PDA Technical Glossary

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)

A process where there are no streams flowing into or out of a controlled volume, as opposed to a continuous process. In a batch filtration process, the feed solution is reduced in volume due to permeation of filtrate through the filter. There is no continuous addition of feed solution to the feed vessel. (TR45)

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)

A filtration operation resulting in a significant rise in filtrate turbidity accompanied by a small increase in differential pressure. This occurs when the adsorptive capacity of the filter is reached, resulting in the passage of particles smaller than the pore size of the filter that would normally be removed by adsorption. (TR45)

Small bacteria (0.3–0.4 &mum in diameter by 0.6–0.1 &mum long) used to challenge a sterilizing grade filter during validation testing. [Formerly Pseudomonas diminuta](TR45)

The constant of proportionality of the material as defined by Darcy’s Law. (TR45)

The effluent side of the process step (filter). (TR45) The filtrate or outlet side of the filter. (TR26)

The fluid and all constituents in a fermentation vessel prior to separation. (TR45)

Endotoxin detection and quantitation can be accomplished at high sensitivity and specificity using reagents manufactured from Limulus Amebocyte Lysate, a biological reagent prepared from horseshoe crabs and offered in a variety of formulations. (TR45)

The part of the filter through which fluid passes that retains particles during filtration. (TR45)

A microbe; a free-living organism too small to be seen by the naked eye. (TR45) (TR26)

Reduction of microbial contaminants to safe levels as judged by public health requirements for the specific country. (TR13) A significant reduction in bioburden, achieved in chromatography by the use of bactericidal agents, such as sodium hydroxide (NaOH), hydrochloric acid (HCl), ethanol (EtOH), and isopropanol (IPA). (TR14) The process of reducing microbial levels by treatment at less than defined sterilizing conditions. Typically water at 80 °C or a chemical treatment is used to perform sanitization of process components. (TR45) A process that reduces the number of viable microorganisms to a defined level. (TR61) (TR69)

Studies used to select a particular type and grade of filter media. (TR45)

Water purified by distillation or a purification process that is equivalent or superior to distillation in the removal of chemicals and microorganisms and contains no added substances. (TR45)