Method Validation - different tablet strengths

[michaelcarolus]

Hi All

I'm busy with a method validation for 3 products each containg 0.25, 0.5 and 1 mg/tab of API. The excipients are identical in all 3 products except that the dye's are different in the products. The working concentration of the assay for all 3 products are the same i.e 0.025mg/ml. Could I combine the 3 products and run one validation for all 3? I was thinking of validating the higher strength (1mg/tab) and using the data for all 3 strengths . As an additional test I was wondering if I should do method precision for the the other 2 strengths as well.

Any comments/suggestions would be appreciated.
Thanks
Mike

[Consumer Products Guy]

If it was me:
Yes, I'd ABSOLUTELY do one validation, and tailor my test procedure so I would just use correspondingly smaller amounts of sample for the two higher level products, everything else the same. So one test method, maybe "weigh sample to xxxx", with Note such as:
NOTE:
use 0.9-1.1 gram sample for levels expected to be 0.25
use 0.45-0.55 gram sample for levels expected to be 0.50
use 0.20-0.30 gram sample for levels expected to be 1.00

Anyway, if you were validating "one", I'd choose the lower level. But I'd combine as one test procedure, so one validation. Dye level is very low.

[syx]

we run one validation, but the specificity should be done separately since they may have different excipients.

[Dan]

I agree with the others in that you can and should simplify your validation.

Since you have only the one working concentration, then you would have only one linearity, LOD and LOQ.

You can also consider bracketing: using just the high and low strengths for some validation experiments. That would be acceptable for solution stability, accuracy and precision.

As Syx noted, test specificity for each strength.

Regards,
Dan

[michaelcarolus]

Morning All

Thanks for the comments thus far. I will definitely combine all 3 validations into 1.

thanks again
Mike

[krickos]

Hi

I agree with the others but would like to add that you might need to consider all strenghts when it comes to the Robustness part (stability of solutions).
As I understand it you dissolve different amount of tablets in a given amount of solvent to obtain the same concentrations, hence the concentration of excipitients, dyes etc will vary between the strenghts and just may have impact on the stability of solutions.