Comparative dissolution of Levothyroxine tablet

[phucto]

Any one help me the method to test comparative dissolution of Levothyroxine tablet according to USP

[HPLCaddict]

Any one help me the method to test comparative dissolution of Levothyroxine tablet according to USP

What exactly do you need? The USP method for dissolution testing of Levothyroxine tablets or a setup for a comparative dissolution testing of two different brands of these tablets?

[phucto]

Thank you for your reply. I am perform comparative dissolution of my Levothyroxine tablet using USP dissolution method 1. The samples were taken at time 5,, 10, 15, 30, 45 minutes. I am meeting a problems with separation: I tried to change many HPLC column C18 (include new purchased column) and rum in two different HPLC system, change the mobile phase ratio (the mobile phase include of water: methanol and phosphoric acid (40:60: 0.1) but the separation was very bad. Because the labeled amount of the Levothyroxine tablet is low (0.1mg/tablet) and low solubility of this tablet. So when analyzing of sample taken at 5 minutes, we got low detection of peak of levothyroxin. Any one give me some idea or share me some experience in perform comparative dissolution of this tablet. Thank you very much.

[HPLCaddict]

What do you mean by "separation was very bad"? What exactly is the problem with the chromatography? Separation itself or is just the peak of the early time points too small?

I just had a look at the USP method - Woha!! 800µL injection volume? Did you use this?
If you've got in fact chromatographic problems, did you use the exact column mentioned in the USP (µBondapak)?

Did you use the exact USP procedure (500mL medium, 0.2% SDS)?. If you've got too low peak areas for the early time points, it sounds as if the solution rate of the API is very slow. This would mean, it's not problems with the method you're seeing, the tablets are really dissolving that slowly so you don't see very much after 5 minutes. There must be a a reason why specification is after 45 minutes...
Why not omit the 5 minutes time point and start collecting at 10 minutes? The EMEA guideline on dissolution profile comparison states a minimum of 3 time-points, so 10, 15, 30, 45 minutes would be fine...

[angi]

yes, HPLCaddict has right.
and if your percentage dissolved in 15 min is more then 85 % then the f2 has little relevance.
With this dissolution profile you make product development (with bio - batch ) or only comparative dissolution profiles?
cheers!