The invention relates to controlled release compositions comprising metformin or its pharmaceutically acceptable salts in combination with pioglitazone or its pharmaceutically acceptable salts and one or more pharmaceutically acceptable excipient and to their process of preparation. More particularly the invention relates to controlled release tablet comprising a combination of metformin or its pharmaceutically acceptable salts and pioglitazone or its pharmaceutically acceptable salts, wherein said tablet is devoid of any passage-way.
