Preparation and in vitro evaluation of carrier erythrocytes for RES-targeted delivery of interferon-alpha 2b

Carrier erythrocytes is one of the most promising systemic drug delivery systems investigated in recent decades. In this study, human erythrocytes have been loaded with interferon-α 2b (IFN) with the aim to benefit the reticuloendothelial system (RES) targeting potential of the carrier cells. Hypotonic preswelling method was used for drug loading in erythrocytes and the entire loading procedure was evaluated and validated. The loaded amount, entrapment efficiency and cell recovery of the loading procedure were 2906.33 ± 588.35 IU/0.1 ml, 14.53 ± 2.94%, and 83.61 ± 0.49%, respectively, all being practically feasible. The carrier erythrocytes were characterized in vitro in terms of their drug release kinetics, hematological indices, particle size distribution, SEM analysis, and osmotic and turbulence fragility. IFN release from carrier cells was a relatively rapid process in comparison to the cell lysis kinetics, which is unusual considering the whole body of data published on this delivery system and other protein drugs, so far. All the tested in vitro characteristics showed significant, sometimes notable changes upon drug loading procedure, both with and without the drug.