USP 797 Sterile Compounding Standards for Pharmacy Techs

USP 797 Sterile Compounding: What Pharmacy Technicians Need to Know

USP General Chapter 797 establishes the minimum standards for compounding sterile preparations (CSPs) in pharmacy settings. Whether you work in a hospital, compounding pharmacy, or home infusion facility, understanding USP 797 is essential for patient safety and PTCB exam success. The revised chapter, which took effect in November 2023, introduced significant changes that every pharmacy technician should understand.

Purpose and Scope of USP 797

USP 797 exists to prevent patient harm from contaminated, improperly prepared, or incorrectly stored sterile preparations. The chapter applies to all facilities and persons that prepare CSPs, including hospitals, compounding pharmacies, physician offices, and other healthcare settings. The standards cover personnel training, facility design, environmental monitoring, and quality assurance procedures.

Sterile preparations include intravenous (IV) solutions, ophthalmic preparations, injections, and any other dosage forms that must be free from microbial contamination. Even simple tasks like adding a drug to an IV bag fall under USP 797 requirements.

Cleanroom Classifications and Design

USP 797 specifies requirements for the physical environment where sterile compounding takes place:

Primary Engineering Controls (PECs)

Laminar Airflow Workbench (LAFW): Provides ISO Class 5 air quality using horizontal or vertical HEPA-filtered airflow. Used for most sterile compounding activities.
Biological Safety Cabinet (BSC): Required for compounding hazardous drugs. Provides both product and personnel protection.
Compounding Aseptic Isolator (CAI): Enclosed unit providing ISO Class 5 environment. Can be placed in less controlled areas under certain conditions.

Secondary Engineering Controls (SECs)

Buffer area: ISO Class 7 environment where the PEC is located. Positive pressure relative to adjacent areas (negative pressure for hazardous drugs).
Ante-area: ISO Class 8 environment serving as a transition space between unclassified areas and the buffer area. Garbing and hand hygiene occur here.

Garbing and Hand Hygiene Procedures

Proper garbing is critical to preventing contamination. USP 797 requires specific garbing procedures that pharmacy technicians must follow in the correct order:

Remove outer garments, jewelry, and personal items before entering the ante-area
Put on dedicated shoes or shoe covers
Perform hand hygiene with soap and water for at least 30 seconds
Don hair cover, face mask, and beard cover (if applicable)
Put on a clean, low-shedding gown
Apply alcohol-based hand sanitizer (let dry completely)
Don sterile, powder-free gloves before entering the buffer area
Sanitize gloves with sterile 70% isopropyl alcohol before and during compounding

Gloves must be routinely sanitized during compounding, especially after touching non-sterile surfaces. Garb must be replaced if it becomes visibly soiled or compromised.

Beyond-Use Dating (BUD)

Beyond-use dating is one of the most heavily tested USP 797 topics on the PTCB exam. The revised chapter categorizes CSPs and assigns maximum BUDs based on compounding conditions:

Category 1 CSPs

Compounded in a PEC that does not meet all Category 2 requirements. Maximum BUDs are significantly shorter:

Room temperature: 12 hours
Refrigerated (2-8 degrees C): 24 hours

Category 2 CSPs

Compounded in facilities meeting all USP 797 requirements for cleanroom standards, environmental monitoring, and personnel training:

Room temperature: 4 days
Refrigerated: 10 days
Frozen (-25 to -10 degrees C): 45 days

Personnel Training and Competency

USP 797 mandates that all personnel involved in sterile compounding complete initial and ongoing training. Key requirements include:

Didactic training covering aseptic technique, microbiology basics, and facility procedures
Practical skills assessment including media fill testing (aseptic technique validation)
Gloved fingertip sampling to verify proper hand hygiene
Initial competency assessment before independently compounding
Ongoing competency assessments at defined intervals

Media fill testing requires personnel to perform simulated compounding using growth media instead of actual drugs. The media is then incubated to check for microbial growth, which would indicate a break in aseptic technique.

Environmental Monitoring

Facilities must conduct regular environmental monitoring to verify cleanroom conditions. This includes viable air sampling, viable surface sampling, and nonviable particle counting. Results exceeding action levels require investigation and corrective action. Temperature monitoring of storage areas and PECs must be performed and documented.

Cleaning and Disinfection

USP 797 specifies cleaning and disinfection requirements for compounding areas. Work surfaces must be cleaned before each compounding session with sterile 70% isopropyl alcohol. Floors, walls, and ceilings require regular cleaning with appropriate agents. A sporicidal agent must be used at least monthly on all cleanroom surfaces.

PTCB Exam Focus Areas

For the PTCB exam, concentrate on beyond-use dating categories, garbing order, cleanroom ISO classifications, and the difference between Category 1 and Category 2 CSPs. Know that ISO Class 5 is required at the direct compounding area, ISO Class 7 for the buffer area, and ISO Class 8 for the ante-area. Understanding these fundamentals will help you answer USP 797 questions confidently on exam day.