How do you decide sample quantity of water Content for inhouse method?

GOOD VALIDATION PRACTICE (cGVP) LABORATORY, METHOD AND ANALYTICAL VALIDATION
1

I have to develop a method for water content by KF for Pregabalin. Please let me know the quantity of the sample to be used to determine the water content. Explain the process of setting that limit, so that i can use it for other in-house Drug substances.

Thanks in advance.

Regards
N.Srikanth

2

as per usp 921

select weight of the test sample such that 10% of the burette volume should be consumed.

The amount of Expected MC Should be considered.

Analyse ten replicate preparations and establish the uncertainity or establish the precision.

If the MC is below 1%. prefer to use KF Reagent 2 mg/ ml rather than 6 mg/ml.

Regards,
Bujji Reddy kanchi.