Fast disintegrating solid dosage form formulation comprising functionalized calcium carbonate and method of their manufacture

An orally fast disintegrating dosage forms comprising functionalized natural or synthetic calcium carbonate, at least one active ingredient and at least one disintegrant, wherein said functionalized natural or synthetic calcium carbonate is a reaction product of natural or synthetic calcium carbonate with carbon dioxide and one or more acids, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source, and wherein the tablet dissolves in less than 20 seconds when introduced into an aqueous environment.