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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 #

  • Naturally Occurring Endotoxin (NOE)

    Endotoxin prepared from Gram-negative bacteria produced under defined conditions and with minimal nonchemical processing, e.g., centrifugation and filtration.(TR82)

  • Needle (Cannula)

    A thin, hollow, metal tube commonly used with a syringe to inject substances into the body. (TR73)

  • Needle Shield (Needle Cover)

    Rigid or flexible polymeric substance used to seal and protect the needle. (TR73)

  • Needle-Safety Device

    A safety feature or mechanism that effectively reduces the risk of an exposure incident (e.g., accidental needlestick). (TR73)

  • Negative Control

    A test article used to assess the performance of an assay in the known absence of a targeted microorganism or nucleic acid. Negative controls are used to minimize a risk of false positive results, which could occur due to non-specific signals. (TR50)

  • Nest (Tub Nest)

    Rigid plastic support placed into a tub to keep syringes upright with sufficient separation to allow for easy manipulation by manual or automated fill-line systems. (TR73)

  • New Drug Application (NDA)

    An application filed with the FDA used for the regulation and control of new drugs in the Unit­ed States; the goal is to provide enough infor­mation to permit the FDA reviewer to reach the following key decisions: whether the drug is safe and effective in its proposed use(s), and wheth­er the benefits of the drug outweigh the risks; whether the drugs proposed labeling (package insert) is appropriate, and what it should con­tain; whether the methods used in manufactur­ing the drug, and the controls used to maintain the drug’s quality are adequate to preserve the drug’s identity, strength, quality, and purity. (TR56)

  • Nominal Molecular-Weight Cutoff (NMWCO)

    A manufacturer’s measure of an ultrafiltration membrane based on a defined solute-retention coefficient. (TR15)

  • Nominal Pore Size Rating

    A filter rating with an arbitrary value, indicating a particulate size range at which the filter manufacturer claims the filter removes some percentage. Nominal ratings vary from manufacturer to manufacturer and may not be suitable to compare filters among manufacturers. Processing conditions, such as operating pressure and concentration of contaminant may have a significant effect on the retention efficiency of the nominally rated filters. (TR41)

  • Nominal Value

    The assumed activity of an endotoxin preparation, dilution, or "spike"; based on label-claim information.(TR82)

  • Nonclinical Laboratory Study

    For this report, nonclinical laboratory study means in vivo or in vitro experiments, in which test arti­cles are studied prospectively in test systems under laboratory conditions in order to determine their safety. The definition does not include: studies us­ing human subjects or clinical studies, field trials in animals, or any basic exploratory studies carried out to determine whether a test article has any po­tential utility or to determine physical or chemical characteristics as described in ICH S6 and 21 CFR Part 58 (GLP).
    Note: Also referred to as Preclinical, Toxicity or “Tox” studies. (TR56)

  • Non-Condensable Gases

    Air and other gases that will not condense to liquid state, thereby not releasing latent heat under the conditions of sterilization. (TR01)

  • Nonconformity (ANSI def.)

    A departure of a quality characteristic from its intended level or state that occurs with severity sufficient to cause an associated product or service not to meet a specification requirement. [Synonym: Defect] (TR43)(TR76)

  • Nonconformity (ISO def.)

    A condition of any product or component in which one or more characteristics do not conform to requirements. Includes failures, deficiencies, defects, and malfunctions. [Synonym: Defect](TR43)(TR76)

  • Nonconformity Classifications

    Critical: A Nonconformity that is likely to result in personal injury or potential hazard to the patient. This classification includes any nonconformity that compromises the integrity of the container, and risks microbiological contamination of a sterile product.
    Major A: A Nonconformity leading to serious impairments, for example, a malfunction that makes the packaging unusable.
    Major B: A Nonconformity leading to impairments of a lesser degree, for example, reduced efficiency in production.
    Minor: A Nonconformity that does not impact product quality or process capability.
    N/A: An imperfection classification that is less than the size, magnitude and impact of a nonconformity is considered not applicable. Therefore an imperfection that is considered to be non-applicable is acceptable.(TR43)

    Critical: A nonconformity that risks personal injury or potential hazard to the patient. Any nonconformity that risks container closure in¬tegrity is assigned to this classification.
    Major A: A nonconformity leading to serious container impairments, e.g., a malfunction making packaging unusable.
    Major B: A nonconformity leading to contain¬er impairments of a lesser degree, e.g., reduced efficiency in production.
    Minor: A nonconformity that does not impact product quality or process capability.
    N/A: Imperfections that are considered to be nonapplicable or nondefects and are therefore acceptable.(TR 76)

  • Non-fiber Releasing

    Refers to a filter that does not shed fibers into the filtrate. (TR26)

  • Nonfiber Releasing Filter

    Nonfiber-releasing filter means any filter, which after any appropriate pretreatment, such as washing or flushing, will not release fibers into the component or drug product that is being filtered. All filters composed of asbestos are deemed to be fiber-releasing filters. (TR45)

  • Noninferiority

    A comparison with the primary objective of showing that the result from one method is not inferior to the method being compared. This is usually demonstrated by showing that the true difference is likely to lie above the lower equivalence margin. (TR57)

  • Nonspecific 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 general viral clearance capacity of the purification process.) (TR41)

  • 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)

  • Normal Dose

    The therapeutic dose of a product as given on the approved product labeling. (TR29) (TR49)

  • Normal Operating Range (NOR)

    A defined range, within (or equal to) the Proven Acceptable Range, specified in the manufacturing instructions as the target and range at which a process parameter is controlled, while producing unit operation material or final product meeting release criteria and CQAs. (TR60) (TR60-2)

  • Nosocomial Infection (hospital-related infection)

    An infection acquired in a hospital or other healthcare institution that was not present at the time of admission; the most common sites of infection are the urinary tract, surgical wound and lower respiratory tract and bloodstream. The vast majority of nosocomial infections are associated with use of invasive medical devices (e.g., urinary tract catheters, ventilators and central venous catheters). (TR67)

  • Nuclease

    An enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids. (TR47)

  • Nucleic Acid Amplification Technique (NAT)

    A method for detection, and in some cases, quantification of target organisms via detection of organism specific nucleic acid. PCR or polymerase chain reaction is a common NAT method that is based on amplification of targeted sequences using primers and specialized DNA polymerases. (TR50)

  • Nucleic Acid Sequence Based Amplification (NASBA)

    An isothermal amplification method targeting RNA in which amplifications of RNA occurs via DNA intermediates. Each of the DNA templates can make 100 to 1000 copies of RNA amplicons, potentially resulting in the production of greater than a billion amplicons. (TR50)

  • Nucleic Acid Standard

    A sample with a precisely measured content of specific nucleic acid. A nucleic acid standard can be serially diluted to assess the limit of detection of an NAT assay or to create a standard curve for Q-PCR to determine the concentration of target nucleic acid. (TR50)

  • Objectionable Microorganism

    According to 21 CFR 211.113 objectionable microorganisms can be: product related or recipient related. Please see glossary for "product related" or "recipient related" for additional information. (TR67)