For a component, a family is a range of components manufactured from the same materials using the same manufacturing process at the same manufacturer but may be of different sizes/shapes. An example is polypropylene connectors molded into different shapes (e.g. L, T or Y) from the same resin. Another example is silicone tubing where the family may be platinum-cured silicone tubing of varying internal diameter measurements. Platinum-cured silicone tubing manufactured by a different manufacturer is not part of the family nor is peroxide-cured silicone tubing. The experimentally obtained extractables data can be applied to other components in the family by a conversion factor based on surface area (or weight).
For filters, a component family can be defined as filters of different sizes manufactured from the same filter membrane type and raw materials in the housing and connectors. The experimentally obtained extractables data can be applied to other components in the family by a conversion factor based on the surface area. This is a simplified conversion model, as extractables originating from the housing and connectors are not related to the membrane surface area and thereby scale differently.
For sensors and valves, a component family is a range of components manufactured from the same materials of construction but in different proportions or different sizes/shapes. The experimentally obtained extractables data can be applied to other components in the family by a conversion factor based on the total surface area of fluid-contacting parts or weight, as appropriate. This is a simplified conversion model, as extractables originating from the different sub-components scale differently.
For bags, the preferred study design is to test each component of the bag assembly individually (e.g. film, ports, tubing, impeller, sensors, filters, etc.).
Similar to a component family, an assembly family can be defined. A bag assembly family is a set of bags manufactured from the same components but in different ratios. Examples are bags that differ in size, number of ports or length of attached tubing. The extractables profile for the assembled bag will be obtained by combining the extractables data for each component.
Alternatively, if an assembled bag was tested as a representative of an assembly family, the experimentally obtained extractables data can be applied to other bag assemblies in the product family by a conversion factor based on the film surface area. This is a simplified conversion model, as extractables originating from the other components are not related to the film surface area.
For chromatography columns, the preferred study design is coupons of each material. A column-assembly family is a set of columns manufactured from the same materials of construction but in different sizes/ratios.
Alternatively, if a column was tested as an assembly, the experimentally obtained extractables data can be applied to other columns in the assembly family by a conversion factor based on the surface area of the main fluid-contacting part(s). This is a simplified conversion model, as the ratio between materials varies with column size.