A water-soluble aspirin-theanine cocrystal composition which includes a quantity of acetylsalicylic acid and a quantity of a theanine enantiomer or carbohydrate or amino acid derivative thereof associated with the quantity of acetylsalicylic acid. The composition may be created by a method including the steps of : (i) providing a quantity of acetylsalicylic acid (ii) adding a quantity of a theanine enantiomer to the quantity of acetylsalicylic acid to form a mixture comprising the quantity of acetylsalicylic acid and the enantiomer of theanine (iii) wetting the mixture and (iv) grinding the mixture for a length of time sufficient to produce a dried crystalline mass. The water-soluble cocrystal composition is suitable for intravenous administration, preferably to humans.