Drug substance

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An ingredient intended to exert pharmacologic action or other direct effect in the diagnosis, cure, mitigation, or prevention of disease or to affect any function of the body. Along with other ingredients (excipients,) it is used to formulate a medicinal product.

Synonyms:
Active Pharmaceutical ingredient, API
Related Articles:
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  • Glossary: Bioéquivalence
  • Bioavailability and bioequivalence
    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
    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
    Biosimilars are medicines that are designed to be similar to previously approved biologic medicines.
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