The active ingredient is the same. The rest is negotiable.
Every branded drug and its generic version must contain the same active pharmaceutical ingredient at the same dosage. That is not a marketing claim, it is a legal requirement under India's Drugs and Cosmetics Act, enforced by the Central Drugs Standard Control Organisation (CDSCO). When your chemist hands you a strip of metformin 500 mg from an Indian generic manufacturer instead of the original branded version, the metformin molecule is chemically identical.
