ABSTRACT - 600479 The disclosure relates to a co-crystal of agomelatine, characterised in that it is composed of: (i) agomelatine, or N-[2-(7-methoxy-1-naphthyl)ethyl]acetamide of formula (I), and (ii) an organic acid which is in a solid state at ambient temperature chosen from parahydroxybenzoic acid, citric acid, oxalic acid, gallic acid, maleic acid, malonic acid, glutaric acid, glycolic acid or ketoglutaric acid. Also disclosed is a process for obtaining said co-crystal comprising the following steps wherein: (i) the two constituents are mixed in an organic solvent in the desired proportions (1 equivalent of agomelatine per 0.25 to 4 molar equivalents of organic acid), preferably the two constituents are co-ground； (ii) the solution obtained is stirred and optionally heated at a temperature not greater than the boiling point of the selected solvent； (iii) the mixture is cooled, with stirring, and the co-crystal precipitates naturally or precipitates after taking up in a second solvent； (iv) the precipitate obtained is filtered and dried. These co-crystals are suitable for treating stress, sleep disorders, anxiety disorders and especially generalised anxiety disorder, obsessive-compulsive disorders, mood disorders and especially bipolar disorders, major depression, seasonal affective disorder, cardiovascular pathologies, pathologies of the digestive system, insomnia and fatigue due to jet-lag, schizophrenia, panic attacks, melancholia, appetite disorders, obesity, insomnia, pain, psychotic disorders, epilepsy, diabetes, Parkinson's disease, senile dementia, various disorders associated with normal or pathological ageing, migraine, memory loss, Alzheimer's disease, and also in cerebral circulation disorders, and also in sexual dysfunctions, and as ovulation inhibitors and immunomodulators and in the treatment of cancers.
