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suits. If this process is not performed correctly, contaminants can enter the cleanroom on gowns, gloves, over- shoes, etc. The garments worn in the cleanroom must fit well, so that skin Figure 1: Typical settle particles are retained within the suit, and contact plates and be made of a material that does not shed fibres or particles. Aseptic tech- niques should be taught in order that Key to any cleanroom or aseptic operation is a planned personnel do not contaminate gloves after, for example, touching their faces. programme of monitoring. Colin Booth, vice-president Water is a potential vector of conta- mination, enabling organisms to spread science and technology at Oxoid, outlines the basis for a in ways they cannot on solid surfaces. Regulations state that there should be microbial monitoring strategy no water outlets in cleanroom areas; however, water is used in cleaning and here it is not possible to good cleanroom design; effective air is probably the most commonly used terminally sterilise, to be handling; cleaning and disinfection; raw material in manufacture. Water- confident of producing a staff training for adherence to aseptic based fluids must be sterilised before sterile product manufac- techniques; properly fitted cleanroom they are taken into the filling rooms. W turers of parenteral drugs gowns; sterilisation of materials As water is also used in cleanroom sup- must ensure that a robust environ- brought into the aseptic environment; port areas, pharmaceutical grade water mental monitoring programme is in adequate monitoring of controlled con- should be used wherever possible, and place within aseptic processing areas ditions (such as air flow and air pres- it should be microbiologically con- (cleanrooms). sure) along with alert settings that draw trolled and monitored. According to the US Food & Drug attention to a developing problem. Materials of animal, plant or natural Administration, environmental moni- There are many routes by which a mineral origin are considered to be of toring should promptly identify poten- cleanroom can become contaminated, higher risk than materials produced by tial routes of contamination, allowing personnel being one. In a well-designed chemical synthesis. However, any for implementation of corrections and controlled cleanroom, personnel materials introduced to an aseptic before product contamination occurs.1 Figure 2: Swabbing is are the most likely source of contami- processing area should be monitored It is one of the most important labora- used to monitor areas nation. This may originate in the for signs of damage and attention paid tory controls in aseptic processing, pro- that are difficult to changing room where personnel shed to the microbiological quality of the viding crucial information on the qual- access their own clothes and put on sterile material content. ity of the aseptic manufacturing envi- Disruption of airflow, air movement ronment; preventing the release of a and inadequate maintenance of HEPA potentially contaminated product; and filters could all cause contamination. preventing future contamination by HEPA filters should be free from leaks detecting adverse trends. around the sealing gaskets, frames and Ideally, a monitoring programme fabric. A high degree of air movement provides immediate feedback, allowing can pick up skin or dust particles from any problem to be rectified promptly. personnel or equipment, so cleanroom Environmental monitoring by micro- design should ensure that airflow biological means does not provide this sweeps particles away from the point- because of the incubation time required of-fill, product or other critical areas. to detect micro-organisms. Neverthe- Proper design will ensure uni-direc- less, the microbiological status of the tional airflow with no turbulence or cleanroom is a valuable tool that can stagnant air. indicate a loss of environmental control Although it is well known that the not picked up by other means. It also design and construction of the clean- serves as a reminder to personnel of the room should involve smooth surfaces importance of aseptic techniques. made of easy-to-clean materials, Environmental monitoring is only a special attention must be given to areas part of ensuring a sterile manufacturing that are difficult to clean and disinfect. environment. Other elements include: Different control measures should
www.manufacturing-chemist.info October 2006 manufacturing chemist 35 MC Oxoid p35_37 Sept 06 v3 12/15/06 9:33 AM Page 36