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PDA Glossary

PDA Glossary of Pharmaceutical and Biotechnology Terminology

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.

Browse Terms by Title


Browse Terms by TR #

  • Adsorption

    Retention of solutes, suspended colloidal particles or microorganisms to fluid contact surfaces, e.g., the surfaces of pores in the filter medium. (May be modified with the following terms: electrokinetic, charge-rated, surface charge, hydrophobic or ionic strength. (TR45)

    The retention of solutes, suspended colloidal particles or microorganisms to fluid contact surfaces, e.g., the surfaces of pores in filtration membranes. (TR26)

  • Adverse Drug Reaction (ADR)

    The American Society of Hospital Pharmacists (ASHP) defines a significant ADR as any unexpected, unintended, undesired, or excessive response to a drug that:
    (1) Requires discontinuing the drug (therapeutic or diagnostic) Requires changing the drug therapy
    (2) Requires modifying the dose (except for minor dosage adjustment)
    (3) Necessitates admission to a hospital
    (4) Prolongs stay in a healthcare facility
    (5) Necessitates supportive treatment
    (6) Significantly complicates diagnosis
    (7) Negatively affects prognosis
    (8) Results in temporary or permanent harm, disability, or death.
    The World Health Organization (WHO) defines ADR as any noxious, unintended, and undesired effect of a drug which occurs at doses used for prophylaxis, diagnosis, or therapy, excluding therapeutic failures, intentional and accidental overdose and drug abuse. It does not consider errors in drug administration to be adverse events. (TR55)

  • 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)

  • 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)

  • 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)

  • Audit Trail Review Assessment (ATRA)

    A tool that can be used to help determine what elements within the audit trail should be reviewed, and the frequency at which the review should take place for each part of the audit trail where a review is required.

  • Automated Inspection

    Consists of mechanical handling and presenta­tion of product containers combined with auto­mated inspection of the filled containers using image analysis and/or light obscuration. (TR79)

  • 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)

  • Calibration Curve

    The relationship between measured response values and analytical concentrations of a standard or reference material. (TR57)

  • Calibration Tolerance

    In metrology, the maximum permissible range around a specified value that applies to a properly functioning measuring instrument. [Synonym calibration uncertainty, error](TR48)

  • Campaign

    A series of consecutive production batches manufactured without intervening cleaning and sterilization. (TR13) (TR22) (TR62)

    Processing of multiple lots or batches of the same product serially in the same equipment. (TR29) (TR49)

  • Campaigning

    Extending the period of time, or number of cycles a single-use system is operating in a closed process without breaking the sterile barrier processes. The end user is responsible to evaluate and determine if appropriate quality requirements are met for their application. (TR 66)

  • Capsule

    A self-contained filter device. (TR45)

  • Capsule Filter

    Compact, self-contained filter assembly. Generally, the whole assembly is disposable. (TR26) (TR41)

  • Captive Pallets

    A pallet intended for use within the confines of a single facility or system not intended to be exchanged. These are frequently metal or plastic pallets in Good Manufacturing Practices (GMP) manufacturing areas. (TR55)

  • Carrier

    A solid support upon which the test organism used in biological monitoring is inoculated. (TR51)

  • Cartridge

    A filter device requiring a housing for use. (TR45)

  • Cartridge Filter

    Filter elements encased in a housing. Generally, the filter elements are disposable while the housing units are multi-use. In a few cases, both filter and housings are disposable. (TR26) (TR41)

  • Cassette

    A tangential flow filtration module containing flat sheet, semipermeable membranes, feed channel and filtrate flow channels. (TR15)

  • Certificate of Analysis (CoA)

    The certification by a supplier of the performance of the material tested against a set of specifications, such asidentity, purity, moisture content, pH, color, bioburden, endotoxin, etc. (TR56)

  • Class I Recall

    A situation in which there is a reasonable probability that the use of or exposure to a violative product will cause serious adverse health consequences or death. (TR55)

  • Class II Recall

    A situation in which use of or exposure to a violative product or may cause temporary or medically reversible adverse health consequences or where the probability of serious adverse health consequence is remote.(TR55)

  • Class III Recall

    A situation in which use of or exposure to a violative product is not likely to cause adverse health consequences.(TR55)

  • Clean

    Having product residues, process residues, and environmental contaminants removed to an acceptable level. (TR29) (TR49)

    The implementation of procedures to render an area, piece of equipment, system, or object free of adulterants and contaminants. (TR 70)

  • Clean Hold Time

    The time from the end of the cleaning process until the equipment is used again (which may be product manufacture, autoclaving, or a steam in place (SIP) cycle). (TR29)

  • Clean in Place (CIP)

    The process of rinsing or washing of process components, as installed without removal, in order to remove or eliminate any contaminants. (TR45)

  • Clean Water Flux

    A baseline filter flow measurement performed with clean water or a buffer, at a specified transmembrane pressure and temperature. (TR15)

  • Clean(liness)

    The measurement for the level of particulates, microbes, or other extraneous substances on an item or surface. (TR 70)

  • Cleaning

    The process of removing foulants from the membrane structure during normal processing, either through physical or chemical means. (TR13) (TR15)

    The removal of adherent visible soil from the surfaces, crevices, serrations, joints, and lumens of instruments, and from devices and equipment, by a manual or mechanical process that prepares the items for safe handling and/or further decontamination. The cleaning process should leave surfaces that are visibly free from foreign material. (TR51)

  • Cleaning Agent

    The solution or solvent used in the washing step of a cleaning process. Examples of cleaning agents are water, organic solvent, commodity chemical diluted in water, and formulated detergent diluted in water. (TR29) (TR70)

  • Cleaning Procedure

    The documentation that assures any product and process-related material introduced into equipment as part of the manufacturing process stream is removed and the equipment is adequately stored. (TR29)

  • Cleaning Process

    A process that is used to remove any product, process-related material and environmental contaminant introduced into equipment as part of the manufacturing stream. (TR29)(TR49)

  • Cleaning Validation

    Documented evidence with a high degree of assurance that a cleaning process will result in products meeting their predetermined quality attributes throughout its life cycle. (TR29)(TR49)

  • Cleaning Verification

    A one-time sampling and testing to ensure that specified equipment has been properly cleaned following a specific cleaning event. (TR29) (TR49)

  • Clinician

    A physician, psychiatrist, etc., who specializes in clinical work as opposed to one engaged in laboratory or experimental studies. (TR58)

  • Cloning

    The process of creating identical copies of DNA fragments or a homogeneous preparation of cells, viruses or other organisms. (TR47)

  • Commissioning

    A well planned, documented and managed engineering approach to the start-up and transfer of facilities, systems and equipment to the end-user that results in a safe and functional environment that meets established design and user requirement specifications. Commissioning precedes Qualification and includes three phases:
    1. Inspection, testing, and regulation
    2. Adjustment and setting of work
    3. Functional testing (TR 3)

    A prescribed number of activities designed to take equipment and systems from a static, substantially complete state to an operable state. (TR 48)

    A well planned, documented, managed engineering approach to the start-up and turnover of facilities, systems, and equipment to the end-user, that results in a safe and functional environment that meets established design requirements and stakeholder expectations.(TR 54) (TR 54-5)

  • Comparability Protocol

    A protocol submitted by an applicant under CFR 601.12(e) and 314.70 (g) that describes the specific tests and validation studies and acceptable limits to be achieved to demonstrate the lack of adverse effect for specified types of manufacturing changes on the identity, strength, quality, purity, and potency of the product as they may relate to the safety or effectiveness of the product. Any such protocols, or change to a protocol, shall be submitted as a supplement requiring approval from FDA prior to distribution of the product. The supplement, if approved, may justify a reduced reporting category for the particular change because the use of the protocol for that type of change reduces the potential risk of an adverse effect. (TR38)

  • Comparability Study

    An assessment of the similarities between the critical parameters and output results of two or more separate processes or methods. (TR50)

  • Comparative Transfer

    Transfer of a method that involves the analysis of a predetermined number of samples of the same lot by both the sending and the receiving unit. (TR 57-2)

  • Compatibility

    Proof that no adverse interaction between the filter and the process fluid has occurred. (TR26)

    A term used in relation to the non-reactivity of filter materials with the substance to be filtered. (TR45)

  • Compatibility (Filter)

    The ability of a filter to be used with a particular process fluid without a change in the inherent properties of the filter. (TR41)

  • Compendial Procedure

    A method that is considered validated as published in one of the recognized compendia. (TR57)

  • Complaint Files

    (a) As defined by 21 CFR Part 211.198- Complaint Files. (b) A written record of each complaint shall be maintained in a file designated for drug product complaints. The file regarding such drug product complaints shall be maintained at the establishment where the drug product involved was manufactured, processed, or packed, or such file may be maintained at another facility if the written records in such files are readily available for inspection at that other facility.
    1.The written record shall include the following information, where known: the name and strength of the drug product, lot number, name of complainant, nature of complaint, and reply to complainant .
    2.Where an investigation under 211.192 is conducted, the written record shall include the findings of the investigation and follow-up. The record or copy of the record of the investigation shall be maintained at the establishment where the investigation occurred in accordance with 211.180. (TR55)

  • Corrective Action

    Actions taken to eliminate the cause of an existing (corrective) or potential (preventative) non-conformity to prevent its recurrence. (TR52)

    Action to eliminate the cause of a detected non-conformity or other undesirable situation. (TR54)

    A response taken to remediate the effect of an excursion or product failure. (TR13)

  • Corrective Action and Preventative Action (CAPA)

    Action to eliminate the cause of a detected nonconformity or other undesirable situation. NOTE: Corrective action is taken to prevent recurrence, whereas preventive action is taken to prevent occurrence. (TR 52) (TR 54-2) (TR 54-3) (TR 54-5)

  • Decision Maker(s)

    Person(s) with the competence and authority to make appropriate and timely quality risk management decisions.(TR54) (TR54-2)

  • Documentation

    See Development Reports , Process Characterization Report , Process Validation Protocol, or Process Validation Report (TR14) (TR42)

  • Emulsions

    A dispersed colloidal system consisting of two immiscible liquid phases generally stabilized with one or more suitable agents. Injectable emulsions are sterile liquid dosage forms of drug substances dissolved or dispersed in a suitable emulsion me­dium. Injectable emulsions are for parenteral ad­ministration of poorly water-soluble drugs. (TR79)

  • Extemporaneous Preparation (EP)

    A type of compounding whereby a drug or combination of drugs and/or excipients is prepared under the supervision of a pharmacist to create a customized medication dosage form in accordance with a clinical protocol. (TR63)

  • Factory Acceptance Test (FAT)

    A test typically conducted by the sterilizer manufacturer after the system has been assembled and before the system is shipped to the installation site. (TR48) (TR54-5)

  • Fault Tree Analysis (FTA)

    A deductive technique used to analyze the causes of faults (defects). The technique visually models how logical relationships between failures, human errors, and external events can combine to cause specific faults. (TR54) (TR54-2) (TR54-3) (TR54-5)

  • FDA Form 483

    Inspectional observation sheet used by FDA investigators to document their findings. (TR67)

  • Gels

    Gels (sometimes called jellies) are semisolid sys­tems consisting either of suspensions of small inorganic particles or of organic molecules inter­penetrated by a liquid. Gels can be classed either as single-phase or two-phase systems. (TR79)

  • Historical Data

    For purposes of this guidance, data on impurities or physical attributes from three or more consecutive, representative pre-modification batches. (TR38)

  • Implants

    Implants are long-acting dosage forms that provide continuous release of an API for periods of months to years. They are administered by the parenteral route. For systemic delivery, they may be placed subcutaneously or, for local delivery, they can be placed in a specific region in the body. (TR79)

  • Incident

    Any event that occurs during the shelf life of a product that may have an adverse effect on quality (e.g., temperature excursion, missing temperature monitor when required, shipment time in excess of qualified packout duration, wet/ crushed packaging). (TR58)

  • Incident Management System

    Part of the Quality Management System that handles incidents, deviations, excursions, and exceptions in the supply chain. (TR58)

  • Incoming Inspection

    A preventative program where parts or products are subjected to evaluation upon receipt.(TR43)

    A program where, upon receipt, parts or products are subjected to measuring, examining, testing, or gauging one or more characteristics of a product or service, and comparing the results with specified requirements in order to establish whether conformity is achieved for each characteristic.(TR 76)

  • ISO 5

    Environmental operating conditions defined in ISO 14644-1, “Cleanrooms and associated controlled environments”. (Note: For total particulates, ISO 5 approximates the Class 100 description from the now obsolete U.S. Federal Standard 2009 and is roughly comparable to Grade A as defined in European GMP Annex 1 – “Manufacture of Sterile Medicinal Products.”) (TR22) (TR62)

  • ISO 7

    Environmental operating conditions defined in ISO 14644-1, “Cleanrooms and associated controlled environments.” Note: For total particulates, ISO 7 approximates Class 10,000 from the now obsolete Federal Standard 209. (TR62)

  • ISO 8

    Environmental operating conditions defined in ISO 14644-1, “Cleanrooms and associated controlled environments.” Note: For total particulates, ISO 8 approximates Class 100,000 from the now obsolete Federal Standard 209. (TR62)


    International Organization for Standardization/International Electrotechnical Commision. (TR52)

  • Justification

    Reports containing scientific data and expert professional judgment to substantiate decisions. (TR38)

  • Lost Work Day (LWD)

    A day on which an employee does not work because of injury in a work-related accident. (TR52)

  • Lot or Batch

    A specific quantity of material produced in a process or series of processes so that it is expected to be homogeneous within specified limits.(TR76)

  • Lyophilized (Product Cake)

    Freeze-dried product typically in the form of a solid plug or cake in the container. (TR79)

  • Manual Baseline

    Data generated from visual inspection of a blind­ed set of seeded test containers that demonstrates the detection capability of human inspection. The test set is sometimes referred to as a “particle size threshold set,” where various foreign particu­late types in a gradation of sizes are examined to yield a statistically significant probability of de­tection percentage for each unit. This allows the determination of what types and sizes of particu­lates can be reproducibly detected in a specific product/container system. (TR79)

  • Manual Inspection

    Consists of manual handling and presentation of filled containers under controlled conditions of lighting and background to allow for human visual inspection. (TR79)

  • Material Safety Data Sheet (MSDS)

    Information provided with chemicals and other materials intended to provide workers and emergency personnel with procedures for handling or working with that substance in a safe manner. Includes information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill-handling procedures. (TR65)

  • Method Comparability

    The demonstration of analytical method comparability (AMC) for method replacements. A study to demonstrate that a modification to an existing method either improves or does not significantly change the analytical procedure’s characteristics relative to the methods’ validation and intended use. (TR57)

  • Powders

    Powders are defined as a solid or a mixture of sol­ids in a finely divided state intended for internal or external use. Powders used as pharmaceutical dosage forms may contain one or more APIs and can be mixed with water for oral administration or injection. (TR79)

  • Probability of Detection

    The likelihood of detecting a defective unit dur­ing an inspection process expressed as a prob­ability, quantitatively as a number (0–1) or as a percentage (0–100%). (TR79)

  • Qualification or Validation Set

    A set is used for the qualification of manual, semiautomated, and validation of automated inspection to determine the acceptability of per­formance. (TR79)

  • Reportable result

    The final analytical result. This result is defined in the written approved test method and derived from one full execution of that method, starting from the original sample. (TR57)

  • Requirements Traceability Matrix (RTM)

    The RTM traces requirements to IQ/OQ and/or PQ (also known as User Acceptance Test), con­figuration, design, procedures, policies, and/or user manuals. (TR54-5)

  • Reserve/Reference Samples

    An appropriately identified reserve sample that is representative of each lot of intermediate product and in each shipment of each active ingredient shall be retained (at least twice the quantity nec­essary for all tests required to determine whether the active ingredient meets its established specifi­cations; this is a regulatory Requirement). (TR56)

  • Semiautomated Inspection

    Consists of machine-assisted handling and pre­sentation of filled containers to allow for human visual inspection. (TR79)

  • Significant Body of Information

    A significant body of information on the stability of the drug product is likely to exist after 5 years of commercial experience for new molecular entities, or 3 years of commercial experience for new dosage forms (TR38)

  • Subject Matter Experts (SMEs)

    Individuals with specific technical expertise such as engineers, quality experts, automation special­ists, scientists, etc. (TR54-5)

  • Supplemental Testing or Inspection

    Destructive reconstitution, dilution, transfer, clearing, solubilizing, filtration, screening, or sieving that allows a product to be visually exam­ined or evaluated microscopically to determine the presence, type, and size of foreign particulate contamination present within the product, con­tainer, or device. (TR79)

  • Suspensions

    A suspension is a biphasic preparation consisting of solid particles dispersed throughout a liquid phase. Some suspensions are prepared and ready for use, and others are prepared as solid mixtures intended for reconstitution with an appropriate vehicle just before use. (TR79)

  • Tyndall Lighting

    Collimated lighting at right angle to the viewing direction, typically against a black or dark back­ground, which is useful during manual visual inspection to detect fine dispersions of small par­ticulate that scatter the light making them more detectable. (TR79)

  • Verified Clean

    The verified clean testing materials undergo a cleaning or washing process to remove particu­lates with an evaluation for acceptance (e.g., blank) to assure the system’s suitability for use in testing or inspection. (TR79)

  • Warning Letters

    Type of correspondence that notifies a regulated industry about violations that FDA has documented during its inspections or investigations. (TR67)