Inactive ingredients are components of a drug product that do not increase or affect the therapeutic action of the active ingredient, which is usually the active drug. Inactive ingredients are added during the manufacturing process of pharmaceutical products such as tablets, capsules, suppositories, and injections. Inactive ingredients may also be referred to as inert ingredients or excipients, and generally have no pharmacological effect. Examples of inactive ingredients include binding materials (which may be excipients), dyes, preservatives, and flavoring agents. Agents that combine with active ingredients to facilitate drug transport in the body are also considered inactive.
The FDA approves inactive ingredients that are included in pharmaceutical products. However, not all inactive ingredients are always inactive. Alcohol is one example of an ingredient that may be active or inactive based on the specific formulation of the medication. Patients may have allergic reactions or other adverse effects to inactive ingredients. If a patient has a known allergic reaction to an inactive ingredient, they should check for the ingredient in new prescription or over-the-counter medications or check with their pharmacist. Examples of inactive ingredients that are have been reported to cause reactions in some patients include: sulfites, benzoates, aspartame, saccharin, oleic acid, benzyl alcohol, lactose, soya lecithin, propylene glycol, and sorbitan trioleate. Patients who have allergic or adverse reactions to certain inactive ingredients may be able to use products that are color- or preservative-free.