Excipients and non-medicinal agents as active pharmaceutical ingredients

“Atypical Actives” are a class of excipients that serve as Active Pharmaceutical Ingredients (APIs) in over-the-counter (OTC) medications. Atypical actives are present in a variety of dosage forms administered through oral, topical, parenteral and ophthalmic routes. Most atypical actives are derived from a natural source and hence pose fewer side effects compared to prescription medications. In spite of the advantages associated with the use of atypical actives, they have never shared the spotlight with APIs and are continuously disregarded or ignored. This chapter intends to highlight atypical actives and non-medicinal agents in OTC drug products with an emphasis on their therapeutic properties.