PDA Technical Glossary

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.

(Please select "All" to restart a filtered Search)

  • All
  • 0
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • A
  • B
  • C
  • D
  • E
  • F
  • G
  • H
  • I
  • J
  • K
  • L
  • M
  • N
  • O
  • P
  • Q
  • R
  • S
  • T
  • U
  • V
  • W
  • X
  • Y
  • Z
Anaerobic Microorganism
A microorganism that does not utilize oxygen as the final electron acceptor during metabolism; microorganism that will grow only in the absence of oxygen. (TR62)(TR22)
Source:
Aseptic Processing Simulation (APS)
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)
Source:
Elastomer
Thermoplastic material formulation (that may or may not contain rubber/natural latex) derived from elastic polymer; often used interchangeably with the term “rubber.” (TR73)
Source:
Flow Decay Test
An experiment to determine flow rate and throughput of a filter type or combination of filters on a specific liquid, usually by using a small area filter, to determine the sizing of a filter system by extrapolation. (TR45)
Source:
Flow Rate
The volumetric rate of flow of a solution, expressed in units of volume per time (e.g., L/min or gal/day). (TR15) (TR26)
Source:
Flow-through
Effluent that may contain the product that is not retained by chromatography resin during column loading. (TR14)
Source:
Foulant
Solute or suspended solid that interacts with the membrane causing a decrease in performance (see Fouling). (TR15)
Source:
Fouling (or Clogging)
Adsorption or interaction with components in the feed stream resulting in a decrease in membrane performance. Generally, fouling can be reversed by cleaning the membrane. (TR15) The result of solutes blinding or blocking membrane pores. It is observed as a decrease in the flux (at constant pressure) or an increase in the filtration differential pressure (at constant flux). (TR26)
Source:
Integrity Test
Test to determine the functional performance of a membrane filter or container/closure system. (TR22) A nondestructive test used to predict the functional performance of a filter. (TR45) A nondestructive physical test that can be correlated to the bacterial retention capability of a filter/filter assembly. (TR26)
Source:
Integrity Testing
A method of determining if a membrane or filter is physically intact and free from gross defects. (TR15)
Source:
Leachable
A chemical component that migrates from a contact surface into a drug product or process fluid during storage or normal use conditions. The term leachable is often erroneously used to describe an extractable. (TR14) (TR26) Leachables are organic and inorganic chemical entities that migrate from a packaging/delivery system, packaging component, or packaging material of construction into an associated drug product under normal conditions of storage and use or during accelerated drug product stability studies. Leachables are typically a subset of extractables or are derived from extractables. (TR54-4) Chemical substances that are leached, from product-contact or non-product-contact materials, under typical process conditions and detected in final dosage. Leachables may be a subset of extractables, and can include their reaction or breakdown products. (TR66) Organic or inorganic chemical entity that migrates from pharmaceutical container closure system components into a drug product formulation. (TR73)
Source:
Lenticular Filters
A filter made up of a series of biconvex cells that are stacked on top of one another with rings between them to prevent bypass between the cells. End-caps are then placed at the top and bottom of the assembly and are held in place with a central core. [Synonyms: Lenticular Cartridge, Modules, Filter Elements, Filter Devices] (TR45)
Source:
Mandrel
Parison
Pressure Shock
An unanticipated rapid increase in fluid flow. [Synonym: Hydraulic Shock] (TR45)
Source:
Pressure Shock (Backward Pressure Shock)
Rapid backward fluid flow that may result in filter rupture. (TR45)
Source:
Pressure Shock (Forward Pressure Shock)
Rapid increase in forward fluid flow that may dislodge particulates. (TR45)
Source:
Recovery
The mass of desired solute in the final product solution (either permeate or retentate, depending on the process), divided by the mass of the desired solute in the initial feed solution, expressed as a percentage. [Synonym: yield] (TR15) (TR45) A measure of the amount of analyte carried through the entire sample preparation and assay procedure and expressed as a percentage of the nominal concentration. (TR57)
Source:
Recovery Study
A laboratory study combining the sampling method and analytical method to determine the quantitative recovery of a specific residue for a defined surface. (TR29) A laboratory study combining the sampling method and analytical method to determine the quantitative recovery of a specific residue for a defined surface. (TR49)
Source:
Rejection
The ability of a filter to exclude solutes or particulate matter from passing through. (TR45)
Source:
Screening Studies
Studies used to select a particular type and grade of filter media. (TR45)
Source:
Stirred-Cell Filtration
A surrogate for tangential flow filtration where shear is achieved by rapidly stirring the solution immediately adjacent to the membrane. Typically the stirring is accomplished by mechanical means, such as through the use of a stir bar or impeller. (TR15)
Source:
Water Activity (Aw)
Water Activity, Aw is the ratio of the vapor pressure of water in a product (P) to the vapor pressure of water in a product (P) to the vapor pressure of pure water (Po) at the same temperature. It is numerically equal to 1/100 of the RH generated by the product in a closed system. It is a measure of the free or available moisture in the material. Note: Water activity ≠ water content. RH can be calculated from direct measurements partial vapor pressure or dew point, or from indirect measurements by sensors whose physical or electric characteristics are altered by the RH to which they are exposed. Microorganisms need available water within a pharmaceutical product, as well as nutrients and minerals, to proliferate. Water activity, and not water content, is a better measure of the free water, in contrast to bound water that microbial cells require for metabolic activity and osmotic regulation. Effects of reduced Aw on microbial growth include a longer lag phase, slower growth rate, lower numbers of organisms in the stationary phase, and reduced microbial toxin production; below a specified Aw for an organism, microbial growth will not occur. (TR55) (TR67)
Source: