HPLC Separation of Acetaminophen, Phenylephrine, and Diphenhydramine

Primesep C separates acetaminophen (paracetamol), phenylephrine, and diphenhydramine– common over-the-counter cold and flu medication ingredients such as Tylenol products—by either an acetonitrile or phosphoric acid gradient. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN), and phosphoric acid with ultraviolet (UV) detection at 210 nm.