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 57: Analytical Method Validation (4)
- TR 60: Process Validation (4)
- TR 45: Depth Filtration (4)
- TR 70: Cleaning/Disinfection Programs (3)
- TR 14: Validation: Protein Purification Chromatography (3)
- TR 26: Sterilizing Filtration of Liquids (3)
- TR 88: Microbial Data Deviation Investigations in the Pharmaceutical Industry (3)
- TR 51: Biological Indicators (2)
- TR 56: Phase Appropriate cGMP Application (2)
- TR 67: Objectionable Microorganisms (2)
- TR 74: Reprocessing of Biopharmaceuticals (2)
- TR 15: Validation: TFF in Biopharmaceuticals (2)
- TR 76: Identification and Classification of Visible Nonconformities in Elastomeric Components and Aluminum Seals for Parenteral Packaging (2)
- TR 41: Virus Filtration (2)
- TR 42: Validation: Protein Manufacturing (2)
- TR 43: Glass Defects (2)
- TR 47: Virus Spikes/Virus Clearance (1)
- TR 48: Moist Heat Sterilizer Systems (1)
- TR 49: Validation: Cleaning Biotech (1)
- TR 53: Stability Testing New Drug Products (1)
- TR 54: QRM:Manufacturing Operations (1)
- TR 54-2: QRM: Packaging Labeling (1)
- TR 54-4: QRM: Biotech Drug Substance (1)
- TR 57-2: Analytical Method Development (1)
- TR 58: Temp Controlled Distribution (1)
- TR 3: Validation: Dry Heat (1)
- TR 38: Manufacturing Chromatography Systems Postapproval Changes (ChromPAC) (1)
- TR 29: Validation: Cleaning (1)
- TR 54-5: Quality Risk Management for the Design, Qualification, and Operation of Manufacturing Systems (1)
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Date of Manufacture
For small molecules, the date of manufacture of a drug product is considered to be the initial date that an active ingredient has been added during manufacturing. For biologics the date of manufacture can be determined in multiple ways and should be consistent with internal quality systems and the product license application. (TR53)
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Decision Maker(s)
Person(s) with the competence and authority to make appropriate and timely quality risk management decisions.(TR54) (TR54-2)
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Decommissioning
A planned and orderly removal of a facility, operation or system from use. (TR48)
The process of retiring equipment/systems/facilities from production use. (TR54-5)
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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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Dedicated Equipment
Equipment used exclusively for the manufacture of only one drug product, bulk drug substance, or intermediate. (TR29)
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Defect
(1) A departure of a quality characteristic from its intended level or state that occurs with a severity sufficient to cause an associated product or service not to satisfy its intended normal or foreseeable usage requirements. (TR51) (2) The nonfulfillment of intended usage requirements. The departure or absence of one or more quality characteristics from intended usage requirements. (TR43)
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Defect (ISO def.)
The nonfulfillment of intended usage requirements. The departure or absence of one or more quality characteristics from intended usage requirements. (TR76)
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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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Design of Experiments (DOE)
A method for carrying out carefully planned experiments on a process. Usually, DoE involves a series of experiments that initially involves evaluating many variables and then focuses on a few critical ones. (TR54-4)
A structured, organized method for determining the relationship between factors affecting an assay and output of that assay. (TR57) (TR57-2) (TR74)
A structured, organized method for determining the relationship between factors affecting a process and the output of that process (8). (TR60)
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Detergent
A synthetic wetting agent and emulsifier that can be added to a solvent to improve its cleaning efficiency. (TR70)
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Development Reports
Documentation and description of work done during the early phases of development. The goal is to document information about the way the process works and to document why key choices were made in selecting the specifics of the process (e.g., flow rate or temperature). These documents can serve as a reference during investigations of discrepancies and during the design of specific Validation and characterization studies.(TR14) (TR 42)
Documentation and description of work done during the early phases of development (Stage 1). The goal is to document information about the way the process works and to document why key choices were made in selecting the specifics of the process (e.g., flow rate or temperature). These documents can serve as a reference during investigations of deviations and during the design of specific validation and process characterization studies.(TR60)
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Deviation
Departure or digression from set parameters. (TR58)
Data or a result outside of the expected range or an unfulfilled requirement; it may be called nonconformity, defect, discrepancy, out-of-specification, out-of-limit, or adverse trend. (TR88)
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Diavolume (DV)
A volume equal to the retentate volume to which a diafiltration buffer is added. (TR15)
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Differential Pressure
The difference in pressure between the upstream (feed or influent) and downstream (effluent) sides of the filter. (May be modified with the terms: applied, available differential pressure, clean differential pressure, dirty differential pressure, initial differential pressure, or maximum differential pressure). [Synonym: Delta P (Δ P), PSID, Pressure Drop] (TR45) (TR26)
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Diffusion Flow Test
A test to determine the integrity of a filter. The test is based on the measurement of the diffusive (diffusional) flow of a gas through a wetted filter, along with any bulk flow of gas through open (unwetted) pores. Either the gas flow or the downstream liquid, displaced by the gas flow, may be measured. [Synonym: Forward Flow Test] (TR45)
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Diffusion Test (or Forward Flow Test)
A test for membrane integrity that involves measuring the rate of gas diffusion through a liquid-wetted membrane.(TR15) An integrity test in which a filter is subjected to differential gas pressures below the bubble point and gas molecule migration through the water-filled pores of a wetted membrane is measured. This behavior follows Fick’s Law of Diffusion (i.e., the gas diffusional flow rate for a filter is proportional to the differential pressure and the total surface area of the filter). (TR41)
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Diffusive/Forward Flow Test
A test to determine the integrity of a filter. [Synonym: diffusive flow test, forward flow test.] (TR26)
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Dimensional Product Quality
The product conforms to the required drawing dimensions. (TR43)(TR76)
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Direct Flow Filtration (DFF) or Normal Flow Filtration (NFF)
In direct flow filtration, all fluid is directed through the membrane in a single pass. (TR41)
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Downstream Side (of Filter)
The effluent side of the process step (filter). (TR45) The filtrate or outlet side of the filter. (TR26)
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Drug Development
A general term used to define the entire process of bringing a new drug to the Market. It includes drug discovery, process and product development, pre-clinical research (microorganisms/cell culture/animals) and Clinical trials (on humans). (TR56)
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Drug Product (DP)
A pharmaceutical product type that contains a drug substance, generally, in association with excipients. [Synonym: Dosage Form; Finished Product] (TR57)(TR14)(TR42)
A finished dosage form (e.g., tablet, capsule, or solution) that contains a drug substance, generally, but not necessarily, in association with one or more other ingredients.(TR38) (TR67) (TR88)
The dosage form in the final immediate packaging intended for marketing.(TR60)(TR82)
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Drug Substance (DS)
The active ingredient that is subsequently formulated with excipients to produce the drug product. It can be composed of the desired product, product-related substances, and product- and process-related impurities. It may also contain excipients, including buffers and other components. [Synonyms: bulk drug substance, bulk material, active pharmaceutical ingredient (API)] (TR14) (TR57) (TR74) (TR60)
Active pharmaceutical ingredient in a drug product that is responsible for that product’s therapeutic activity.(TR67) (TR82) (TR88)
See Active Pharmaceutical Ingredient (API). (TR56)
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Dynamic Light Scattering (DLS)
A technique used to measure the size and size distribution of particles. Particles suspended in a solution will cause scattering of light and the extent of the scattering is related to the size and shape of the particles. (TR47)