By M.R.Shyam Sundar on Sunday, October 6, 2002 - 11:22 pm:
When the initial method validation is performed at ICH limit and on tightening the specification based on the trend[ Initial validation covers a linearity range form LOQ to 200% of the target including 2*LOQ, 3*LOQ and 4*LOQ], can we some on share the policy on revalidation of your organisation with respect to specific parameters particularly in case of tightening of the specifications.
By Anonymous on Monday, October 7, 2002 - 02:01 pm:
I'm sorry, your question is very unclear. Do you want to revalidate your method with tigher specifications? What organization are you referring to? Please clarify your question so we can help you.
By M.R.Shyam Sundar on Monday, October 7, 2002 - 09:28 pm:
After completing the method validation and based on the commercial batches trend, the specificaion is revised [ tightening ]. In that situation what are the all the minimum parameters are revalidated. This was what the point of discussion.
By Anonymous on Tuesday, October 8, 2002 - 07:32 am:
If you tightened the batch specifications, I don't see why you would have to revalidate any part of the method. Will the validated method work with the new specifications. The method validation has nothing to do with the batch specifications.
By David Blais on Tuesday, October 8, 2002 - 08:42 am:
I agree with Anonymous. If you are simply making the specifications tighter, you should not need to revalidate anything - all your batches should still pass the new specs. Widening the specifications, on the other hand, is completely different.
By pds on Thursday, October 10, 2002 - 05:14 am:
I'm also having the similar doubt and herewith find an example.
Ex. Consider the parameter "Linearity " :
As per the ICH , the linearity should have minimum 5 concentrations and with a minimum range of 80 to 120% of the test concentration.
Ex: Spec limit is 1000 ppm , I have demonstrated the linearty from LOQ level to 120% ie; 30ppm(say), 200 ppm, 400 ppm, 600 ppm, 800 ppm, 1000 ppm, and 1200 ppm are the points selected.
My reveised spec is now 500 ppm.
As per my validation data I have only 3 points, but ICH say requirement of 5 points.
So, revalidation is required or not.
ie; at 400 ppm, 450ppm, 500ppm, 550 ppm and 600 ppm.
Thanks in advance.
By Anon. on Thursday, October 10, 2002 - 05:28 am:
Your current linearity covers the range of 80% to 120% of the specification so no revalidation is necessary. The key word in the ICH guidelines for linearity is a "minimum" range of 80% to 120% as long as your validated linearity exceeds this minimum requirement no additional validation is necessary.
By pds on Friday, October 11, 2002 - 05:30 am: