Liquid high concentration IgG1 antibody formulations by precipitation.

A manufacturing approach for liquid high concentration antibody formulations based on precipitation and subsequent re-dissolution was investigated. IgG1 antibody solutions were concentrated from 20 to 100 mg/mL by intermediate precipitation, with a recovery exceeding 95%, retention of the native secondary structure and binding activity as well as adequate stability. Quantitative, reproducible precipitation was performed using 1.45 M ammonium sulphate (pH 5.5 and 8.0), 0.67 M sodium citrate (pH 8.0) and 9% (w/v) PEG 4000 (pH 5.5 and 8.0). Scalability was confirmed from 1 to 100 mL. The concentrations achievable in the re-dissolution step were less affected by the re-dissolution medium, but limited by the residual precipitant. Both, improved removal of remaining precipitant liquid and larger precipitation scales were successful in increasing the final protein concentration. SEC and turbidity analysis directly after re-dissolution indicated that similar protein qualities were obtained, independent from the precipitant used. However, increased aggregate formation was observed after short term storage of the precipitated protein particles at either 2-8 degrees C or ambient temperature. An accelerated mechanical and thermal stability program verified comparable stability of the re-dissolved liquid 100 mg/mL formulations produced by intermediate precipitation to a control formulation obtained by standard ultrafiltration.