These special devices may be considered in 3 categories: Number 1, the device to protect the handler of the vial or the ampoule Number 2, devices to protect the operator during preparation Number 3, devices to protect the administrator during administration of the cytotoxic drugs to the patient In the late 1990s, several study indicated that vials and ampoule delivered from pharmaceutical company may be contaminated on the outside with the cytotoxic drug. In some cases, contamination was detectable in up to 30 to 50% of the vials examined. It is strongly recommended that cytotoxic drug vials be enclosed in plastic coating in order to contain any possible contamination on the outside of the vial.
This plastic coating should also cover the bottom of the vial. Many manufacturers now supply cytotoxics in plastic shrink wrap for this purpose. Some manufacturers supply their cytotoxic agents encased in specially designed molded plastic container to contain any possible contamination, and also to protect against any shock during transport. It is the responsibility of pharmaceutical manufacturer to guarantee that the external surface of drug vial are free of contamination. One objective way to ensure commitment to deliver contamination-free products is to mandate analysis by an independent laboratory, detailing the amounts of product on the outer surface of the first, middle, and last vial,ampoule of the batch prepared.
Pharmacists should favor manufacturers who take the problem seriously and are prepared to work to ensure contamination-free vials. Numerous studies have shown that aseptic manipulation using a classic syringe and needle technique almost universally result in contamination. Droplets, leakage from vial stopper after multiple punctures, and aerosol generation resulting from increased pressure inside drug vials have also been observed. In cytotoxic reconstitution both microbiological contamination and hazardous drug containment are concerns. The NIOSH definition is therefore the most comprehensive and complete. Closed System Drug Transfer Device is a drug transfer device which mechanically prohibits the transfer of environmental contaminants into the system and escape of hazardous drugs or vapor concentrations outside the system
CSTDs fall into 2 categories: hose that develop system that are closed and those that use aircleaning technology to limit the flow of contaminants from within a vial to the environment they are called aircleansing systems. Typically, systems of the second type incorporate an activated carbon filter or hydrophobic filter to help reduce the outflow of contaminants. Very importantly, CSTD are supplemental engineering controls that are intended for use with other safety systems, such as Biological Safety Cabinets and containment isolator. CSTD selection must be a collaborative process to ensure the device chosen is workable for both the pharmacy and nursing teams.
Considerations when evaluating CSTDs include ease of use, the number of components required, the amount of sculpt space required to store the devices, risk of repetitive stain injure, cost, and clinical effectiveness. Corrosive chemotherapy agents may be incompatible with the rubber used in the closed system. In these cases, the CSTD should not be used with this product during preparation or administration. Please check with your CSTD vendor for specific information on incompatibility. Vials with small neck diameters may also be an issue; although CSTD manufacturers provide vial access device that allow access to small vial neck diameter, it is critical to verify that these devices create a secure connect. There are several types of Biological Safety Cabinets.
They are classified into 3 main classes, class I, class II and class III. A Class I Biological Safety Cabinets is designed to protect only the operator and the environment and must NOT be used for the preparation of sterile products and will not be described here. Class II Biological Safety Cabinet is a ventilated Biological Safety Cabinet that protects the operator, the product and work environment. A Class II Biological Safety Cabinet has an open front inward airflow for personnel protection, downward HEPA-filtered laminar airflow for product protection and HEPA-filtered exhausted air for protection of the environment. There are 4 sub classifications of the Class II Biological Safety Cabinet. They are A1, A2, B1, and B2.
Class II A cabinets are not recommended as they are not suitable for the manipulation of volatile toxic chemicals, this infer to A1 cabinets, or for only minute quantities of volatile chemical, this refer to A2, unless special containment device. For example, leakproof, airtight devices are used during the preparation Class II B1, it has inflow air partially recirculated or preferably Class II B2 which is having total exhaust are suitable for cytotoxic preparation. Some countries, for example, Australia, require the inclusion of an activated carbon filter fitted downstream of the exhaust HEPA filter to counter the problem of cytotoxic drugs which may vaporize and pass through the HEPA exhaust filter.
However, concerns exist over the effectiveness of activated carbon in removal of these volatile substances. These filters absorb the vapor in a dynamic equilibrium with the surrounding. A Class III Biological Safety Cabinet is a totally enclosed vented cabinet of gas tight construction. Operations are conducted through attached gloves and observed through a non-opening view window. This Biological Safety Cabinet is maintained under negative pressure and air is drawn into the cabinet through HEPA filters. The exhaust air is treated by double HEPA filtration. Passage of material in and out the cabinet is generally performed through a double door pass through box. Class III Biological Safety Cabinets have the advantage that there is a physical barrier between the product and the handler.
Class III Biological Safety Cabinets are an intermediate configuration between a Class II BSC and an isolator. Compounding aseptic isolator is a form of barrier isolator specifically designed for compounding pharmaceutical ingredients or preparations. It is designed to maintain an aseptic compounding environment within the isolator throughout the compounding and material transfer processes. Air exchange into the isolator from the surrounding environment should not occur unless it has first passed through a microbially retentive filter. Physical monitoring must be performed on a regular basis. The aim is to monitor whether the Biological Safety Cabinet is performing to specification. A series of physical tests must be carried out upon installation, whenever changes are made to the installation.
For example, replacement of a HEPA filter, and on a regular basis as a preventive measure. Physical tests include checking the integrity of the HEPA filters which is called DOP test, checking the airflow velocity, checking the air circulation and also called smoke test, checking the airflow retention, checking the pressure, checking particulate contamination, checking temperature and humidity, and also a noise test. The frequency with which these tests should be conducted vary according to the test. The leak test, the test only for Biological safety Cabinets Class III and Isolator only, and the smoke test should be performed monthly. Air velocity and particulate count tests should be done every three months, and the DOP test every 6 to 12 months.