Gelatin-coated magnetic iron oxide nanoparticles as carrier system: drug loading and in vitro drug release study.

Magnetic iron oxide nanoparticles (IOPs) were coated with gelatin A and B and drug-loading efficiency was investigated using doxorubicin (DXR) as a model drug to evaluate their potential as a carrier system for magnetic drug targeting. Drug loading to coated IOPs was done using adsorption as well as desolvation/cross-linking techniques to understand their role. Drug loading by adsorption technique was done by incubating mixture of coated IOPs and drug in various conditions of pH, DXR-to-coated IOPs ratio, gelatin types and IOPs amounts. Drug loading by desolvation/cross-linking technique was done by adding acetone and glutaraldehyde (GTA) to the mixture of coated IOPs and DXR. The results indicated involvement of electrostatic interaction during loading of DXR-to-coated IOPs. Compared to adsorption technique, desolvation/cross-linking technique improved the efficiency of drug loading regardless of type of gelatin used for the coating. The DXR-loaded particles showed pH responsive drug release leading to accelerate release of drug at pH 4 compared to pH 7.4.