skip to Main Content
Careers         Contact Us         877-550-5059

503A vs. 503B: Pharmacy Designations & Their Significance


For a very long time, humans have battled with the ravages of the natural world in a multitude of ways. During the earliest eons of our existence, the only real way that people had to fight off illnesses was through their own immune systems. But this came at a disadvantage, which was that not everyone had the same level of immunity. What would happen instead is that while most of the people survived their illnesses, others had succumbed to it. Biologists such as Charles Darwin referred to this as “The Survival of the Fittest”.

With the passage of time, our species discovered that our immune systems are not the only defenses we have. As we began to explore the world around us, we figured out that the natural world contained an abundance of naturally occurring chemicals that could help fight off various diseases. Over the course of thousands of years, this developed into a science of its own with labels such as Herbal Medicine, Ayurveda, etc.

The greatest advantage came with the advent of modern scientific discoveries and a better understanding of the world around us. This was the beginning of the world’s pharmaceutical and chemical industry, which greatly increased our ability to recover and maintain health unlike any other period in human history. It became one of the fastest growing industries in the world as more people gained better access to healthcare services all across the planet.


It was here that the dilemma began. Due to the need to maintain quality, standardization, and more, laws were passed to ensure that the pharmaceutical industry was properly regulated in an economy. The US FDA (United States Food & Drug Administration) is a governmental agency that has been established for protecting the health of Americans with respect to food and drugs. This is where the concept of both 503A and 503B Pharmacy designations came into fruition. These legal classifications were given by the US FDA to different classes of drugs based on certain pre-assigned criteria.

These are used by governmental agencies to regulate pharmacies where medications are manufactured for consumption in the market.


How the two designations came about span several years. Given the complex history of how the course of events unfolded in the United States, it is best to link the major tragedies that took place which led to the creation of these two designations.

The triggering incident took place in 2012 during a meningitis outbreak where it was discovered that medical contamination led to the deaths of 76 people and infected nearly 800.[i] Patients were administered contaminated steroid injections that were manufactured and marketed by the New England Compounding Center located in Framingham, Massachusetts. The FDA intervened and created the two categories by which medications would be classified.


The two categories of classification are essentially a way by which the US FDA regulates medications through categories of oversight measures. These categories are not related to the drugs themselves but rather to regulate the facilities in which the medications are prepared. Furthermore, both categories are specifically related to compounded medications as opposed to generalized ones.

Compounded medications are customized according to the specific prescriptions of medical practitioners versus generalized medications that are released for mass consumption. It involves the mixing of various ingredients at varying concentrations based on the exact need of patients.

The two pharmacy classifications described below should help to better understand the concepts:

  • 503A COMPOUNDING PHARMACIES: These are facilities where medications are prepared for domestic consumption at a microeconomic level. They are allowed to manufacture medications in small batches and deliver the same to individuals, local medical centers, and other facilities. They are not allowed to produce medication by means of mass-production that enables a lowering of per unit costs. These facilities can sell the medications with or without any prescription, depending on local laws.
  • 503B COMPOUNDING PHARMACIES: These are large-scale facilities which manufacture in bulk for office use alone. They cannot sell medications that are administered or provided to patients outside office premises. They prepare the required medications in large batches, which in turn can help reduce per unit costs of required medications.


  1. REGULATORY COMPLIANCE- 503A facilities are required to comply with USP <795> and <797> and comply with state boards of pharmacy regulations. 503B facilities are required to comply with USP <795> and <797>, while at the same time also complying with 21 CFL Part 210 and 211 (cGMP) guidelines.
  2. REGULATORY COMPLIANCE – 503A facilities are required to dispense human sterile medications as patient-specific. No such requirements exist for 503B facilities.
  3. ENVIRONMENTAL MONITORING – 503A facilities require environmental monitoring and audits every 6 months. 503B facilities require monitoring to be done on a ‘per production’ shift in the ISO5 primary compounding areas as well as weekly audits in the secondary compounding areas (i.e. ISO7 and ISO 8 facilities).
  4. MEDICINE QUALITY REVIEW – 503A are free to conduct their own reviews regarding their work. 503B facilities are required to have an independent entity do the review.
  5. FINISHED PRODUCT DATING- 503A require the finished product to be labeled with ‘Beyond Use Dating’ or (BUD) based on available medical literature. 503B facilities must have the same done according to scientifically tested specifications based on factors such as time, humidity, and temperature levels.
  6. DRUG COMPOUNDING – 503A facilities may compound drugs belonging to bulk drug substances Category 1, drugs with USP or NF monograph, and the drugs approved by the Secretary. 503B facilities are allowed only to compound drugs from bulk drugs substances Category 1.
  7. REGISTRATION REQUIREMENTS – 503A facilities are required to get themselves registered with each State Board of Pharmacy as well as the DEA. 503B facilities are required to do the same in addition to registering themselves with the FDA. A report of their product list must be submitted to the FDA biannually.

Both facilities play an equally important role in the healthcare industry, albeit at different levels. It shouldn’t be mistaken that one is more important than the other, as each has an important role to play in the larger economy.

[i] Richer, Alanna Durkin (2018, January 31). Pharmacist in Meningitis Outbreak Gets 8 Years in Prison. Associated Press. Retrieved from

Back To Top