[ HOW-TO GUIDE ]
How to Choose Between 503A and 503B Compounding
Decide which federal compounding route a business model needs, and what each route then requires.
What a how-to is not
A how-to is SPEQ’s practitioner method, not a procedure. It does not replace your own SOP, it is not a validated approach, and the judgement calls in it belong to your quality unit.
Sections 503A and 503B of the FD&C Act are not quality tiers; they are different legal routes with different exemptions and obligations. 503A covers patient-specific compounding by licensed pharmacists and physicians under state oversight. 503B covers outsourcing facilities that register with FDA, may compound without patient-specific prescriptions, and must comply with cGMP. This sequence matches the route to the business and sets up its obligations.
- 1
Describe the business model precisely
Who orders the product, for whom, and how is it supplied? Patient-specific prescriptions dispensed to the patient point to 503A. Supply to hospitals, clinics or physicians for office use without patient-specific prescriptions, for sterile drugs, points to 503B.
- 2
Check the products against each route’s limits
For every product, check the bulk drug substances against the applicable list, the essentially-a-copy restrictions, and FDA’s list of drugs withdrawn for safety or effectiveness reasons. Under 503A, check interstate distribution against the 5 percent limit unless the state has signed FDA’s memorandum of understanding.
- 3
If 503B, register and report
Register with FDA between 1 October and 31 December each year and pay the establishment fee. Report the drugs compounded in the previous six months on registering and every June and December, and set up adverse event reporting.
- 4
Build the quality system the route requires
A 503B facility complies with cGMP under 21 CFR 210/211: validated aseptic processes and sterilisation, environmental and personnel monitoring, stability-based expiry dating and release testing. A 503A pharmacy works to USP <795> and <797> as its state board of pharmacy adopts them.
- 5
Label for the route
A 503B label states “This is a compounded drug” or an equivalent, the facility details, lot, established name, dosage form and strength, compounding and expiration dates, storage, and “Not for resale”, with adverse-event reporting details and directions on the container labelling.
- 6
Prepare for the inspector who will come
A 503B facility is inspected by FDA on a risk-based schedule against cGMP. A 503A pharmacy is primarily overseen by its state board, though FDA can inspect. Run self-inspections against the right standard.
- !Supplying clinics for office use under a 503A licence.
- !Registering under 503B and keeping a pharmacy quality system.
- !Continuing to compound a copy of an approved drug after it leaves the shortage list.
- !Assigning 503B expiry dates without stability data.
How to Choose Between 503A and 503B Compounding: frequently asked questions
Common questions on choose between 503a and 503b compounding.
Can a 503A pharmacy compound ahead of prescriptions?
In limited quantities, where there is a history of valid prescription orders for the drug generated within an established relationship with the patient or prescriber. The compounded drug is then dispensed against a valid prescription for an identified patient.
Does a 503B facility have to compound only sterile drugs?
An outsourcing facility is defined as one engaged in compounding sterile drugs. Once registered, all compounding at the facility must take place in accordance with section 503B.
Is a 503B facility exempt from DSCSA?
Drugs compounded in compliance with section 503B are exempt from section 582, the DSCSA tracing requirements, as well as from adequate-directions labelling and new drug approval. They are not exempt from cGMP.
WHERE NEXT
- DO ITOpen the Compounding Route Assessment (503A or 503B) template →The structure these steps fill in.
- UNDERSTAND ITPharmacy Compounding: 503A and 503B →The principles behind the procedure.
- ALL GUIDESBrowse all 127 how-to guides →
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