Difference between Bromobutyl Rubber Stopper and Graybutyl Rubber Stopper

GOOD MANUFACTURING PRACTICE (cGMP)
1

Can any body help me finding difference between Bromobutyl rubber stopper and Graybutyl rubber Stopper. Is there any difference with quality aspects.

2

There can be but it is up to you to disprove it! One of the related substances is a reaction product between the container closure system (a Lyo stopper) and the API. In my case the API was dissolved in dilute acetic acid and the container was a vial with a lyo stopper. The vial acted like a reflux engine and washed the residual rubber constituents down with the acetic acid so it reacted with the API. Thus, the API potency decreased with both time and temperature.

The FDA has issued a guidance on container closure systems.

3

You need to contact the stopper vendor. You are listing two different and unrelated items.

  1. Bromobutyl is the specific type of butyl rubber. It is butyl that is halogenated with bromine.
  2. Greybutyl is the color of the stopper. It could be bromobutyl, chlorobutyl or even non-halogenated butyl. As is stated by Boomer_Chemist, you need to prove test the specific closure. Please note: two grey bromobutyl rubber stoppers could have very different extractables or physical properties.
1 Like