PDA Technical Glossary

PDA Technical Reports are highly valued membership benefits because they offer expert guidance and opinions on important scientific and regulatory topics and are used as essential references by industry and regulatory authorities around the world. These reports include terms which explain the material and enhance the reader’s understanding.

The database presented here includes the glossary terms from all current technical reports. The database is searchable by keyword, topic, or by technical report. Each definition provided includes a link to the source technical report within the  PDA Technical Report Portal.

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Spore
A bacterial dormant form that is highly resistant to adverse conditions. Fungal spores are not highly resistant; their susceptibilities are closer to vegetative microorganisms. (TR13)

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Static Monitoring
Monitoring of the environment in the absence of normal operations. This includes having the equipment installed and operational when no personnel are present. Per the EU and ISO standards, this is synonymous with “at rest.” (TR13)

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Strain
A specific isolate of a species that is maintained in pure culture and is serotypically, genotypically, or chemotaxonomically characterized to differentiate it from other strains of the same species. The strain is representative of the species and provides a reference for the species based on its historic isolation, characterization, and deposition in recognized culture collections. (TR13)

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Restricted Access Barrier System (RABS)
RABS are aseptic processing systems (ISO 5) intended to substantially reduce human borne contamination within the aseptic environment where sterile product, containers, closures and equipment are exposed by the use of separative devices and defined mechanical features and operating procedures. (TR22) (TR62) Aseptic processing systems (ISO 5) intended to substantially reduce human-borne contamination within the aseptic environment where sterile product, containers, closures, and equipment are exposed by the use of separative devices and defined mechanical features and operating procedures. (TR13)

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Sanitization
Reduction of microbial contaminants to safe levels as judged by public health requirements for the specific country. (TR13) A significant reduction in bioburden, achieved in chromatography by the use of bactericidal agents, such as sodium hydroxide (NaOH), hydrochloric acid (HCl), ethanol (EtOH), and isopropanol (IPA). (TR14) The process of reducing microbial levels by treatment at less than defined sterilizing conditions. Typically water at 80 °C or a chemical treatment is used to perform sanitization of process components. (TR45) A process that reduces the number of viable microorganisms to a defined level. (TR61) (TR69)

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Parametric Release
A sterility release system based upon effective control, monitoring, documentation, and batch records review of a validated sterilization process cycle in lieu of release procedures based upon end-product sterility testing. (TR01) (TR3) (TR13) A sterility release program based on effective control, monitoring and documentation of a validated sterile-product manufacturing process where sterility release is based on demonstrated achievement of critical operational parameters and performance attributes in lieu of end-product sterility testing. (TR30)

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Microbial Classification
The arrangement of microorganisms into taxonomic groups based on their similarities and relationships. (TR13)

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Microbial Identification
The determination of the genus, and species when possible, to which a laboratory or manufacturing isolate belongs. (TR13)

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Nonviable
A term used in reference to particulates that are not capable of living, growing, or developing and functioning successfully (“unable to divide” or “not capable of reproducing”). (TR13)

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Isolator, Open
A decontaminated unit meeting ISO 5 conditions that provides uncompromised, continuous, isolation of its interior from the surrounding environment. It may transfer air directly to the surrounding environment through openings (e.g., “mouse holes”) that preclude the ingress of microbial contamination. (TR13) (TR22) (TR62)

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Frequent Monitoring
A process of collecting data in which conditions are monitored at a defined frequency not exceeding sixty minutes during operation. In most U.S. applications, this means “during production.” (TR13)

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Grid Profiling
A process of dividing areas of equivalent classifications into grids for the purpose of uniformly assessing contamination characteristics in that area.This process is usually confined to the validation of new facilities and not routine monitoring. (TR13)

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D-Value
The time in minutes required for a one-logarithm, or 90%, reduction of the population of microorganisms used as a biological indicator under specified lethal conditions. For dry-heat sterilization, the D-value should always be specified with a reference temperature, DT. For example, a biological indicator (BI) challenge system with a D 160°C=1.9 minutes, requires 1.9 minutes at 160°C to reduce the population by one logarithm. (TR3) The time in minutes at a specific temperature required to reduce the population of a specific microorganism by 90% [or one (1) log] in defined conditions [e.g., method of sterilization (dry heat versus steam), solute, or carrier]. (TR13)

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Disinfection
The destruction of pathogenic and other kinds of microorganisms by thermal or chemical means. (TR51) (TR70) Process of eliminating nearly all recognized pathogenic microorganisms but not necessarily all microbial forms (e.g., bacterial spores) on inanimate objects. (TR69) The chemical or physical inactivation of a bioburden on inanimate surfaces. Typically this requires a minimum three-log (3-log) reduction of vegetative microorganisms and two-log (2-log) reduction for bacterial spore be achieved in validation. (TR13)

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Environmental Control Parameters
Conditions and corresponding measurements as associated with facilities and equipment used in the control of a manufacturing area that may impact the identity, strength, quality, or purity of a product. Among such parameters are airflow rates and patterns, pressure differentials, materials and personnel flow, temperature and relative humidity, as well as nonviable and viable particulates. (TR13)

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Critical Area/Critical Zone
An area designed to maintain sterility of sterile materials. Sterilized product, containers, closures, and equipment may be exposed in critical areas. (TR13) (TR22) (TR44) (TR62)

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Critical Surface
A surface within a critical area that may come in direct contact with sterilized products, containers, or closures. (TR13)

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Cleanroom
A room designed, maintained, and controlled to prevent particle and microbiological contamination of a drug product or medical device. A cleanroom is assigned and reproducibly meets an appropriate air cleanliness classification. (TR13)

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Bioburden
The total number of microorganisms per unit of material prior to sterilization. (TR13) Total number of viable microorganisms on or in a health care product prior to sterilization. (TR22)(TR61)(TR62) A population of viable microorganisms in a fluid prior to sterilizing filtration. (TR26) A measure of the contaminating organisms found in or on a given amount of material before it undergoes a sterilization process. (TR45) (TR70) The number of detectable microorganisms (bacteria and fungi) with which an object is contaminated. It is measured in CFU (colony forming units). (TR47) The number of viable, contaminating microorganisms present on a product immediately prior to decontamination. (TR51) Viable microbial contaminants associated with personnel manufacturing environments (air and surfaces), equipment, product packaging, raw materials (including water), in-process materials, and finished products. (TR 67) (TR 69)

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Airborne Particulate Count (Total Particulate Count)
The total number of particles of a specific size per unit volume of air. (TR13)

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Airborne Viable Particulate Count (Total Airborne Aerobic Microbial Count)
The total number of particles of a specific size per unit volume of air. (TR13)

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Aseptic Processing
Handling sterile materials in a controlled environment, in which the air supply, facility, materials, equipment and personnel are regulated to control microbial and particulate contamination to acceptable levels. (TR28) (TR62) (TR69) Handling of sterile product, containers, and/ or devices in a controlled environment in which the air supply, materials, equipment, and personnel are regulated to maintain (product) sterility. (TR13)

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Alert Level
An established microbial or nonviable particle level giving early warning of potential drift from normal operating conditions; not necessarily grounds for definitive corrective action but typically requires follow-up investigation. (TR13) (TR22) (TR69) An established level that, when exceeded, is giving an early warning of a potential drift from normal operating conditions; while not necessarily grounds for definitive corrective action, it typically requires follow-up review. (TR 60) An established microbial or nonviable particle level giving early warning of potential drift from normal operating conditions; not necessarily grounds for definitive corrective action, but typically requires follow-up investigation (3, 4, 7). (TR88)

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Action Level
An established microbial or airborne particle level that, when exceeded, indicates a process is outside of its normal operating range. A response to such an excursion should involve a documented investigation and corrective actions based on the results of that investigation. (TR13) An established microbial or non-viable particle level that, when exceeded, should trigger appropriate investigation and corrective action based on the investigation. (TR22) An established microbial or airborne particle level for environmental, water or gas monitoring that, when exceeded, indicates that a facility process is outside of its normal operating range. The response to such an excursion involves a documented investigation and corrective actions based on the results of that investigation. The prescribed action level is often specified in guidance or standards relating to environmental monitoring and water quality. (TR69) An established microbial or nonviable particle level for environmental, water, or gas monitoring that, when exceeded, indicates a facility or process is outside of its normal operating range. The response to such an excursion may involve a documented investigation and corrective actions based on the results. The prescribed action level is often specified in guidances or standards relating to environmental monitoring and water quality (3-6). (TR88)

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