Regarding nitrogen purging

Dear All

I want to know that how we select the nitrogen dosing quantity (pre purging & post purging) in vial & ampoule etc. during filling

in the case of dry powder & liquid injection.



This process is called Nitrogen purging and blanketing.
You are doing this to expell the oxygen that is present in vials are ampoules thus increasing the stability of product. Then a layer of nitrogen is blanketed on top of the drug product, either sealed by a rubber bung or an ampoule.

-First find out the volume of your primary packing material (volume = pae r square H)
-Then purge the gas so a particular speed or capacity at with in that particular point of time in your machine it purges minumum 2 volumes of nitrogen into the primary packing material.

  • Then after you fill the product, gently blanket on the drug product with sterile nitrogen.

During blanketing you have to note it is gentle process. You should make sure that you will not spill your liquid product or sterile powder from your primary packing material.Your operators knows best.

There are no hard and fast rules for this. I really did not understand why you need to know about this.

Your operators are in a best position to do this along with your manufacturing chemists.
You have to trust and believe this parameter when the machine is under operation.
All you can only control is the nitrogen flow meter.
This is not visible at any point of time and neither it can be measured by stopping your machine.