Chromatography Forum

hello friends
please,if I test 10 coated tablets individually,can I report the average of this 10 dates as a assay result?

Is well done,to do this ?

Thanks for your post

Paul

Yes, you could test separately 10 tablets and obtain 10 results from their assay determination, and express the assay for e.g API like a mean value of 10 measured individual values.

What does your assay procedure say? Firstly you should look there.

Best regards

thanks,zoktano.
My procedure is from USP,For coated tabets of Ibuprofen.
This procedure say that I must to bring a number of tablets in a volumetric bottle to make a concentration of 12 mg/mL, but this is is so dificcult,if i have tablets of 800 mg of ibuprofen...

Please,your suggest is so valious to me...but,where can I get information about this way to make the assay (one tablet by ten)...is acepted in the world or why not is employed frecuently,or what statistycal considerations have this procedure...

Many Thanks
Paul

Paul,

USP assay procedure for Ibuprofen coated tablets states that, as you said, the final sample solution should be 12mg/mL with respect to ibuprofen. It also states that whole coated tablets equivalent to not less than 1200 mg should be added in to a volumetric flask in order to make 12 mg/mL sample solution.

So, if the declared content of ibuprofen in the coated tablets is 800 mg, you could place 3 tablets (3x800mg = 2400mg) in to a 200 mL volumetric flask. Then add sufficient volume of internal standard solution (as is in the procedure) to make up to 200mL. Disintegrate the tablets by shaking them with glass beads. The final concentration of ibuprofen will be round 12mg/mL (2400mg / 200mL = 12 mg/mL).

Or, in the same way, you could place, for instance, 15 coated tablets (15x800mg = 12000mg) in to a volumetric flask of 1000mL. The final concentration of the ibuprofen again will be round 12 mg/mL.

Hope this helps

dear Zokitano.

First,thank you

the question is that in my lab,the minimal quantity of tablets that can it takes to prepare a sample is five...the option of take fifteen in 1000mL,is good,but my procedures say that I must take to prepare three samples,i.e
three volumetric flask of 1000 mL...so,a lot of acetonitrile...and it is so expensive to me.

My question is right now,how can i get to simplify the general procedures...where can I get some information about the minimal quantity of tablets that I must take to prepare a sample one...this is for to present to my boss a consistent answer.
Thanks again

Paul duque from Colombia,South America

Hi Paul

There is no such thing: â€

I agree with Danko. When one runs uniformity of content it is more convenient to do single 10 measurements (assays) of 10 separate dosage units (e.g. tablets) in to 10 separate sample solutions.

But when you're running assays and they are stated in the Pharmacopoeia than you should stick to the procedures described there. Unless it is otherwise stated, you can use different whole number of tablets in your assay (3 or 15). Because in this case USP doesn't states precisely how many tablets should be dissolved in the determined volume of solution. Instead, it gives the concentration of the final sample solution that one should obtain/prepare.

Best regards

I would consider taking 15 tablets to 1litre with 0.01M NaOH and doing without an internal std.

thank you friends.

Now ,i have many professional ideas....tanks again

Paul