Active pharmaceutical ingredients
The pharmaceutical drugs which are biologically active are called active ingredients (AI). In medicine, terms such as bulk active and active pharmaceutical ingredient (API) are also interchangeably used. For natural products, the term active substance is used. There are certain medication products that could comprise of multiple active ingredients. “Pharmacon” or “Pharmakon”, is a traditional word for Active Pharmaceutical Ingredient originally denoting a magical drug or substance.
Often, “active constituent” is used while giving references to the active substance of interest in a plant (For example, arecoline in areca nuts, salicylic acid present in the bark of a willow tree) as the term “active ingredient” may in many sense imply a perception of human agency (something that is manually combined with other substances), whereas the natural products in plants occur naturally and will not be added by human agency. Therefore, the plant does not have ingredients but has active substances.