March 2013


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Pharmaceutical Stability Discussion Group <[log in to unmask]>
Thu, 14 Mar 2013 11:58:41 -0400
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Hi everyone,
I hope this email finds you all doing well.  This is the first time I am posting on this message board and I am excited to hear your responses!

I have a couple industry related questions regarding sampling and stability testing of injectable (fluid) samples.  We are currently considering our drug product homogeneous.  If you, anyone on your team, or someone else you can direct me to, has guidance on this topic, it would be much appreciated.  We know that it is common industry practice with regard to solid dosage products to make a composite sample (beginning/middle/end), which should be homogeneous and statistically representative of the lot/batch blend.  When I worked in solid dosage, we put all collected beginning / middle / end samples in the stability chamber and then made a composite out of those samples at a specific time point pull.  This composite was then used for testing at the various pulls.
I have questions regarding stability testing of our injectable (fluid) product.  The discussion is around what is appropriate for sample pulls of an injectable product and whether there is a defined standard to make sure the lot/batch is tested in a way that one would feel comfortable that it is representative of the entire lot/batch.
Should samples be pulled at the beginning, middle and end (B/M/E) for an injectable product or, since we consider the entire batch homogeneous, only pull one sample at the end of the batch?
If B/M/E samples should be pulled, do we keep all of these samples separate when we place them in the stability chamber or can we make a composite just prior to placing them in the chamber?
If B/M/E samples are kept separate, do we need to test them all separately at each time point pull?  Or, can we make a composite of the B/M/E samples just prior to testing?
Is the answer clear or does it depend on other factors like:  overall size of the batch that is made;  whether your company considers the batch homogeneous ; etc?
Some of these scenarios will obviously lead to more space being taken up in the stability chambers and require much more testing to be performed (3 samples at each time point instead of 1 composite sample). 
If anyone has any experience or could lead me in the right direction with injectable products, it would be very helpful and appreciated. 

Thank you!


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