Sample containing HPMC 4M

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

5 posts Page 1 of 1
Hello,

I'm trying to extract analyte from tablets containing a high viscous HPMC polymer without crushing tablets and without shaking for long periods of time. Ideally I would like to simply add tablets to a flask, add a solvent, shake, dilute, and filter.

I have a couple techniques I've tried but it always seems hit or miss. I've tried adding a solution of 10% Acetic Acid in water:Methanol (90:10) and heating at 60C - 90C for 15minutes - an hour to disintegrate the tablets. Sometimes this works and the tablets fully disintegrate and sometimes they gel and I get low recovery.

Is there any osmotic techniques that I could utilized once the tablets are swelled to quickly extract analyte?

Thanks
Try extracting with a stronger acid like Phosphoric Acid.
Have you looked into using a mechanical shaker that is inside of a water bath? This may provide enough motion that the tablets have less of a chance to gel while they dissolve in a higher temperature.

Another option could be placing the flasks into a sonication bath as that may be sufficient to dissolve the tablets, and in many cases they can have their temperature set as well.

When I have analyzed whole tablets in the past - if they were solid tablets - I would at least try to cut them in half with a razor blade and then I just shake for an hour at room temp or shaking inside a heated water bath. Cutting them helps expose the inner tablet, and increases overall surface area to help promote disintegration.
I'm trying a 0.2M Perchloric Acid Solution now. Adding 10mL to a 50mL v.f. with 1 tablet and sonicating. Then ideally, I will dilute to volume with some sort of buffer to bring the pH back in line with my mobile phase.

So far this doesn't seem to be working the best.

We don't have any mechanical shakers in water bath here and my management would most not likely buy any for a single application as we are limited on space and resources. So I'm working with the best I have.

The tablet cutting doesn't seem like a bad idea, however, this will eventually go to QC and they will be running a TON of Content uniformity samples. Not sure how they would feel about cutting tablets.

Any other ideas welcome :)
Geof235 wrote:
I'm trying a 0.2M Perchloric Acid Solution now. Adding 10mL to a 50mL v.f. with 1 tablet and sonicating. Then ideally, I will dilute to volume with some sort of buffer to bring the pH back in line with my mobile phase.

So far this doesn't seem to be working the best.

We don't have any mechanical shakers in water bath here and my management would most not likely buy any for a single application as we are limited on space and resources. So I'm working with the best I have.

The tablet cutting doesn't seem like a bad idea, however, this will eventually go to QC and they will be running a TON of Content uniformity samples. Not sure how they would feel about cutting tablets.

Any other ideas welcome :)


Without giving away too much information that you may or may not be able to provide...what are the excipients of the tablet? Aside from HPMC, which you have stated, is there any other plaster or binding agents the tablet is made out of? This information might help in finding a suitable solvent to promote disintegration/dissolution.

While the tablet cutting may or may not be a nightmare for the QC side, especially with high volume, it may be worth testing on your end anyway to see if increasing the tablet surface area is providing better disintegration and better results, and then possibly work backwards from there.
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