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)

Refine Results
Filter By Technical Report Number
Filter By Technical Report Keyword
Filter By Technical Report Category
    Displaying results 1 - 50 of 53
  • 1
  • 2
  • »
Back Pressure
Residual pressure opposing the free flow of liquid or gas at the outlet side of the filter. (TR45) Pressure applied downstream of a filter or other piece of equipment. (TR26)
Source:
Bacteria
Single-celled, microscopic organisms typically with a cell wall and characteristic shape (e.g., round, rod-like, spiral or filamentous); lacking a defined nucleus (“prokaryotic”). (TR26)
Source:
Bioburden
The total number of microorganisms per unit of material prior to sterilization. (TR13) Total number of viable microorganisms on or in a health care product prior to sterilization. (TR22)(TR61)(TR62) A population of viable microorganisms in a fluid prior to sterilizing filtration. (TR26) A measure of the contaminating organisms found in or on a given amount of material before it undergoes a sterilization process. (TR45) (TR70) The number of detectable microorganisms (bacteria and fungi) with which an object is contaminated. It is measured in CFU (colony forming units). (TR47) The number of viable, contaminating microorganisms present on a product immediately prior to decontamination. (TR51) Viable microbial contaminants associated with personnel manufacturing environments (air and surfaces), equipment, product packaging, raw materials (including water), in-process materials, and finished products. (TR 67) (TR 69)
Source:
Bracketing Approach
A scientific approach for defining product/load characteristics (e.g., viscosity, container sizes, container fill volumes, item sizes, loading configurations) that are tested (in a qualification study or validation study) at upper and/or lower limits. (TR1) (TR61) A validation method that tests the extremes of a process or product. The method assumes the extremes will be representative of all the samples between the extremes. (TR26)
Source:
Bubble Point
The measured differential gas pressure at which a wetting liquid (e.g., water, alcohol, product) is pushed out of the largest pores of a wetted porous membrane, and a steady stream of gas bubbles or bulk gas flow is detected.(TR15) (TR26) The minimum pressure at which a wetting liquid is pressed out of the pore system of a membrane while forming a steady bubble chain. (TR41)
Source:
Bubble Point Test
A test to indicate the maximum pore size of a filter. The differential gas pressure at which a liquid (usually water) is pushed out of the largest pores and a steady stream of gas bubbles is detected from a previously wetted filter under specific test conditions. Used to test filter integrity with specific, validated, pressure values, wetting liquids and temperatures for specific pore-size (and type of ) filters. (TR26)
Source:
Cake
Capsule Filter
Compact, self-contained filter assembly. Generally, the whole assembly is disposable. (TR26) (TR41)
Source:
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)
Source:
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)
Source:
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)
Source:
Diffusive Flow
The movement of a dissolved gas across a liquidwetted membrane based on the concentration (e.g., gas pressure) differential. (TR26)
Source:
Diffusive/Forward Flow Test
A test to determine the integrity of a filter. [Synonym: diffusive flow test, forward flow test.] (TR26)
Source:
Downstream Side (of Filter)
The effluent side of the process step (filter). (TR45) The filtrate or outlet side of the filter. (TR26)
Source:
Effective Filtration Area
The total surface area of the filter available to the process fluid. (TR26)
Source:
Endotoxin
Lipopolysaccharides from the cell walls of bacteria, the most potent of which derive from Gram-negative organisms. When injected, they are known to cause a febrile, or fever-producing reaction that can cause severe patient reactions, and on occasion, can be fatal. (TR26) (TR44) Pyrogenic lipopolysaccharide component of Gram-negative bacterial cell walls. (TR69)
Source:
Extractable
A chemical component that is removed from a material by application of an artificial or exaggerated force (e.g., solvent, temperature, time). The term extractable is often erroneously used to describe a leachable. (TR14) (TR15) (TR26) (TR41) (TR45) Chemical substances that can be extracted from components of material process fluid contact surfaces by exertion of an exaggerated force (e.g., organic solvent, extreme elevated temperature, ionic strength, pH, contact time, etc.) Extractables may represent most but not all of the potential leachables that may be seen in process fluids. (TR66) Extractables are organic and inorganic chemical entities that can be released from a pharmaceutical packaging/delivery system, packaging component, or packaging material of construction under laboratory conditions. (TR54-4) Organic or inorganic chemical entity that is forced out of container closure system materials and components under laboratory experimental conditions. (TR73)
Source:
Filter (verb)
To pass a fluid through a porous medium whereby bacteria or other particles are removed from the fluid. (TR26)
Source:
Filter Efficiency
A measurement of how well a filter retains particles. It is usually expressed as the percentage, or ratio, of the retention of particles of a specific size by a filter. (TR26)
Source:
Filterability Test
A test to determine the suitability and sizing of a filter with a given fluid. (TR26)
Source:
Filtrate
Fluid that has been passed through a process step (filter). [Synonym: Permeate] (TR15) (TR26)
Source:
Filtration
A process of removing particles from a fluid by passing it through a permeable material, such as a membrane film. (TR41) The process by which particles are removed from a fluid by passing the fluid through a porous material. (TR26)
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:
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:
Gamma Irradiation
The process by which a material is rendered sterile by exposing the material to a radioactive source, such as Cobalt 60. (TR70) Ionizing radiation that can be used to sterilize a material. (TR26)
Source:
Gauge Pressure
The pressure measured by a pressure gauge. Typically expressed in units of psig, bar or kilopascal. (TR45) Gauge pressure is the difference between a given fluid pressure and that of the atmosphere. (TR26)
Source:
Hydrophilic
Literally “water loving.” A filter that will wet with aqueous solutions to allow flow at a low pressure differential. (TR26)
Source:
Influent
Fluid that flows into a process step. [Synonym: feed.] (TR26)
Source:
Inlet Pressure
The applied pressure entering the upstream side of the filter. [Synonym: influent, upstream or line pressure] (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:
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:
Mass Spectroscopy
An analytical test method for identifying the chemical composition of a sample by separating its gaseous component ions according to their mass and charge. (TR26)
Source:
Materials of Construction
Polymers or other materials that make up the components of the filter. (TR26)
Source:
Medium
In filtration, the porous material which retains particles as a fluid passes through during the process of filtration (TR26)
Source:
Membrane
A thin, microporous medium used to remove particles and microorganisms from a fluid stream under pressure. (TR26) Analytical technique to collect particles from a liquid sample on a membrane filter followed by manual examination (sizing and counting) with a microscope. (TR85)
Source:
Microorganism
Non-fiber Releasing
Refers to a filter that does not shed fibers into the filtrate. (TR26)
Source:
Outlet Pressure
The pressure exiting the downstream side of the filter. [Synonym: effluent or downstream pressure] (TR26)
Source:
Particle
Any discrete unit of material structure; a discernible mass having an observable length, width, thickness, size and shape. (TR45) (TR26) Foreign material which is unintended and either removable from the surface of a primary packaging component or freely moving within a filled and sealed pharmaceutical dosage form. The term particle is used interchangeably with “particulate” and “particulate matter” without any intended difference in meaning. (TR85)
Source:
Particulate
Permeability
The degree to which a fluid will pass through a permeable substance under specified pressure and temperature conditions. (TR41) (TR26)
Source:
Pore
The channel(s)/path(s) in a membrane through which a fluid or a gas may pass. (TR41) (TR26)
Source:
Porosity
The ratio of void volume to bulk volume of the filter media. (TR26)
Source:
Pre-Filter
Any filter placed upstream of the final filter. (TR26)
Source:
Pressure
Force applied per unit area, usually expressed as psi, mbar, kPa or kg/cm2. (TR45) (TR26)
Source:
Redundant Filtration
A type of serial filtration in which a second sterilizing-grade filter is used as a backup in the event of an integrity failure of the primary sterilizing filter. (TR26)
Source:
Serial Filtration
Filtration through two or more filters of the same or decreasing pore size, one after the other. (TR26)
Source:
Surface Tension
The tendency of the surface of a liquid to contract to the smallest area possible under defined conditions. It is expressed as dynes per centimeter. (TR26)
Source:
Surfactant
A soluble compound that reduces the surface tension of a liquid or reduces interfacial tension between two liquids (causing formation or micelles) or between a liquid and a solid. [Synonym:Wetting Agent] (TR45) (TR26)
Source:
Throughput
The amount of solution that passes through a filter, described as volume per membrane area. [Synonym: capacity.] (TR15) The amount of solution that passes through a filter. It is described as volume through the membrane area. [Synonym: capacity] (TR26)
Source:
    Displaying results 1 - 50 of 53
  • 1
  • 2
  • »