Work with Ointments and creams in UPLC

DoriGarcia

<p><span>Have you ever worked with ointments and creams in UPLC? Although I would filter the samples with a 0.22 filter, I am afraid of the fact that fats of the ointments, which are impossible to filter completly, could block the inline filter or the column. Have you ever had this problem or you run ointment samples in UPLC routinly without problems?</span></p><p></p><p><span>Thank you very much</span></p><p></p><p><span>Dori</span></p>

lizh

We have successfully analyzed creams and ointments, but for example is your compound of interest likely to be more soluble in the fat? Dilute and filter can be OK, but we do not know what you are looking for so we need some additional information before making good recommendations. However, I would recommend a guard column rather than an inline filter in this case. Can you send the present HPLC and UPLC method and sample prep methods.

Best regards,

Liz

lizh

Here is one example I remembered in an older UPLC application.

Liz

Edited by: Elizabeth Hodgdon on Mar 11, 2009

Outback

Hi Dori,

I have found a good way to deal with creams is to dissolve ~ 1 gm cream with 80 ml methanol, you may need to heat it up to get a clear solution. Once it clears put it in the refrigerator to cool, on cooling most of the lipids drop out and the sample can be made up to volume and filtered. If the sample doesn't clear with heating you may need to add a little THF before cooling.

The important point is unless you start with a relatively clear solution there is a good change some of your active may be encapsulated in the fat emulsion.

Best of luck!