The present invention provides lyophilized formulations of active agents, particularly of TAT-NR2B9c, as chloride salts. TAT-NR2B9c has shown promise for treating stroke, aneurysm, subarachnoid hemorrhage and other neurological or neurotraumatic conditions. The chloride salt of TAT-NR2B9c shows improved stability compared with the acetate salt form of prior formulations. Formulations of the chloride salt of TAT-NR2B9c are stable at ambient temperature thus facilitating maintenance of supplies of such a formulation in ambulances for administration at the scene of illness or accident or in transit to a hospital.
