503A vs 503B (pharmacy compounding)
Where a compounded drug parts company with an FDA-approved one, where 503A parts company with 503B, and which accreditation programs tell them apart.
Definition
The two FDA categories of sterile compounder, and the distinction worth learning before you buy. A 503A is state-licensed and compounds against a prescription naming you. A 503B registers voluntarily with FDA, can compound in bulk without prescriptions, and must meet full current Good Manufacturing Practice. Same molecule, different oversight, and sellers rarely volunteer which one fills their orders.
GLP Watchdog writes these definitions from FDA labels and peer-reviewed PubMed literature. Not one of them is an AI-generated summary.
Other terms under Pharmacy and drug forms
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