drugs
Bioequivalence and Interchangeability of Generic Drugs
Introduction
Medications are drugs used therapeutically (that is, to treat medical conditions). When one company develops a generic version of another company's brand-name drug, the new company’s experts in drug formulation must figure out how to make the drug. It is not enough for them to simply reproduce the brand-name drug’s chemical structure or to buy the active ingredient from a chemical manufacturer. (See also Overview of Generic Drugs and Drug Naming .) Although 250 milligrams (mg) of a brand-name chemical is identical to 250 mg of the same generic chemical, a 250-mg generic pill containing that chemical may or may not have the same effect in the body as a 250-mg brand-name pill. That is because everything that is used in a particular product formulation affects how it is absorbed into the bloodstream. Inactive ingredients such as coatings, stabilizers, fillers, binders, flavorings, diluents, and others are necessary to turn a chemical into a usable drug product. These ingredients may be used to Provide bulk so that a tablet is large enough to handle Keep a tablet from crumbling between the time it is manufactured and the time it is used Help a tablet dissolve in the stomach or intestine Provide a pleasant taste and color Inactive ingredients are usually harmless substances that do not affect the body. However, because inactive ingredients can cause unusual and sometimes severe allergic reactions in a few people, one version, or brand, of a drug may be preferable to another. For example, chemicals called bisulfites (such as sodium metabisulfite), which are used as preservatives in many products, cause asthmatic allergic reactions (wheezing, shortness of breath, chest tightness) in many people. Consequently, drug products containing bisulfites are prominently labeled as such. 