API: Active Pharmaceutical Ingredient

Think of a tablet the way you would think of a cooked dish, most of what is on the plate is filler, rice, sauce, garnish, but there is one specific ingredient actually responsible for the flavour everyone is there for. The Active Pharmaceutical Ingredient is that one ingredient in a medicine, the actual chemical compound responsible for the drug's therapeutic effect.

A finished tablet or capsule is mostly made up of inactive substances, called excipients, binders, fillers and coatings that give the medicine its physical form, aid absorption, or improve shelf life, with the API itself often making up a comparatively small fraction of the total weight. India has historically been one of the world's largest producers of APIs, though the country has also faced periodic concern over its heavy dependence on China for certain Key Starting Materials that go into producing those very APIs.

When you read about a government push for API self reliance, it is specifically about reducing dependence on imported raw chemical inputs used to manufacture the active ingredient itself, not about the far larger and more visible finished formulation business that actually turns that API into the tablet you take.