Active Pharmaceutical Ingredient [API]

Bioavailability is the fraction (percentage) of an administered dose of unchanged drug that reaches the blood stream (systemic circulation). Bioavailability varies between different pharmaceutical ingredients and mode of administration.

Generic medicines are copies of original, branded medicines. They can be manufactured and sold after the protection on an original product expires. They have the same form and active pharmaceutical ingredient as the original medicine, and they are regulated according to the same standards.

Biosimilars are medicines that are designed to be similar to previously approved biologic medicines.

Early clinical trials (Phase I and II) must establish above all that an investigational medicinal product is safe for humans, as well as to show that the medicine is effective against the intended disease or condition.