Laminar Flow Unit

Perform general operational controls verification testing. 

Operate system throughout the range of operating design specifications or range of intended use. 

Integrity test all HEPA filters with dioctylphthalate (DOP) smoke. 

Measure the average face velocity of each terminal HEPA filter. Measure the average velocity 1 ft above the workspace, exposed product areas, or exposed component areas in all Class 100 laminar flow rooms or areas. 

Verify that system air flows have been balanced to within 10% of design criteria. 

---

Filtered air may be used to purge a complete room, or it m be confined to a specific area and incorporate the principle of laminar flow, which permits operations to be carried out in a gentle current of sterile air. The direction of the airflow may be horizontal or vertical, depending upon the type of equipment being nsed, the type of operation and the material being handled. It is important that there is no obstruction between the air supply and the exposed product, since this may resnlt in the deflection of microorganisms or particulate matter fiom a non-sterile surface and canse contamination. Airflow gauges are essential to monitor that the correct flow rate is obtained in laminar flow units and in complete suites to ensure that a positive pressure fiom clean to less clean areas is always maintained. 

To support the institutional pharmacist in preparing IV admixtures (which typically involves adding one or more drugs to large-volume parenteral fluids), equipment manufacturers have designed laminar flow units, electromechanical compounding units, transfer devices, and filters specifically adaptable to a variety of hospital programs. 

A laminar flow enclosure provides a means for environmental control of a confined area for aseptic use. Laminar flow units utilize HEPA filters, with the uniform movement of air along parallel lines. The air movement may be in a horizontal or vertical direction and may involve a confined area, such as a workbench, or an entire room. Laminar flow modules are suspended above filling lines, vial- and stopper-washing equipment, and other processes to provide an aseptic and particulate-free environment. 

In a plug flow reactor, or along a stream line in the laminar flow unit,... 

Power shutdown is to be simulated by stopping the laminar flow unit and the main air handling unit (AHU) for 30 seconds. 

Make sure that HVAC system and laminar flow units are in operation. 

Notes LFA = laminar flow unit over ampoule filling machine LFV = laminar flow unit over vial filling machine LFCI = laminar flow unit over conveyor (in) LFCO = laminar flow unit over conveyor (out) LFF = laminar flow unit over freeze drying unit. 

Abbreviations used LFA = Laminar Flow Unit over Ampoule Filling Machine LFCI = Laminar Flow Unit over Conveyor (IN) LFF = Laminar Flow Unit over Freeze Drying Unit LFV = Laminar Flow Unit over Vial Filling Machine LFCO = Laminar Flow Unit over Conveyor (OUT)... 

The entire transportation area must be fully covered by laminar flow units. 

A complete visual representation of the manufacturing process in flow chart format should be included. This flow chart should indicate the step in the process, the equipment and materials used, and the room where the operation is performed, and should provide a complete list of the in-process controls and tests performed on the product at each step. The diagram should also include information, including a descriptive narrative, on the methods used to transfer the product between steps (i.e., sterile, SIP connection, sanitary connection, open transfers under laminar flow units, etc.). 

Workbenches, including laminar flow units, and equipment, should be disinfected immediately before and after each work session. Equipment must be of the simplest design possible for the operation being performed. 

Airflow visualization (To verify required airflow patterns) All classes 24 months Tests to demonstrate airflows from clean to dirty areas do not cause cross-contamination uniformly from laminar flow units. Demonstrated by actual or videotaped smoke tests. In accordance with ISO 14644-3 Annex B7 ... 

The precise location of portable units must be defined. Laminar flow units, although creating a protected environment within their confines, may themselves create turbulence and dead air in the room in which they are situated and into which they exhaust. This may create a secondary source of contamination. The airflow patterns around laminar flow units relative to fixed air exit registers, screening, and other equipment in a room cannot be predicted. Empirical evidence from smoke pattern studies is necessary to be confident of their effectiveness. 

In pharmacies a laminar flow unit is used to protect the product against microbiological contamination from the operator. With a cross flow LAF cabinet the HEPA filtered air is directed over the working area to the operator. This type of LAF bench thus cannot be used for operations with hazardous substances (hazardous being defined as any substance with a H statement, so with a hazard class higher than one, see Sect. 26.3.1). It can be used for aseptic preparation processes with closed systems, such as aseptic handling, see Chap. 31. 

For all high-sterility manufacturing operations, class 100 air cleanliness according to U.S. Federal Standard 209A (1966) must be maintained. High-efficiency air filtration and laminar flow units must be installed in packaging areas. Removal of the airborne microbes from the air that feeds the dryers and packaging areas is usually performed by... 

---