Drugs are considered hazardous when they bind to or damage DNA, such as alkylating agents. Antineoplastic drugs, some antivirals, antibiotics, and bioengineered drugs interfere with cell growth or proliferation and DNA synthesis. The non-selective actions of these drugs can disrupt the growth and function of both healthy and diseased cells, resulting in toxic side effects for treated patients and the pharmacists compounding them who are inadvertently exposed.
The USP 800 standard aims to prevent the exposure of hazardous drugs to the pharmacists, through inhalation or direct skin contact during preparation and handling activities, including:
- Transferring hazardous drugs from one container to another, and reconstituting or manipulating them.
- Withdrawal of needles from drug vials.
- Expulsion of air from a drug-filled syringe.
- Drug handling practices, such as mixing, crushing, reconstituting, aerosolizing, and blending of drugs.
- Handling and disposal of needles or sharps.
To comply with USP 800, the compounding must be performed inside a PEC (Primary Engineering Control) or “Hood”, placed inside a SEC (Secondary Engineering Control) or “Room”, to ensure operator safety and product sterility as needed. The PEC is typically a Biosafety Cabinet (BSC), and the SEC is an ISO Class 7 Cleanroom. An ISO Class 5 is recommended, with 0.1 to 0.3 “WG negative pressure
For USP 800 Non-Sterile drugs, a Class I Biosafety Cabinet (BSC) or Containment Ventilated Enclosure (CVE) is typically used. This cabinet draws room air away from the operator to prevent exposure to hazardous drugs being compounded inside the work zone, then exhaust the air through HEPA filter(s) on top. The exhaust air needs to be ducted outside the building, but if there are no volatile chemicals being released in the work zone, double HEPA filters that can exhaust the air back into the room is allowed in lieu of costly ducting.
The cabinet is typically placed inside an ISO Class 7 SEC:
For USP 800 Sterile drugs, a Class II Biosafety Cabinet (BSC) is typically used. In addition to having inflow to protect the user, this cabinet also has HEPA-filtered downflow to protect the compounded drugs from outside contaminants to keep them sterile. The exhaust air needs to be ducted outside the building via an exhaust collar. If there are no volatile chemicals being released in the work zone, then a secondary exhaust module consisting of a second HEPA filter and a booster blower can be used to exhaust the air back into the room.
This cabinet is typically placed inside ISO Class 7 SEC with ISO 7 Ante room:
The SEC or Cleanroom also needs an air shower to remove particles attached to the operator’s gown upon entering, and a pass box to transfer the compounded drugs from inside the clean room into the administrative room outside.
