigations. Trimyristin (D114) and Miglyol oil were chosen as the solid and liquid lipid respectively and porphyrin was used as a model lipophilic drug. Properties of these lipid nanoparticles such as particle size and its distribution, zeta potential and entrapment efficiency were investigated. The determination of the transferred drug to the acceptor particles was performed after the separation between the donor and acceptor particles on an ion exchange column. As a result, the entrapment efficiency was improved by adding liquid lipid to the solid lipid. On the other hand, both population donor and acceptor were effectively separated using ion exchange columns. Higher amount of porphyrin was transferred from the donor NLC to the acceptor in comparison with SLN. On the contrary, the transfer rate constant from the donor SLN was slightly higher than from NLC. These results indicate that the Ion exchange column is a suitable technique to study the transfer of lipophilic drug models but one of the two populations donor or acceptor should be charged. In addition, NLC could be used as a colloidal lipid carrier with improved drug loading capacity.