Recovery in Method Validation

GOOD VALIDATION PRACTICE (cGVP) LABORATORY, METHOD AND ANALYTICAL VALIDATION
21

if no impurity is available. stop doing validation.

22

I have a question regarding the calculation of recovery when there is a pre-existing amount of analyte in the sample. We have two schools of thought on how to calculate this…wondering what the general consensus is…

  1. %Recovery= ((Actual calculated amount in recovery sample)/(Amount Spiked into the recovery sample+ calculated theoretical pre-existing amount (determined from unspiked sample evaluation)) )x 100%

  2. %Recovery=((Actual calculated amount in recovery sample - Calculated theoretical pre-existing amount)/ (Amount Spiked into the recovery sample)) x 100%

Thanks…

23

No,it is an example for understanding preparations only,

for impurities the lower concentration must be from LOQ Level, but not 80%.

the validation range in case of impurities should be LOQ Level to 150% of the specification.

80 to 150% or 120% levels normally followed in assay of major analyte

24

i’am waiting for the answer to this as well

25

correct method of calculation

%Recovery=((Actual calculated amount in recovery sample - Calculated theoretical pre-existing amount)/ (Amount Spiked into the recovery sample)) x 100%

Regards,
Bujji reddy k