Polymer-Lipid Hybrid Nanoparticles (PLN) for the Delivery of Ionic Drugs

The nature of solid lipid nanoparticles (SLN) determines its applications that mainly focus on the delivery of hydrophobic drugs. In addition, the inherent disadvantages of SLN such as low drug loading capacity and significant initial burst release kinetics constituent a real challenge for formulation scientists [1]. In order to deliver hydrophilic drugs, a characteristic chemical structure of anionic polymers (polyanions) was used to develop a PLN system [2]. A lowered burst release and subsequent sustained release kinetics have been observed. However, the drug loading and release mechanisms are still poorly understood. We chose verapamil HCl (VRP), a calcium channel blocking agent and a chemosensitizer for overcoming multidrug resistance, as drug candidate of PLN. Low-molecular-weight dextran sulfate sodium salt, a polyanionic derivative of dextran, was used as counter ion. This study intends to rationally design the PLN formulation through systemic screening of lead lipid candidates and characterization of PLN morphology and drug loading