The present invention relates to a powder for reconstitution before use for preparations for injection containing melatonin, at least one soluble excipient and at least one surfactant for the treatment of neonatal cerebral infarction. The present invention also relates to a preparation for injection in the form of a solution obtained by dissolving a powder to be reconstituted comprising melatonin, at least one soluble excipient and at least one surfactant, in a mixture of water and polyalkylene glycol, in which the melatonin is present in quantities of from 3 to 30 mg/ml and the polyalkylene glycol is present in quantities from 5 to 40% of the total volume of the liquid used.
