Abstract: The present invention provides lyophilized formulations of active agents, particularly of TAT-NR2B9c including histidine, trehalose and lysine. TAT-NR2B9c has shown promise for treating stroke, aneurysm, subarachnoid hemorrhage and other neurological or neurotraumatic conditions. Such formulations 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.