Compounding

In the field of pharmacy, compounding (performed in a compounding pharmacy) is preparation of custom medications to fit unique prescriptions that cannot be met with mass-produced formulations. This may be done, for example, to provide medication in a form easier for a given person to ingest (e.g., liquid vs. tablet), to avoid a non-active ingredient, or to provide a particular dose tailored to a given person, referred to as "traditional" compounding.

Compounding preparations of a given formulation in advance batches, as opposed to preparation for a specific person on demand, is known as "non-traditional" or "officinal" compounding, and is akin to small-scale manufacturing. Jurisdictions have varying regulations that apply to both traditional and non-traditional compounding, as well as mass-producing drug manufacturers.

Hospital pharmacies typically engage in compounding medications for intravenous administration, whereas outpatient or community pharmacies typically engage in compounding medications for oral or topical administration. Because of the rising cost of compounding and drug shortages, some hospitals outsource their compounding needs, particularly of sterile-injectable medications, to large-scale compounding pharmacies.