Abstract: There is provided a prodrug of a pharmaceutically active agent, such prodrug comprising a beta-keto carboxylic acid, a beta-keto carboxylic acid salt or a beta-keto carboxylic acid ester functional group, a pharmaceutical composition comprising the prodrug, and to the use of the prodrug or composition for treatment of a mammalian subject suffering from a condition which can be cured or alleviated by administration of the pharmaceutically active agent. There is further provided a method of inhibiting decarboxylation of a compound comprising a beta-keto carboxylic acid or a salt thereof with a monovalent cation, characterized in that a dry salt of the beta-keto carboxylic acid with a divalent or polyvalent cation is prepared.