
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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- TR 70: Cleaning/Disinfection Programs (20)
- TR 1: Validation: Moist Heat (13)
- TR 3: Validation: Dry Heat (12)
- TR 61: Steam in Place (11)
- TR 62: Manual Aseptic Processes (11)
- TR 51: Biological Indicators (10)
- TR 22: Aseptic Process Simulation (10)
- TR 48: Moist Heat Sterilizer Systems (9)
- TR 45: Depth Filtration (9)
- TR 69: Bioburden/Biofilm Management (8)
- TR 13: Environmental Monitoring (8)
- TR 57: Analytical Method Validation (7)
- TR 47: Virus Spikes/Virus Clearance (6)
- TR 29: Validation: Cleaning (6)
- TR 50: Alt. Methods Mycoplasma Testing (4)
- TR 28: Process Simulation for Bulk API (4)
- TR 30: Parametric Release (4)
- TR 49: Validation: Cleaning Biotech (3)
- TR 15: Validation: TFF in Biopharmaceuticals (3)
- TR 77: The Manufacture of Sterile Pharmaceutical Products Using Blow-Fill-Seal Technology (3)
- TR 41: Virus Filtration (3)
- TR 44: QRM: Aseptic Processes (3)
- TR 55: TBA/TCA Detection Mitigation (2)
- TR 66: Single-Use Systems (2)
- TR 67: Objectionable Microorganisms (2)
- TR 14: Validation: Protein Purification Chromatography (2)
- TR 26: Sterilizing Filtration of Liquids (2)
- TR 83: Virus Contamination in Biomanufacturing: Risk Mitigation, Preparedness, and Response (2)
- TR 88: Microbial Data Deviation Investigations in the Pharmaceutical Industry (2)
- TR 78: Particulate Matter in Oral Dosage Forms (2)
- TR 76: Identification and Classification of Visible Nonconformities in Elastomeric Components and Aluminum Seals for Parenteral Packaging (2)
- TR 33: Rapid Micro Methods (2)
- TR 52: Supply Chain GDP (1)
- TR 54: QRM:Manufacturing Operations (1)
- TR 54-4: QRM: Biotech Drug Substance (1)
- TR 57-2: Analytical Method Development (1)
- TR 71: Emerging Methods for Virus Detection (1)
- TR 74: Reprocessing of Biopharmaceuticals (1)
- TR 84: Integrating Data Integrity Requirements into Manufacturing & Packaging Operations (1)
- TR 38: Manufacturing Chromatography Systems Postapproval Changes (ChromPAC) (1)
- TR 85: Enhanced Test Methods - Visible Particle Detection/Enumeration Closures/Containers (1)
- TR 43: Glass Defects (1)
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- Manufacturing (114)
- GMP/Good Manufacturing Processes/cGMP (93)
- Validation (92)
- Microbiology (86)
- Biotechnology (53)
- Virus (14)
- Combination Products (9)
- Filtration (9)
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- Vaccines (7)
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- Prefilled Syringes/PFS (4)
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Acceptance Limit
The maximum amount of residue allowed in a product, in an analytical sample, or as an amount per surface area. (TR29)
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Accuracy
The closeness of the actual test results obtained by the new method to the actual test results obtained by the existing method. (TR33) An analytical procedure expresses the closeness of agreement between the value that is accepted either as a conventional true value or an accepted reference value and the value found. This is sometimes termed trueness. (TR57)
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Adverse Event (AE) Report
An AE report is a communication to the U.S. FDA of an undesirable sign or symptom associated with use of a drug as required and detailed by 21 CFR 314.80. These reports are logged into the U.S. FDA’s Adverse Event Reporting System (AERS). Drug manufacturers are required to report adverse event information to FDA. These reports may also may be voluntarily submitted to the FDA directly by healthcare professionals or the general public at Med Watch. The reports are reviewed, safety issues are monitored, and data are periodically analyzed and assessed by the Center for Drug Evaluation and Research (CDER). (TR55)
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Adverse Trend
A series of alert-level or action-level excursions that indicates the system or areas are not in control and have the potential to affect the product quality. (TR 70)
An increase in the frequency of alert- and action-level excursions or repeated recovery of low levels of microorganisms below the alert level during microbial monitoring or of pharmaceutical ingredient or finished product failure that is indicative of a loss of process control. (TR88)
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Aggregation
Clumping of proteins, viruses, or bacteria that may arise from several mechanisms and may be classified in numerous ways, including soluble/insoluble, covalent/noncovalent, reversible/irreversible, and native/denatured. (TR47)
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Air Removal Test
A test used to evaluate air removal and steam penetration in an empty sterilizer that is used for porous/hard goods load sterilization (e.g., Bowie-Dick Test, DART, Lantor Cube, Browns’ Test). (TR01) (TR 48)
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Airlock
A room that controls the airflow between two rooms of different classification. (TR 70)
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Amplicon
A segment of double stranded DNA formed as the product of polymerase chain reaction or other amplification based techniques such as TMA or NASBA. (TR50)
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Anaerobe
An organism that has the ability to grow in the absence of oxygen. (TR51)
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Aseptic Processing Simulation (APS)
A means for establishing the capability of an aseptic process as performed using a growth medium. (TR22) (TR62)
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Bias
A systematic difference in a method that manifests itself as a deviation of the method mean from an expected value. (TR57) Total systematic error, in contrast to random error. Measurement centered on the true result is said to be unbiased or have no systematic error. The distance between the center of a large (infinite) number of measurements and the correct value is the bias. (TR 57-2)
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Bioanalytical Test Method
A method used to assess the presence of analytes (chemical or biological) in biological samples (e.g., serum, plasma, etc.). (TR57)
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Bioassay
Analysis (as of a drug) to quantify the biological activity(ies) of one or more components by determining its capacity for producing an expected biological activity. (TR57)
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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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Biofouling (or Biological Fouling)
Accumulation and subsequent deleterious effects of biological contaminants on engineered products or processes (TR 69)
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Biological Activity
Property that describes the specific ability or capacity of a product to achieve a defined biological effect. (TR57)
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Biological Indicator (BI)
An inoculated carrier contained within its primary pack ready for use and providing a defined resistance to the specified sterilization process. (TR51)
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Biological Qualification
A component of performance qualification that demonstrates, by use of biological indicators, that the required lethality (FBIO) is achieved consistently throughout the load. (TR1) (TR3) (TR30) A component of performance qualification that demonstrates, by use of biological indicators, that the required lethality (FBIO) or spore log reduction (SLR) is achieved consistently throughout the sterilized or sanitized portion of the SIP system. (TR61)
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Biological Safety Cabinet (BSC)
An enclosed, ventilated workspace with engineering controls designed to remove or minimize exposure to hazardous biological materials. A BSC is a principle device to provide containment of infectious splashes or aerosols generated by many microbiological procedures. BSCs are designed to provide personnel, environmental and product protection when appropriate practices and procedures are followed. A cabinet that is designed to protect the operator and the environment from the hazards of handling infected material and other dangerous biological. (TR62)
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Biological Tests
Biological tests include animal, cell culture, or biochemical based testing that measures a biological, biochemical, or physiological response. (TR38)
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Biomethylation
The enzyme chlorophenol o-methyltransferase responsible for fungal methylation has been isolated in cell-free extracts. Biomethylation, in this context, may be seen as a detoxification mechanism, although it plays a role in the production of mycotoxins by secondary metabolism. Slightly xerophilic fungi frequently associated halophenol biomethylation include Trichoderma longibrachiatum, Trichoderma virgatum, Aspergillus sydowii, and Penicillium islandicum. (TR55)
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Contact Time
The minimum amount of time that a sanitizer, disinfectant, or sporicide must be left in complete (wet) contact with the surface to be treated in order to be effective. (TR70)
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Container Closure Integrity (CCI)
The ability of a package to prevent product loss, to block microorganism ingress, and to limit entry of detrimental gases or other substances, thus ensuring that the product meets all necessary safety and quality standards.(TR76)
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Container Cold Spot
The location within a sealed liquid container that achieves the lowest process lethality (F0) during a sterilization process. (TR01)
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Contaminant
Any adventitiously or externally introduced material(s) (e.g., chemical, biochemical, or microbial species) not intended to be part of the process. (TR14) (TR15) (TR70)
An undesired impurity of a chemical or microbiological nature that is introduced into a raw material, intermediate, or API (drug substance) during manufacture. (TR14) (TR15)
Any adventitiously introduced materials (e.g., chemical, biochemical, or microbial species) not intended to be part of the manufacturing process of the drug substance or drug product. (TR69) (TR74)
Any adventitiously introduced material (e.g., chemical, biochemical) or microorganisms including viruses not intended to be included in the manufacturing process of the drug substance or drug product. (TR83)
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Contamination Rate
The percentage of units filled in a process simulation that are positive for microbial growth after incubation. (TR22)
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Cool-Down Phase
The phase of a sterilization cycle that occurs after completion of the exposure phase. Parameters of a cool-down phase are typically defined in order to meet applicable user requirements for load cooling and drying. (TR01) The phase of a sterilization cycle that occurs after completion of the exposure phase. [Synonym: post-conditioning phase, slow exhaust phase, drying phase, equalization phase] (TR48) The phase of an SIP cycle that occurs after completion of the exposure phase. Parameters (e.g., time, temperature, pressure) of a cool-down phase are typically defined in order to meet applicable user requirements for system cooling and drying. (TR61)
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Coupon
A small, generally flat portion of a defined material of construction (such as stainless steel or PTFE) and of a defined surface finish, typically used for laboratory cleaning evaluations and/or for laboratory sampling recovery studies. (TR29) (TR49)
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Coverage
The appropriate distribution of a chemical agent needed on the equipment surface to be effective. (TR70)
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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 Process (CP)
A process that impacts a critical quality attribute of the intermediate, drug substance or drug product being manufactured and therefore should have established critical process parameters that can be monitored or controlled to ensure that the process produces the desired quality.
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Cycle Development
A series of activities performed for the purpose of defining or confirming the cycle parameters (e.g., time, temperature, pressure) necessary to ensure sanitization or sterilization. (TR61)
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Cycle Phases
A discrete series of sterilizer process steps (such as, heat-up, exposure and cool-down) performed sequentially that represent a complete sterilization cycle. (TR48)
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Cytopathic Effect (CPe)
Morphological changes induced by viruses in infected cells in invitro culture. They are usually localized around a site of initial infection and vary in appearance based on the virus and the cultured cell. (TR47)
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Cytopathic Virus
Viruses where infection of cells results in microscopically visible degeneration of the cells or other morphological changes. (TR47)
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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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D-value (D10 -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. (TR51)
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DT Value
The time in minutes required for a onelogarithm, or 90%, reduction of the population of microorganisms used as a biological indicator under specified lethal conditions. For steam sterilization, the D-value should always be specified with a reference temperature, DT . For example, a BI system with a D121°C = 1.4 minutes requires 1.4 minutes at 121°C to reduce the population by one logarithm.(TR1) (TR61)
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Dead Leg
Area of entrapment in a vessel or piping run that could lead to contamination of the product. (TR69)
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Deadlegs
An area of entrapment in the vessel or piping run that could lead to contamination of the product due to insufficient exposure to moist heat. (TR61)
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Decontamination
A process that is designed to remove soil (including microorganisms) and may consist of cleaning and/or disinfection. (TR51)
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Degradation
The breakdown (usually chemical) of material during manufacture, including during and after the cleaning process. (TR49) (TR70)
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Degradation Product
Molecular variants resulting from changes in the desired product or product-related substance brought about over time and/or by the action of light, temperature, pH, water, etc., or by reaction with an excipient and/or the immediate container/ closure system. Such changes may occur because of manufacture and/or storage (e.g., deamidation, oxidation, aggregation, proteolysis). Degradation products may be either product-related substance or product-related impurities. (TR57)
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Deionized Water
Water treated by passing through both cation- and anion-exchange resin beds, or a mixed-resin bed to remove both positive and negative ions. (TR45)
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Depyrogenation
The destruction and/or removal of bacterial endotoxins. A depyrogenation process should demonstrate at least 99.9% or a 3-log endotoxin reduction. (TR3) Removal or destruction of pyrogens. (TR70)
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Dirty Hold Time
The time from the end of product manufacturing until the beginning of the cleaning process (also called “soiled hold time”). (TR29)
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Disinfectant
A chemical or physical agent that reduces, destroys, or eliminates vegetative forms of harmful microorganisms but not spores. (TR70)
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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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Dryness Fraction
An absolute measure of the actual latent heat of a sample of steam relative to the theoretical latent heat of saturated steam. (TR01) (TR48)
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Dryness Value
A dimensionless test quantity developed to approximate the dryness fraction. (TR01)