A product that contains a chemical with established biological effects is referred to as a pharmaceutical or medical product. The term "active compound" refers to a substance that is normally a drug or pro-drug, which is an inactive medication or compound that becomes an active drug upon ingestion. However, it can also have a cellular component or contain other elements such as preservatives, containment (a material that can shield users or the environment from high toxicity), etc. The medication enters the body through one of three routes: (1) ingestion and absorption in the digestive tract; (2) passive transfer through tissues that are porous, such as the skin, lungs' alveoli, and mucous m...