503A vs. 503B

Veterinary professionals have more options than ever to turn to for compounded patient drugs. More options means more complexity and questions for both individual patient orders and in-house bulk stock.

Knowing the differences between 503A compounding pharmacies and 503B outsourcing facilities, and the benefits of each, ensures you’re providing your patients with the highest standard of care. 

Use our chart below for a quick review of the basics, explore our blogs, or find even more in our full library of resources!

Traditionally Compounded and 100% Manufactured Veterinary Medicines

Both traditional 503A compounding pharmacies and 503B outsourcing facilities serve as important partners for veterinary practices.

  • 503A: prepared patient-specific prescriptions for your individual patients
  • 503B: standardized and tested medications that serve the needs of many of your patients

They each operate with key differences that impact your patient care and influence treatment plans.

Two Divisions, One Focus:

Improving patient outcomes with medication you trust.

one vs many

Stokes Healthcare has prepared medications for your individual patients since 1975 through Stokes Pharmacy. Recognizing the evolving needs of veterinary practices as regulations and laws changed, including GFI 256 and USP Guidelines, we expanded to include Epicur Pharma to serve the needs of many of your patients with standardized and tested bulk medications.

The chart below reviews some of the key differences between 503A pharmacies and 503B outsourcing facilities, and how each of our divisions can support your practice and patients. 

epicur logo



Type of Facility

Traditional Compounding Pharmacy

FDA Registered Facility

Product Purpose

Customized prescriptions for individual patients

Manufactured drugs in bulk quantities for hospitals

Regulatory Oversight

State Boards of Pharmacy



USP (United States Pharmacopeia)

cGMP (current Good Manufacturing Processes)

Product Dating

Beyond-Use Date (limited)

Expiration Date (proven)

FDA inspections

For cause (approx. 3k compounding pharmacies)

Random inspections (approx. 69 facilities)

More 503A and 503B Resources

Ready to start your order?

Through each of our divisions, Stokes Healthcare can support your practice’s prescription and bulk order needs.

Epicur’s manufactured products are available for individual patient prescriptions through Stokes Pharmacy. As an FDA Registered 503B Outsourcing Facility with a set process for developing each drug, Epicur has a specific product list.

Download our product lists:

If you’re looking to order a customized prescription for a specific drug, strength, or dosage form, that is not available through Epicur Pharma, Stokes Pharmacy can help! 

For existing iFill accounts, login and order:

To refill a specific patient prescription:

Are you a new partner? Start your account online or call us at 888-508-5032.

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