Chromatography Forum

I have a TLC method that I am going to use as a second ID method for a drug product. Does anyone have a good reference for "validation" of a TLC ID method?

I'm assuming that the main parameter is specificity, but what do I show specificity from?

Thanks

Hi BenNC

I have no guidelines, I can tell you only how TLC validation has been performed by myself:

- Prepare the following solutions:
- sample solution
- standard solution
- placebo solution
- placebo/standard solution

- Perform TLC under the following conditions:
- correct solvent / saturated chamber
- correct solvent / unsaturated chamber
- solvent variation 1 / saturated chamber
- solvent variation 1 / unsaturated chamber
- solvent cariation 2 / saturated chamber
- solvent variation 2 / unsaturated chamber
- and so on

Analyte spot must be visible everywhere excepted the placebo solutions. The Rf value of the analyte has to be the same for each of the other three solutions (= Specificity), but Rf values have NOT to be the same when comparing different TLCs.
When Specificity is fulfilled in all experiments, method is robust.

Regards
Florian

Determination of LOD is also required apart from the parametrs already mentioned earlier. you can verify the spot purity by TLC scaner ( if you have one )and check the UV scan of the spot.

good luck

Ben
you might want to check this useful paper. It gives practical approaches for validation in thin layer chromatography.

Ferenczi-Fodor et al.: "Validation and Quality Assurance of Planar Chromatographic Procedures in Pharmaceutical Analysis".
Journal of AOAC International Vol. 84, No. 4, 2001, p. 1265-1276

Regards

Thanks for the responses