Extemporaneous compounding of preparations is a worldwide practice dating back centuries. Today, compounding is commonly defined as the preparation of a medicine in accordance with a licensed practitioner’s prescription or medication order. This definition evolves from a triad—the prescribing practitioner, the compounding professional, and the patient/consumer. Historically, what was once viewed as an art is now deeply rooted in the scientific study of how to prepare and assess compounded preparations, together with provision of stability data to allow assignment of a beyond-use date (BUD).