I got 88.0 % assay for a drug in HPLC analysis for same
injection i got 40.0% related substances is it possible?
what is the relation between results of assay and purity?
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Answer / muralikrishna ch
Practically the above case is not possible. I understood
related substances as impurities. If your sample is having
40% related substances your sample probably having assay
less than 60%.
| Is This Answer Correct ? | 14 Yes | 1 No |
PURITY IS QUALITATIVE ANALASIS
BUT ASAAY IS QUANTITATIVE ANALASIS.
EXP:-
CIPROFLOXACINE EXP
THIS PRODUCT PURITY IS 99.5% BUT ASSAY IS 99.8%
THE SAME PRODUCT PURITY IS 99.5% BUT ASSAY IS 80.0%
THE SAME PRODUCT PURITY IS 99.5% BUT ASSAY IS 50.0%
BECOUSE PURITY IS NOT DEPEND UP ON THE ASSAY.
| Is This Answer Correct ? | 11 Yes | 1 No |
Answer / s chatterjee
in Gabapentin, Imp A has a RRF of 12.6 i.e. against gabapentin standard. Say Gabapentin has degraded 12 % i.e. 88 % assay ( quantitative only) . When rel subs was calculated the Imp A against the gabapentin standard will give an quantitative value of 36 %. however, in reality as the correction factor is 12.6 then this comes to 36/12 = 3 % in reality.
Therefore it is important to know that the correction factor of related substances had been established against the drug used for quantification. Response of degradation products varies significantly from the drug candidate under UV.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / falguni patel
Ya that may be possible. In purity, we compare area of our
main component with respect to impurities, while in assay
we compare it with standard. So in purity % of area will
devide with impurities.
| Is This Answer Correct ? | 2 Yes | 3 No |
Answer / a.prabhakar
May it is possible above case. Related substances is qualitative test but purity/assay is quantitative test.In quantitative test sample area compare with standard area.
| Is This Answer Correct ? | 1 Yes | 3 No |
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