Glossary Terms (Simple List)
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Hemadsorption
Adherence of red blood cells to virus-specific antigens on the surface of infected cells. In cellbased in vitro assays the reaction is used as an end point for virus detection. (TR47) (TR71)
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Hemagglutination
A clumping together or agglutination of red blood cells. In the context of this Technical Report hemagglutination indicates presence of virus that binds to erythrocytes. (TR47)
The clumping of red blood cells by binding to virus particles. The hemagglutination reaction is used in cell-based in vitro assays as an end point for virus detection. (TR71)
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Henry’s Law Constant
Henry’s law can be put into mathematical terms (at constant temperature) as p=kH x c, where p is the partial pressure of the solute, i.e.. TBA in the gas above the solution, c is the concentration of the solute and kH is a constant with the dimensions of pressure divided by concentration. The constant, known as Henry’s law constant, depends on the solute, the solvent and the temperature. (TR55)
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HETP (Height Equivalent to the Theoretical Plate)
A measurement of column packing efficiency or integrity, calculated from the column height divided by the number of theoretical plates. (TR14)
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High Density-Polyethylene (HDPE)
A linear polymer, HDPE is prepared from ethylene by a catalytic process. The absence of branching results in a more closely packed structure with a higher density and somewhat higher chemical resistance than low-density polyethylene (LDPE). (TR55)
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High-Efficiency Particulate Air (HEPA) Filter
A type of air filter that must satisfy certain standards of efficiency such as those set by the United States Department of Energy (DOE). The air filter must remove 99.97% of all particles greater than 0.3 micrometer from the air that passes through it. (TR62) (TR70)
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Highly Hazardous Drug Active
A drug active that can cause serious adverse effects at typical doses. Those adverse effects are generally not related to the main therapeutic activity of the drug, and includes effects such as carcinogenicity, mutagenicity, genotoxicity, reproductive hazards, allergenicity, and cytotoxicity. (TR29)
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Historian
A type of database designed to archive automation and process data. (TR84) -
Historical Data
For purposes of this guidance, data on impurities or physical attributes from three or more consecutive, representative pre-modification batches. (TR38)
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Hold-Up Volume (Residual Volume, Nonexpellable Volume, Dead Volume)
Amount of fluid remaining in the syringe when the plunger has reached the end of travel within the barrel. (TR73)