Guest Column | January 22, 2018

Microbial Expectations For 503B Compounding Pharmacies

By Crystal M. Booth, PSC Biotech

Pharma Lab Gloves

Compounding pharmacies come in many different shapes and sizes. They can consist of a pharmacist creating a drug under a doctor’s prescription or they can be pharmacy-type facilities that compound drugs and sell them like a manufacturer. Sporadic and serious infection outbreaks have been linked to compounding pharmacies outside of the hospital setting.1 These problems date back to as early as 1976.2 Despite attempts by the United States Pharmacopeia (USP) to make compounding safer, problems still occur.

The Drug Quality and Security Act of 2013 includes a category of compounders known as outsourcing facilities.3 According to section 503B of the Food Drug and Cosmetic Act (FD&C Act), outsourcing facilities are required to comply with all current good manufacturing practices (cGMPs) and regulations regarding insanitary conditions.3 Many regulatory observations are written for the failure to follow cGMPs and insanitary conditions.2 This article highlights some of the microbial expectations for 503B compounding pharmacies.

Preventing Contamination In Compounding Facilities

503B compounding pharmacies are required to adhere to the same microbial regulations and expectations as aseptic pharmaceutical manufacturers. The FDA recommends that compounding facilities that produce sterile drugs routinely perform the following:

  • Environmental monitoring, including nonviable airborne particulate sampling, viable airborne particulate sampling, personnel sampling (including glove fingertip sampling), surface sampling (including but not limited to equipment, work surfaces, and room surfaces)4
  • Media fill studies mimicking aseptic production operations4
  • Certify the ISO 5 area every six months, including smoke studies.4
  • Measure pressure differentials between the different adjacent classified areas.4

Contamination prevention should be thought of in a holistic manner, from the beginning to the end of the process, because microorganisms are present in most habitats. This includes items like supplier management, shipping and receiving, sampling and testing of components and raw materials, facility design, personnel, and environmental and utility monitoring. One cannot rely on the sterility test alone as it does not verify an entire lot of product is sterile. Sterility assurance needs to be built into the manufacturing process.

Humans are the primary source of contamination in a cleanroom. Other common sources include the air, surfaces, and water. Microorganisms may be transferred directly (e.g., touching a surface with a contaminated object) or indirectly (e.g., distributed through the air).5 Monitoring for microbial contamination and identifying any recovered isolates can help detect contamination sources and establish any corrective actions.

Proper design of facilities also helps control microbial contamination. Regulatory requirements for facility design and cleanroom classifications are found in multiple guidance documents, including the Annex 16 and the Code of Federal Regulations (CFR).7 These regulations require certain cleanliness levels in the state of operation, adequate space, and proper material/personnel flow to prevent contamination or mix-ups. Furthermore, 21 CFR 211.42 requires the following regarding facility design for aseptic processing:

  • (i) Floors, walls, and ceilings of smooth, hard surfaces that are easily cleanable;
  • (ii) Temperature and humidity controls;
  • (iii) An air supply filtered through high-efficiency particulate air filters under positive pressure, regardless of whether flow is laminar or nonlaminar;
  • (iv) A system for monitoring environmental conditions;
  • (v) A system for cleaning and disinfecting the room and equipment to produce aseptic conditions;
  • (vi) A system for maintaining any equipment used to control the aseptic conditions.3

There are different classifications of cleanrooms. Annex 1 uses grades, i.e., Grade A, Grade B, Grade C, and Grade D. Grade A is considered the cleanest area.1 ISO 14644-1 uses a similar gradient (ISO 5, ISO 6, ISO 7, and ISO 8), where the ISO 5 area is the cleanest classified area.8

Within the cleanrooms, high-efficiency particulate air (HEPA) filters are used to treat the air to decrease the potential of microbial and particulate contamination. If the HEPA filters are leaking or the filters and/or the returns are blocked, the HEPA filters will not function as intended. Air pressure or air exchange rates need to increase as the cleanroom classifications increase. This means that the inner core (ISO 5/Grade A areas) should have the highest number of air exchanges and the highest air pressure when compared to the surrounding areas. Positive air pressure cascades help to keep microbial ingress under control.

Keep Cleanrooms Clean

Controlling microbial ingress into the cleanroom is a critical concern for the entire cleaning and disinfection process.9 Components, personnel, carts, tanks, tools, cleaning supplies, and instruments that are transferred into the clean area should be clean and free of contamination. Gross contamination is easier to prevent than to correct.

Cleaning is the first step of the cleaning, disinfection, and/or sterilization process. Proper cleaning is important for several reasons:

  • Dirt may physically prevent the disinfectant from encountering microorganisms.
  • Chemical residues could potentially react with and inactivate disinfectants.
  • Difficult to reach surfaces may not be cleaned properly.

Surfaces should be smooth and easy to clean. Porous surfaces can harbor microorganisms, interfere with microbial recovery, and interfere with disinfection efforts. Porous surfaces can make it difficult to recover microorganisms during environmental monitoring and difficult to destroy the microorganisms during disinfection. For this reason, certain materials, such as wooden pallets or cardboard, may be prohibited from entering the cleanrooms.9 In addition, corrosion, rust, and pitting of materials should be avoided.

Once the surfaces are properly cleaned, they can be disinfected. The aim of disinfection is to reduce viable contamination. It is important to note that disinfectants must be qualified.10 Multiple FDA Forms 483 have been written in this regard. The qualification study helps to establish the appropriate concentrations of disinfectants and the effective wet contact time. If disinfectants are not properly prepared, handled, applied, or used, their effectiveness to destroy microorganisms can be compromised. In addition, sporicidal agents should be rotated into the cleaning and disinfection program.10

Another important program to prevent contamination is the material and personnel transfer program. Materials must be properly disinfected and transferred through dedicated pathways to prevent the ingress of microorganisms. Established transfer methods may include:

  • Directly sterilizing items into an area (e.g., double-door autoclave)
  • Using multiple bags and removing the outer bag during the transfer to a cleaner classified area
  • Using chemical disinfection during the transfer process in a material airlock.

The material and personnel transfer program also establishes gowning procedures and hygiene requirements that personnel must follow to enter cleanrooms. Personnel must follow established process flows and only enter and exit the cleanroom through dedicated paths to avoid cross contamination.

Water and excessive moisture are also potential contamination sources.11 Nonsterile water should not be used to clean classified areas and water sources should kept far away from the aseptic (ISO 5) areas.11 Stagnant water or excessive moisture can create the perfect habitat for microorganisms. Humidity in the cleanrooms should be controlled so that moisture does not condense and collect in the cleanrooms. It is important to clean excessive water off the floors, fix any leaks promptly, and avoid dead legs in water systems. Considerations for microbial and chemical monitoring of water systems are discussed in USP <1231> Water for Pharmaceutical Purposes.

According to 21 CFR 211.113(b): “Firms must follow appropriate written procedures designed to prevent microbiological contamination of drug products claiming to be sterile.” Analyzing trends in environmental monitoring and utility data aids in evaluating the effectiveness of the procedures for preventing contamination and the state of control of the facility. Trending also helps facilities to be proactive, establish alert limits, learn the flora of the facility, and to provide seasonal fluctuations and historical data.

Expected action levels for environmental and utility monitoring are provided in multiple guidance documents. These documents include USP <1116>, Annex 1, Annex 18, ISO 14464-1, USP <1231>, and the Water Monographs (e.g., Water for Injection) to name a few. Alert levels should be properly established based on the process capabilities of the facility. This can be accomplished by using statistical analyses of the trend data. Alert levels should be used as an early detection tool to monitor the state of control of the environment or utility system.

Drug components (e.g., drug substances, excipients, containers, and closures) are other potential microbial sources that should be tested and monitored. If the components are not sterile, they can be terminally sterilized or filter sterilized.11 Containers and closures must be nonreactive to the product formulation, sterile, and pyrogen-free. Every sterilization and depyrogenation process needs to be validated.11 In addition, the storage method that is used must also ensure the sterility of the drug components.11

Equipment and supplies should have smooth, cleanable surfaces and should be cleaned with sterile, effective disinfectants and tools that do not leave a residue.11 Unnecessary equipment should not be stored in ISO 5 areas.11 Because equipment in motion can generate particles, ISO 5 areas should be qualified in the state of operation.11

One of the most successful processes in controlling microbial contamination is engineering to remove people from the process. Two successful inventions are isolator systems and reduced access barrier systems (RABS).

Isolator systems are fully enclosed with dedicated air, and they provide the highest level of protection. The inside of the isolator can be decontaminated with vaporized hydrogen peroxide, and since the system is self-contained, the surrounding background room can be downgraded and operators don’t have to be fully gowned.

RABS can be installed on existing machines. They are typically rigid transparent walls with glove ports that separate the filling line from the surrounding area. Operators must be gowned in full aseptic garb.

Train Personnel In Aseptic Practices

The primary purpose of cleanroom gowning is to protect the products and the processing environment from human contamination.12 Cleanroom gowning greatly reduces the microorganisms released by personnel.5 All personnel should be properly gowning qualified before entering the cleanroom, and the qualification should be performed by a trained analyst. The degree of gowning should get more complex as the cleanroom grades increase.

In addition to being properly gowning qualified, personnel entering the cleanroom should practice good hygiene (i.e., daily showering, removing makeup and jewelry, washing hands prior to gowning, and not entering the cleanroom in the event of illness or compromised skin).13 Non-linting cleanroom scrubs that cover as much skin as possible should be used as the inner-suit before gowning.13 All uniform components should be sterile and nonshedding.13 Aseptic gowning practices should be used to don the uniform components, including the nonpowdered, sterile gloves.13 Once properly gowned, no skin or hair should be exposed in the cleanroom.13

Thorough training in aseptic techniques is required for ISO 5 areas. Personnel must maintain high standards each time they deal with sterile product.13 Some aseptic technique concepts include:

  • Never breaking “first air”
  • Not touching sterile items with nonsterile items
  • Not exposing sterile items to nonsterile environments
  • Using clean/sterile equipment and components
  • Using sterile gloves and frequently sanitizing hands
  • Using slow, deliberate movements
  • Not talking excessively or shouting
  • Not interfering or blocking the ISO 5 airflow


There is a history of sporadic and serious infection outbreaks linked to 503B compounding pharmacies, also known as outsourcing facilities. Outsourcing facilities must comply with cGMPs and avoid insanitary conditions. Thus, the regulatory microbial expectations regarding 503B compounding pharmacies mimic the regulations of traditional sterile parenteral manufacturers.

Sterility assurance should be built into the manufacturing process, and microbial contamination prevention should be regarded in a holistic manner.

SOPs should be established, aligned, and consistently followed throughout the facility. Some areas of focus for microbial prevention include aseptic gowning; aseptic technique; personnel and material flow; cleaning and disinfection procedures; policies impacting sanitary conditions; environmental, personnel, and utility monitoring programs; controlled entry into manufacturing and laboratory areas; validated equipment; and validated methods.

It is important to remember that sterility testing is a quality control test and does not guarantee the sterility of an entire lot of product. Assurance of sterility is comprised from the summation of the proper aseptic behaviors, processes, and programs that are in place that prevent contamination.


  1. Staes, C., Jacobs, J., Mayer, J., and Allen, J. (2013). “Description of outbreaks of healthcare associated infections related to compounding pharmacies, 2000-2012”. American Journal of Health-System Pharmacy: AJHP: Official Journal of the American Society of Health-System Pharmacists, 70(15), 1301–1312.
  2. Sutton, Scott (2013). “GMP Compounding Pharmacies”. American Pharmaceutical Review. April 30, 2013.
  3. FDA, Center for Drug Evaluation and Research (CDER), Outsourcing Facility Information, September 2017.
  4. FDA, Draft Guidance for Industry – Insanitary Conditions at Compounding Facilities. August 2016.
  5. Brandes, Ruven. Aseptic Processing: Qualification of Personnel, Mass & Peither AG-GMP Publishing, April 12, 2012.
  6. European Commission. EudraLex "The Rules Governing Medicinal Products in the European Union", Volume 4, EU Guidelines to Good Manufacturing Practice, Medicinal Products for Human and Veterinary Use, Annex 1 – Manufacture of Sterile Medicinal Products, November 25, 2008.
  7. CFR – Code of Federal Regulations Title 21. Accessed on October 30, 2017.
  8. ISO 14644-1:2015 — Cleanrooms and associated control. led environments, Part 1: Classification of air cleanliness by particle concentration.
  9. USP <797> Pharmaceutical Compounding – Sterile Preparations.
  10. PDA (2015), Technical Report No. 70 – Fundamentals of Cleaning and Disinfection Programs for Aseptic Manufacturing Facilities.
  11. Deveau, Ian F. “Understanding cGMP Requirements and Insanitary Conditions”. 12th Annual PDA Global Conference on Pharmaceutical Microbiology, October 17, 2017.
  12. Ljungqvist, B. and Reinmuller, B. “Aseptic Production, Gowning Systems, and Airborne Contaminants”. Data and Review, May 2005.
  13. FDA Office of Regulatory Affairs (ORA). Pharmaceutical Microbiology Manual 2014, Version 1.1, ORA.007, April 25, 2014.

About the Author:

Crystal M. Booth is president of Azzur Labs, LLC. She has over 19 years of experience in pharmaceutical microbiology, working in quality assurance, CDMOs, R&D, and quality control laboratories, including startup companies. During her career, she has developed and validated methods for antibiotics, otic products, topical creams, topical ointments, oral solid dose products, oral liquid dose products, veterinary products, human parenterals, vaccines, biologics, aseptically filled products, and terminally sterilized products. Those methods include microbial limits testing, bacterial endotoxins testing, particulate testing, sterility testing, pharmaceutical water system validations, EM programs, surface recovery validations, disinfectant efficacy studies, minimum inhibitory concentration testing, antimicrobial effectiveness testing, hold time studies, and various equipment validations. Booth earned her bachelor’s degree in biology from Old Dominion University and her master’s in microbiology from North Carolina State University.