Infrastructure for Compounding
“Your plans will be determined by your risk category of compounding, current set-up, budget, and desires for the future.”Joseph Coyne, RPh
One of the challenges to achieving compliance with USP <800> involves building or retrofitting the physical plant. Design, selection, and build of primary and secondary engineering controls are influenced by numerous factors, including compounding risk, institutional setting, and scope of practice.
Infrastructure for Compounding.
Primary Engineering Controls:
All containment primary engineering controls (C-PECs) used for manipulation of sterile hazardous drugs must be externally vented. Sterile HD compounding must be performed in a C-PEC that provides an ISO Class 5 or better air quality, such as a Class II or III biological safety cabinet (BSC) or compounding aseptic containment isolator (CACI). Class II BSC Types A2, B1, or B2 are acceptable. For most known HDs, Type A2 BSCs offer a simple and reliable integration with the ventilation and pressurization requirements of the containment secondary engineering control (C-SEC). Class II Type B2 BSCs are typically reserved for use with volatile components.
A laminar airflow workbench (LAFW) or compounding aseptic isolator (CAI) must not be used for the compounding of an antineoplastic HD. A BSC or CACI used for the preparation of HDs must not be used for the preparation of a non-HD unless the non-HD preparation is placed into a protective outer wrapper during removal from the C-PEC and is labeled to require personal protective equipment handling precautions.
Secondary Engineering Controls:
The C-PEC must be located in a C-SEC, which may either be an ISO Class 7 buffer room with an ISO Class 7 ante-room (preferred) or an unclassified containment segregated compounding area (C-SCA). If the C-PEC is placed in a C-SCA, the beyond-use date (BUD) of all compounded sterile preparations (CSPs) prepared must be limited as described in <797> for CSPs prepared in a segregated compounding area.
ISO Class 7 buffer room with an ISO Class 7 ante-room:
The C-PEC is placed in an ISO Class 7 buffer room that has fixed walls, a HEPA-filtered supply air, a negative pressure between 0.01 and 0.03 inches of water column relative to all adjacent areas, and a minimum of 30 air changes per hour (ACPH).
The buffer room must be externally vented. Because the room through which entry into the HD buffer room; for example, anteroom or non-HD buffer room, plays an important role in terms of total contamination control, the following is required:
- Minimum of 30 ACPH of HEPA-filtered supply air.
- Maintenance of a positive pressure of at least 0.02 inches of water column relative to all adjacent unclassified areas.
- Maintenance of an air quality of ISO Class 7 or better.
An ISO Class 7 ante-room with fixed walls is necessary to provide inward air migration of equal cleanliness classified air into the negative pressure buffer room to contain any airborne HD. A hand-washing sink must be placed in the ante-room at least 1 meter from the entrance to the HD buffer room to avoid contamination migration into the negative pressure HD buffer room.
Containment segregated compounding area (C-SCA):
The C-PEC is placed in an unclassified C-SCA that has fixed walls, a negative pressure between 0.01 and 0.03 inches of water column relative to all adjacent areas, and a minimum of 12 ACPH. The C-SCA must be externally vented. A hand-washing sink must be placed at least 1 meter from C-PEC and may be either inside the C-SCA or directly outside the C-SCA. Only low- and medium-risk HD CSPs may be prepared in a C-SCA. HD CSPs prepared in the C-SCA must not exceed the BUDs described in <797> for CSPs prepared in a segregated compounding area.