Home > USP 797 Compliance > Using Barrier Isolators for Sterile Compounding

Using Barrier Isolators for Sterile Compounding

How these engineering controls meet the new USP Chapter <797> and NIOSH environmental recommendations

Two documents published in 2004 have changed the way compounding facilities prepare, package, and store compound sterile preparations (CSPs):

• USP <797> Pharmaceutical Compounding - Sterile Preparations
• NIOSH's alert for Preventing Occupational Exposures to Antineoplastic and Other Hazardous Drugs in Health Care Settings

USP <797>

USP <797> addresses policies and practices for preparing, packaging, and storing CSPs, and was the first official and enforceable requirement for CSPs. By setting standards, requirements, and procedures for CSPs, USP <797> reduces the potential for contamination caused by an unclean environment, pharmacist error, lack of quality assurance, incorrect beyond-use dating, and other factors. Some specific issues USP <797> address include

• The responsibility of compounding personnel to ensure that CSPs are prepared, stored, dispensed, and distributed safely
• Contamination risk levels
• Procedures to verify the accuracy and sterility of CSPs
• Personnel training and evaluation
• Verification of Automated Compounding Devices (ACDs)
• Environmental quality and control
• Checks and tests of finished preparations before dispensing
• Storage and beyond-use dating
• Product quality and control after the CSP leaves the pharmacy
• Patient or caregiver training so they can store, administer, and dispose of the CSP
• Patient monitoring to track their response to the therapy
• The need for a feedback mechanism so patients and caregivers can report concerns about CSPs
• A quality assurance program that documents CSP policies, processes, and procedures

Ultimately, USP <797> protects patients from harm, injury, and even death. Through USP <797>, compounding facilities can identify where failures could occur during a compounding process and implement methods to control and monitor these critical points.

NIOSH's alert for Preventing Occupational Exposures to Antineoplastic and Other Hazardous Drugs in Health Care Settings

NIOSH's alert addresses the health risks to health care workers and employers who work with hazardous drugs, and to provide them with measures for protecting their health. Health care workers who prepare or administer hazardous drugs or who work in areas where these drugs are used may be exposed to these agents in a variety of ways:

• In the air
• On work surfaces
• In contaminated clothing
• On medical equipment
• In patient excreta
• On other surfaces

Workplace exposures to hazardous drugs can lead to numerous health risks, including

• Health effects such as skin rashes
• Adverse reproductive outcomes (including infertility, spontaneous abortions, and congenital malformations)
• Leukemia and other cancers

The health risk is influenced by the extent of the exposure and the potency and toxicity of the hazardous drug.

To protect workers, employers need to implement administrative and engineering controls and ensure that workers use sound procedures and proper protective equipment when handling hazardous drugs.

Responding to USP <797> and the NIOSH alert

Since the publication of USP <797> and the NIOSH alert, compounding facilities have been working to bring their practices and procedures in line with these new requirements. One solution offered by both documents is the barrier isolator, which can be specifically designed to meet the new requirements.

Barrier isolators are defined as "decontaminated units supplied with HEPA filtered air that provide uncompromised continuous isolation of its interior from the external environment, including surrounding cleanroom air and personnel." In other words, barrier isolators provide a Class 100 environment for product preparation, with work occurring inside a closed, pressurized environment accessible only via sealed gloves that reach into the work area.With barrier isolators, you can obtain cleanroom conditions within a contained workspace.

Barrier isolators protect patients

• Identify where failures could occur during a compounding process
• Implement methods to control and monitor these critical points

Barrier isolators protect patients by reducing the possibility of CSP contamination.

Specific features of barrier isolators that reduce the possibility of CSP contamination include the following:

• Using unidirectional or turbulent airflow to remove contaminants from material
• Using positive air pressure to keep external airborne particles out of the isolator
• Including a pass-through system that isolates the interior of the unit from the room when materials are transferred in and out.

Barrier isolators protect health care workers

NIOSH's alert is aimed at reducing the risk health care workers face when they deal with hazardous drugs. Health care workers can be exposed to hazardous drugs through inhalation, skin contact, skin absorption, ingestion, or injection.

Barrier isolators reduce the risk to health care workers by completely isolating the hazardous material. First, workers use a sealed, sterile, aseptic pass-through chamber to place hazardous materials into the isolator. Then, the hazardous material is placed in a sealed and closed work area that contains all airborne contaminants and sweeps them safely out through an air exhaust system. Workers can view the materials through plastic viewing screens, and access the material only through ports equipped with gloves. In addition, workers can wear double gloves so that if the outer glove is ripped or begins to leak, the inner glove still provides protection.

Can barrier isolators replace cleanrooms?

Many compounding facilities may believe they need to install cleanrooms in order to comply with USP <797> and the NIOSH alert. However, in many instances, barrier isolators can take the place of a cleanroom by providing cleanroom conditions within a contained workspace. Barrier isolators offer several advantages over cleanrooms:

• Workers have no direct with the work area. Instead, they access the work area via a port equipped with sealed gloves. This isolation eliminates the largest source of contamination in compounding - people.
• Barrier isolators take up far less valuable floor space than do cleanrooms and are more economical to install and maintain.
• Workers do not have to fully gown before they begin work, which can save nearly an hour of work time each day.
• Decontamination is easier in the small, contained environment of the barrier isolator.

The one disadvantage of barrier isolators is that they can be uncomfortable to use. However, manufacturers can make isolators more comfortable by including height adjustors and offering variable glove sizes.

Locating barrier isolators for optimum efficiency

You also need to consider where the barrier isolator will be placed. Because barrier isolators are closed systems, they are not as sensitive to their external environment as laminar-airflow equipment. Ideally, however, barrier isolators should be placed within a buffer air quality area with an ISO Class 8 environment.

If you don't have an ISO Class 8 area to house your isolator, you must at least keep the environment as clean and sterile as possible. You want to minimize as much as possible any contamination that could occur as you transfer products into and out of the barrier isolator. Consequently, it is good practice to

• Place barrier isolators in areas with limited personnel access.
• Control the temperature and humidity inside the room where the barrier isolator is placed.
• Implement a regular cleaning and maintenance schedule for the barrier isolator itself and for the surrounding area. For example, floors should be disinfected nightly. Additional cleaning steps are required after preparing products that contain allergenic ingredients, such as penicillin.

Other options for improving cleanliness levels in the area around the barrier isolator include:

• Installing HEPA filters in the ceiling fans
• Replacing ceiling tiles with "cleanroom grade" tiles
• Removing refrigerators, computers, and printers from the compounding area
• Replacing flooring with seamless vinyl floor covering
• Implementing proper housekeeping procedures for cleaning and sanitizing

A look at the A2 Pharmacy Isolator

The A2 Pharmacy Isolator provides an excellent example of a well-designed and engineered barrier isolator that will help compounding facilities meet both the USP <797> and NIOSH requirements. The A2 Pharmacy Isolator -

• Provides the same level of air quality a cleanroom does, while taking up less space and being more cost-effective to operate.
• Uses a turbulent airflow system to add HEPA-filtered air to the system, which then dilutes contaminants. The contaminants are then safely moved out through the air exhaust system
• Includes both positive and negative air pressure options to keep contaminants from the surrounding environment out of the barrier isolator.
• Is constructed of one piece of long-lasting stainless steel with rounded corners for easy sterilization.
• Includes an air-lock transfer chamber with a ventilation system. When you place materials in this chamber, the ventilation system cleans the air in the background chamber up to class 100 quality.
• Is easy to clean and sanitize. All inside surfaces can be easily reached from the glove ports for routine sanitization, and the low height and roller base frame make the external surface of the isolator easy to clean.
• Has electronic controls for adjusting the height, making the A2 Pharmacy Isolator comfortable to use.
• Has other electronic controls that open and close the doors and monitor negative and positive pressure, the air change rate, the integrity of vacuum systems, the electrical supply, and leaks.
• Includes an Uninterruptible Power Supply (UPS), making it safe and reliable.

The A2 Pharmacy Isolator can also be custom-designed to meet the unique and individual needs of your facility.

Summary

USP <797> Pharmaceutical Compounding - Sterile Preparations seeks to protect patients by reducing the possibility of microbial contamination that could occur when preparing, packaging, and storing CSPs. NIOSH's alert for Preventing Occupational Exposures to Antineoplastic and Other Hazardous Drugs in Health Care Settings seeks to protect health care workers by reducing their exposure to hazardous materials. By choosing a well-engineered barrier isolator such as the A2 Pharmacy Isolator for your facilities that compound CSPs, you will be able to meet the requirements of both of these documents.