How to fix the concentration for RS by HPLC
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Answer / venkat
Concentration of sample= estimated LOQ concentration (µg/mL) x 1/desired LOQ (%) x 100
| Is This Answer Correct ? | 45 Yes | 3 No |
Answer / dhilip anand
To determine the sample concentration that gives an
acceptable LOQ
(Signal to Noise ratio, S/N) in low level spike
concentrations. The sample concentration should
be low enough to maintain linearity and precision, but high
enough to achieve the desired LOQ.
For example, if the ICH reporting limit for this drug
product is 0.1%, the LOQ of the method
should be less than 0.05% (i.e., desired LOQ, in %). By
using spike sample solutions of very
diluted concentrations for the significant related
substances, estimate the concentrations that give
a S/N of about 10 for the significant related substances.
This estimated concentration is the
approximate LOQ concentration (i.e., estimated LOQ
concentration, in µg/mL).
The following equation can be used to estimate the target
sample concentration for the method:
Target sample concentration =
estimated LOQ concentration (µg/mL) x 1/desired LOQ (%) x 100
Hi this above answer probably worksout since most of the
drug's TDI(dose) will be <1g so desired LOQ % is regarded as
0.05% for reporting threshold with 0.1% and anybody suggest
what will be the desired LOQ % when reporting threshold is
0.05% i.e., if TDI is >1g as per ICH??? Can correct the
above answer if m wrong???
| Is This Answer Correct ? | 23 Yes | 1 No |
Answer / sdfgrt
Concentration of sample= estimated LOQ concentration
(µg/mL) x 1/desired LOQ (%) x 100
Any referance for this
| Is This Answer Correct ? | 11 Yes | 0 No |
Answer / rajkumar
Please any one clearly explain the with an example.
| Is This Answer Correct ? | 9 Yes | 1 No |
Answer / sanjay prajapati
It is very simple let keep the concentration which gives
LOQ value 0.05%
| Is This Answer Correct ? | 5 Yes | 0 No |
Answer / ram
The common procedure for fixing the LOQ is assuming u r specification as 100 % and we have to achieve LOQ below 50% of specification, here impurities are may be known or unknown.
for exm. known imp limit is 1.0 % then u should try to get LOQ below 0.5%, however if u try for very low level then it is well n good.
All unknown impurities will have spe of 0.1% limit and we have to do validation of unknown with active .
| Is This Answer Correct ? | 4 Yes | 1 No |
Formula=Estimation LOQ concentration (PPM)X1/Desired LOQ concentration (%)X100.
For example as per ICHQ3B our product Reporting threshold was 0.05% this is called Desired LOQ concentration.First initially we fix sample concentration as 500 ppm.This is 100%,as per this, 0.05% LOQ ppm was 0.25 ppm this is Estimated LOQ concentration.
| Is This Answer Correct ? | 1 Yes | 1 No |
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