I am performing hold time study for filter bag of fluid bed dryer. In the previous study, my ex-colleagues concluded that the clean hold time is 15 days. I am new to cleaning validation and this makes me confused:
- What is the strategy for conducting the clean hold time study? I mean which day(s) should be selected to sampling? I see some companies choose days 1st, 3rd, 7th and 15th, but I really don’t know what is the basis of these selection.
- What if the test results show the presence of microorganism in the day 7th and their absence in the day 15th? If we conclude that the clean hold time is 15 days, then we manufacture drugs in the day 10th, how can we assure that our products will not be contaminated?
Thank you for taking the time to look into my matter.