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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 #

  • Validation

    A documented program that provides a high level of scientific assurance that a manufacturing process will reliably produce acceptable product. The proof of validation is obtained through rational experimental design and the evaluation of data, preferably beginning from the process development phase and continuing through the commercial production phase. (TR01)

    A documented program that provides a high degree of assurance that a specific process, method, or system will consistently produce a result meeting predetermined acceptance criteria. (TR26) (TR57) (TR70) (TR74)

    Documented testing, performed under highly controlled conditions, which demonstrates that a process consistently produces a result that meets predetermined acceptance a result that meets predetermined acceptance criteria. Used to test processes, methods, and systems for which conditions can be controlled in the real world (i.e., after completion of testing, when the process is in use). Transportation processes can be qualified but not validated; in the real world, it is not possible to exert control over all parameters that could affect the transportation process (e.g., weather, customs, traffic delays, mechanical failures, etc.). (TR58)

    A documented program that provides a high de­gree of assurance that a specific process, method, or system will consistently produce a result meeting predetermined acceptance criteria. (Note: Vali­dation is a lifecycle program which may include development and qualification activities for one or more elements/systems that form a process.) (TR54-5)

    A documented program that provides a high degree of assurance that a specific process, method, or system will consistently produce a result meeting pre-determined acceptance criteria (17). (TR60-3)

  • Validation Reference Standards

    Reference standard preparations used for method validations. (TR50)

  • Validation, partial

    A documented prospective study intended to demonstrate suitability for the intended use of previously validated methods, specifically for new products and/or processes. (TR57)

  • Value Stream Map

    A tool used to document, analyze, understand and improve the flow of information or materials required to produce a product or service for a customer as it makes its way through the value stream. (TR68)

  • Value-added Activities

    Includes the management of materials, operations, qualification, verification, vender audits, materials testing, and shop-floor oversight that allows an SUS to be used in operations. (TR66)

  • Vapor

    The gaseous form of materials that are normally liquids or solids at room temperature and pressure. (TR51)

  • Vapor Phase Hydrogen Peroxide (VPHP)

    A disinfection system in which 35% hydrogen peroxide is changed to a vapor phase and used for bioburden reduction of a chamber or items in a chamber. (TR70)

  • Vegetative Cell

    Cells in an actively growing state. Some microorganisms can only be vegetative, while others are sporeformers and can be in a vegetative or spore (dormant) state. (TR13)

  • Velocity

    The average linear rate of fluid flow equal to the volumetric flow rate divided by the cross-sectional area of the flow channel. (TR15)

  • Verification

    A systematic approach to verify that manufacturing systems, acting singly or in combination, are fit for intended use, have been properly installed, and are operating correctly. This is an umbrella term that encompasses all types of approaches to assuring equipment is fit for use. Approaches include qualification, commissioning and qualification, verification, system validation, or other. (TR3) (TR60)

    A systematic approach to verify that manufactur­ing systems, acting alone or in combination, are fit for intended use, have been properly installed, and are operating correctly. This is an umbrella term that encompasses types of approaches such as qualification, commissioning and qualifica­tion, verification, and system validation. (TR60-2)

  • Verification Accredited Wholesale Distributors (VAWD)

    An accreditation governed by the U.S. National Association of Boards of Pharmacy for pharmaceutical wholesale distribution facilities indicating that they are in compliance with state and federal laws. (TR52)

  • 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)

  • Viable

    Alive and able to be cultured in the laboratory. (TR69)

  • Viable but Nonculturable (VBNC)

    Unable to be cultured in the prevailing test conditions but nonetheless capable of cell division and carrying out metabolic functions (TR69)

  • Viral Clearance

    Elimination of a target virus by removal of viral particles or by inactivation of viral infectivity. (TR41)

  • Viral Inactivation

    Reduction of virus infectivity caused by chemical or physical modification. (TR41) (TR83)

  • Viral Removal

    Physical separation of virus particles from the intended product. (TR47) (TR83)

  • Virus

    A simple, potentially pathogenic organism composed of a single type of nucleic acid (DNA or RNA) encased in a protein shell (called a capsid) and, in some cases, a lipid membrane (called an envelope). Viruses are incapable of independent replication and therefore must infect a host cell in order to propagate. (TR41)

    Obligate, intercellular, replicating, infectious agents that are potentially pathogenic, possessing only a single type of nucleic acid (either RNA or DNA). They use the host cells for propagation as they are unable to grow independently, for example by binary fission, and multiplying their genomic material. (TR47) (TR83)

  • Virus (Adventitious Virus)

    Unintentionally introduced contaminant viruses. (TR47)

  • Virus (Endogenous Virus

    Viral entity whose genome is part of the germ line of the species of origin of the cell line and can be produced in culture by cell lines from these species. (TR47)

  • Virus (Non-specific Model Virus)

    A virus used for characterization of viral clearance of the process when the purpose is to characterize the capacity of the manufacturing process to remove and/or inactivate viruses in general, i.e., to characterize the robustness of the purification process. (TR47)

  • Virus (Relevant Virus)

    A virus used in process evaluation studies that either is the virus, or of the same species as a virus known to or possible to contaminate the cell substrate or any other reagents or materials used in the production process. (TR47)

  • Virus (Specific Model Virus)

    Virus that is closely related to the known or suspected virus (same genus or family), having similar physical and chemical properties as those of the observed or suspected virus. (TR47)

  • Virus Preparation

    According to the mode of preparation the following terms are used:
    Crude Virus Preparation: A virus preparation that has undergone minimal processing post propagation. The virus is usually separated from cells which are lysed as the result of virus replication or are freezed/thawed in one or several cycles to release the virus from infected cells. The preparation is typically purified from cell debris by low speed centrifugation.
    Purified Virus Preparation: A virus that has undergone purification process by one or more techniques, such as density ultracentrifugation, chromatography or membrane adsorber. The purity of the virus preparation varies depending on the purification technique and should be characterized by appropriate analytical methods. (TR47)

  • Virus Production Lot

    A virus preparation that is used directly in a clearance study. It can be crude or purified. Typically a large volume is produced, tested and qualified. This volume is divided into multiple aliquots for individual clearance studies. (TR47)

  • Virus Removal

    Physical separation of virus particles from the intended product. (TR41)

  • Virus Seed

    An initial virus stock produced after a new virus is introduced into a laboratory. Its purpose is to create a Master Virus Bank. (MVB) (TR47)

  • Viscosity

    A solution property that is a measure of the fluid’s resistance to deformation when acted upon by shear forces. (TR15)

  • Visible fiber

    A fiber-like particle with an aspect ratio ≥5 and a length >300 µm. (TR85)

  • Visible particle

    A particle with an aspect ratio of <5 and a length >100 µm. (TR85)

  • Visible Particle Range

    Particulate matter sized above the visible particle 70% probability of detection threshold are con­sidered in the visible range, typically >100-150 μm. (TR79)

  • Visually Clean

    Absence of materials that would adulterate a product when inspected with the eyes. (TR70)

  • Void Volume

    See Porosity. (TR45)

  • Volatile

    Evaporates easily; converts easily from a liquid form to gas. (TR45) (TR26)

  • Volumetric Throughput (Vmax)

    The maximum volume that can be processed through a filter area. It is the volumetric capacity of the filter for a given process fluid and generally expressed in L/m2. (TR41) (TR47)

  • Warning Letters

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