A pharmaceutical composition comprising a co-crystal of an API and a co-crystal forming compound wherein the API has at least one functional group selected from ether, thioether, alcohol, thiol, aldehyde, ketone, thioketone, nitrate ester, phosphate ester, thiophosphate ester, ester, thioester, sulfate ester, carboxylic acid, phosphonic acid, phosphinic acid, sulfonic acid, amide, primary amine, secondary amine, ammonia, tertiary amine, sp2 amine, thiocyanate, cyanamide, oxime, nitrile diazo, organohalide, nitro, s-heterocyclic ring, thiophene, n-heterocyclic ring, pyrrole, oheterocyclic ring, furan, epoxide, peroxide, hydroxamic acid, imidazole, pyridine and the co-crystal forming compound has at least one functional group selected from amine, amide, pyridine, imidazole, indole, pyrrolidine, carbonyl, carboxyl, hydroxyl, phenol, sulfone, sulfonyl, mercapto and methyl thio, such that the API and co-crystal forming compound are capable of co-crystallizing from a solution phase under crystallization conditions.Linvention concerne une composition pharmaceutique comprenant un co-cristal de API et un composé formant un co-cristal. LAPI présente au moins un groupe fonctionnel sélectionné parmi: éther, thioéther, alcool, thiol, aldéhyde, cétone, thiocétone, ester de nitrate, ester de phosphate, ester de thiophosphate, ester, thioester, ester de sulfate, acide carboxylique, acide phosphonique, acide phosphinique, acide sulfonique, amide, amine primaire, amine secondaire, ammoniac, amine tertiaire, amine sp2, thiocyanate, cianamide, oxime, diazo nitrile, organohalogénure, nitro, anneau s-hétérocyclique, thiophène, anneau n-hétérocyclique, pyrrole, anneau o-hétérocyclique, furane, époxyde, peroxyde, acide hydroxamique, imidazole, pyridine et le composé formant cristal présentant au moins un groupe fonctionnel sélectionné parmi: amine, amide, pyridine, imidazole, indole, pyrrolidine, carbonyle, carboxyle, hydroxyle, phénol, sulfone, sulfonyl, mercapto et méthyl thio, notamment
