Retrospective statistical analysis of lyophilized protein formulations of progenipoietin using PLS: determination of the critical parameters for long-term storage stability.

Although certain criteria have become recognized as being essential for a stable lyophilized formulation, the relative importance of different stability criteria has not been demonstrated quantitatively. This study uses multivariate statistical methods to determine the relative importance of certain formulation variables that affect long-term storage stability of a therapeutic protein. Using the projection to latent structures (PLS) method, a retrospective analysis was conducted of 18 formulations of progenipoietin (ProGP), a potential protein therapeutic agent.