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Dear all,
I have the following question, that it will be much appreciated if you
can help me to answer it.
Can we omit Any point of the calibration curve except the LLOQ and the
ULOQ, if it has a negative effect on the regression equation
parameters and other points in the curve; providing that the
calculated deviation of this point on the new regression equation
(after omitting this point from the curve) is more than 15% from the
nominal value; and the total number of rejected standards is not more
than two of eight (75% accepted ratio).
Is there any guideline that deal with this issue?
Thank you
Rana
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You mean the point is acceptable but other points are not if the point
is left in?
Generally, as you have stated not the LLOQ or ULOQ, if you reject more
than 1 they cannot be sequential. If you play the game of getting rid
of the LLOQ or ULOQ get ready for a QA nightmare. There is a minimum
number of points in general and it will vary re the model you use.
Six surviving points is a good target. What does your SOP require.
Look at the 2001 guidance ( FDA website), Findlay et al paper on
curves and key element of small and large molecule assays (aaps
website).
--
Edward F. O'Connor
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Dear Rana,
Regarding deleting points from a standard curve, first read the FDA
guidance on Bioanalytical Method Validation (you may already have done
this)
http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM070107.pdf
Second have an SOP or a formal documented process for the specific
method that has objective criteria for removing ("censoring") points
from a calibration curve, and includes limitations. Your suggestions
are definitely on the right track.
-Tom
Thomas L. Tarnowski, Ph.D.
Bioanalytical Development / Analytical Development
Elan Pharmaceuticals, Inc.
800 Gateway Boulevard
South San Francisco, CA 94080
thomas.tarnowski.-a-.elan.com
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