Hold Time Study Approach……
It is an expectation of regulatory organizations that companies establish and monitor clean and dirty equipment hold times for manufacturing equipment as part of their cleaning validation program.
Although the regulatory agencies expect manufacturers to document and address hold times, they do not describe a process for establishing the hold time.
Dirty Hold Time
The maximum amount of time equipment can be left soiled before cleaning. Dirty hold time is usually defined as the time between the end of manufacturing and the beginning of the cleaning process.
Dirty hold times are regarded as “critical elements” in the cleaning process, especially for topicals, suspensions, and bulk drug operations where the drying of residues may directly affect the efficiency of a cleaning process.
In practice, dirty hold times are typically based on the requirements and time frames of the manufacturing process.
Typically, three consecutive applications of the cleaning procedure incorporating the maximum required dirty hold time should be performed and shown to be successful to prove that the method is validated.
The longer a product is held “clean” before use increases the chances of it becoming contaminated, and the risk of microbial growth on the equipment during storage.
Evidence that routine cleaning and storage does not proliferate microbial growth is required.
Clean Hold Time
The maximum amount of time equipment can be left clean before use. Clean hold time is generally considered to be the time between the completion of cleaning and the initiation of the subsequent manufacturing operation.
The main factors affecting the clean hold time are the storage conditions and the room classification / qualification.
In its Guide to Inspection of Validation of Cleaning Processes, the US Food and Drug Administration considers identifying and controlling the length of time between the end of processing and each cleaning step to be critical elements of the cleaning processes.