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I am analyzing the rate of biliary excretion of amiodarone in rats and
trying to develop
a analytical procedure for extraction of drug from bile. Presently I am
using Oasis HLB cartridges and eluting with 70% ethyl acetate and 30%
methanol and there is lot of interference (in UV detection) from the
bile salts. Is there a way that I can precipiate bile salts before
I will appreciate any suggestion regarding solid or liquid phase
Massachusetts College of Pharmacy. Boston
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Amiodarone acts as a hydrotrope, and so self-associates in the presence
of water. In the presence of surfactants, such as bile salts, it forms
extended micelles, (which may be rod- or worm-like, by analogy to other
Perhaps you can substitute another hydtrotrope which is more similar to
Amiodarone than the bile salts are, in order to break-up the micelles.
The result will still involve extended molecular associations in water.
Frank Bales, Ph.D.
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i did some liquid-liquid extraction a few years ago. i acidified the
bile with acetic acid till the pH was brought down to 2. in that
process the salts normally reacted with the acid and dissolved, then i
basified the sample (as my drug was a weak base) and extracted with an
organic solvent. to remove the interference i back extracted the dry
extract with hexane to remove some of the interfering impurities.
[before extracting with hexane you have to acidify or basify depending on
the nature of ur molecule if the drug is weakly basic you have to acidify
other wise basify if weakly acidic in nature. also you have to confirm if
u dont loose ur drug in the washing.the idea is that the desired entity
would be ionized and should not extract with nonpolar solvent while
taking away quite a bit of junk with it] after washing with hexane
again basify or acidify (depending on the pka of ur molecule) and
extract with desired solvent. you should be able to get very clean
samples. For me this technique
worked like a charm.
hope this works for u.
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