Evaluating delivery of a monoclonal antibody using a linear Lorentz-force actuated needle-free injector

Abstract

The medical application of injection of monoclonal antibodies using a controllable auto-loading needle-free jet injector has been evaluated for two potentially limiting factors: viscosity of the formulation and shearing of the antibody during ejection. We used the Hepatitis B monoclonal antibody C86322M for its easy access and widespread usage. We used repeatability studies of glycerol at up to 200 m/s and 200 [mu]L delivery volume to demonstrate precision at viscosities up to 21.6x10-³ Pa-s. We determined that viscosity alone would not limit the jet injector's performance. Additionally, we evaluated the integrity of the antibody post-ejection using the enzyme-linked immunosorbent assay (ELISA) and gel electrophoresis methods. Using the ELISA method, we compared the ability of the antibody to bind to its specific antigen, HBsAg, both before and after ejection at multiple speeds. Changes in molecular size and charge of the monoclonal antibodies were evaluated by gel electrophoresis, more specifically with SDS polyacrylamide gels in reducing and non-reducing situations, native gel electrophoresis, and IEF gel electrophoresis. Most of these techniques revealed little to no change between pre-ejectate and ejectate migration, indicative of an unchanging molecular size and overall charge. However, with IEF gel electrophoresis, we observed two extra residues around a pI of 6.8. A change in charge due to alterations of protein side-chains may affect the stability of the molecule, and so this result is worth further pursuing on a quantitative basis. Despite this possibility, overall we have demonstrated that at 1 g/L, no significant aggregation or degradation results from jet ejection.