Bioequivalence and Bioavailability Forum

Dear All,

We are facing some of the problem with the Aspirin. I just want to confirm that the methodology adopted by us is correct or not.
We have collected the blood in the vacationer which contains some amount of sodium fluoride with K2EDTA as an anticoagulant. After collecting the blood the samples are centrifuged and after the separation of the plasma the samples are stabilized with potassium fluoride (equivalent amount).
This all process is completed within the 30 minutes from the collection of separation till the storage at specific condition.
After searching some other methods we come to know that some other people has used different agent as a stabilizer.
Now my question is:
1. Does the change in the stabilizer agent affect a lot in terms of outcome? Or which is the best stabilizer. (Potassium fluoride or Di Sodium hydrogen Phosphate)
2. My method has produce 98% ISR results however the RLD performance is different in all two pilot study and last conducted pivotal study.
3. Does the time take for the collection till the centrifugation affect a lot even it is completed within the 30 minutes and initially collected in stabilized material?
We are unable to get the reason for change in RLD results in all three studies (two pilot one pivotal). Does it sense that the adopted method is fail to prevent conversion in salicylic acid?

Regards,

compliance