Dirty and Clean equipment holf time study

Dear All, Pls provide your input

Do CEHT and DEHT need to validate in each cleaning validation study?
What are the parameter to be considered for identification of worst case molecule for hold time studies ?
If I am performing only BET evaluation after cleaning, for cleaning validation, and not evaluating bio burden, is it fine? (As we manufacture injectable, the cleaned equipment will go for sterilization after cleaning, hence is it required to perform bio burden level after cleaning, in cleaning validation?)

1st question: Yes, unless you can demonstrate that the cleaning validation study is similar to a previous study (same equipment…)

2nd question: Same criteria as the full CV study

3rd question: Not all bacteria produce endotoxins so bio burden study would be required (before and after cleaning)

Im not agreeing with Chemist.
DEHT and CEHT are required only on single CV study (refer PDA tech report)

Generally, worst case molecule shall be identified from its toxicity (low theraputic dose) and solubility.

If you have established a validated sterilization cycle, no need to go for monitoring of bioburden and endotoxin as long as your WFI bioburden trends are well with in the control.

@sandipsabhani To determine the worst case product you can choose a product with max toxicity, lowest MACO values, thickest / hardest to clean / sticky / oily or just products with historical cleaning failures. You have to establish clean and dirty hold times everytime you have a new product. I would do a complete set of samples at 0 time and then another after the clean hold time is over. Usually just rinse micro and endo samples are sufficient but if you do micro swabs it will look good as usually the temp. of water should kill most microbes in rinse samples (although i am not an expert on that but some food for thought).

Hope this helps.

Dear ramyaraj725,

As you have mentioned DEHT and CEHT are required only on single CV study (refer PDA tech report), It will be appreciable if you please specify the point no. because I have gone through TR 29, but unable to find the the same.

Dear All
I dont think so for clean hold time study to validate for all the cleaning validation batches. Because for clean hold time studies, the purpose is only to demonstrate that equipment remains clean for after cleaning. It can be done for highest surface area equipment train once and can be reevaluated on some periodic basis.
Thank you

I think the purpose of clean hold time study is to demonstrate the capability of equipment storage environment to maintain equipment cleanliness up to certain period; after completing CHT study established CHT priod is the limit to allow equipment can b keep idol, no further cleaning required between period for re-use of equipment.

DHT is totally different; Here we need to demonstrate the capabilities of cleaning method; Existing cleaning method capable to clean the certain period dirty equipment. As we know unclean equipment become more rusty and wall sticked material becomes more harder and not easy to clean. Established time period during DHT study will used to design SOP to allow the equipment in dirty condition after use.

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