Inherent interventions. Inherent interventions are operator-performed activities that are an integral part of the process without which the process
can either not occur or cannot be adequately controlled. Examples of inherent interventions are: the initial setup of the
aseptic process (which is a series of manual interventions to make the equipment ready for use); product and package resupply;
monitoring of process operation (i.e., weight or volume checks and in-process environmental sampling); recordkeeping; and
any other activity whose execution is needed to keep the process running.
The frequency of inherent interventions is largely fixed by external factors and not subject to significant variation once
initially established. The frequency of their execution may be defined in procedures or by operational requirements. The following
inherent interventions are a required part of every aseptic process because their absence would prevent its execution:
- The initial aseptic assembly of a fill line in preparation for filling entails essentially the same interventions for each
lot (and perhaps for other similar products in the same scale container).
- Component replenishment is a function of line speed and sterilization quantity. Once defined, it should be constant for similar
containers and closures.
- The frequency of weight or volume checks is directly linked to the ability of the filling equipment to maintain constant delivery,
and is largely fixed by standard operating procedure (SOP).
- Environmental-monitoring frequency is defined in sampling SOPs that are rarely adjusted once established, although excessive
monitoring, which generally is associated with regulatory inspections, has little justification.
Inherent interventions are also an integral part of every process simulation and occur at essentially the same rate during
a filling process as they would for a product lot with the same container components. Some firms increase the frequency of
environmental monitoring during process simulations, but it is safe to say that the execution rate for inherent interventions
in a process simulation is nearly the same as that experienced during a product fill for the same container-closure system.**
The setup of the aseptic processing line entails the assembly and positioning of sterilized product-contact parts on the filling
machine or line. Containers and closures are introduced and fed through the equipment, and adjustments are made as necessary
to ensure reliability of operation. Product material (liquid or powder) is then connected to or introduced into the equipment,
and initial weight or volume settings are established. The setup is essentially one lengthy inherent intervention from beginning
to end. The intensity of the necessary activities is such that setup represents the greatest potential risk of contamination.