The present invention relates to improved pharmaceutical compositions that contain high concentrations of one or more protein biomolecule(s). In particular, the invention relates to such pharmaceutical compositions that include one or more amino acid molecules, particularly arginine, alanine, glycine, lysine or proline, or derivatives and salts thereof, or mixtures thereof, as stabilizing compounds. The inclusion of such stabilizing compounds decreases reconstitution time whilst improving and/or maintaining the long-term stability of the protein biomolecule, so as to facilitate the treatment, management, amelioration and/or prevention of a disease or condition by the pharmaceutical composition. The invention particularly pertains to such pharmaceutical compositions that lack, or substantially lack, a sugar stabilizing agent.