Drug delivery via anion exchange of salicylate decorating poly(meth)acrylates based on a pharmaceutical ionic liquid

Amphiphilic polymer carriers were designed for the delivery of ionically bonded drugs. The ionic liquid, trimethylammonium methacrylate monomer, containing biologically active salicylate anions was selected for the preparation of copolymers via atom transfer radical polymerization (ATRP) with methyl methacrylate (MMA) or methyl acrylate (MA). The resulting polymers varied in the content and arrangement of ionic units in the chain. The self-assembly of polymers in aqueous solution yielded particles at critical micelle concentration (CMC) values below 0.1 mg ml(-1) and with hydrodynamic diameters in the range of 170-290 nm, which were also visualized by TEM. Drug release studies indicated the exchange of 42-52% of salicylate anions with phosphate anions using dialysis in PBS, which corresponded to 0.15-0.25 mg of salicylate released from 1 mg of polymeric carrier.