Back to the Top
1-How to carryout extraction of water soluble drug in plasma with good
recovery if the drug having both acidic and basic ionization group. How
to adjust the pH so could get good recovery in plasma?.
2-how to reduce the esterase enzyme activity of plasma?
I will be very pleased if I get the answer of this question.
Back to the Top
The following message was posted to: PharmPK
Dear Mishra,
ad 1) you could a mixture of a water unsoluble organic solvent (to
precipitate the plasma) and water phase with a alteration in pH (e.g. 2
or
10) at which the compound should be ionized. Analyze the water phase
ad 2) pefabloc is a good esterase inhibitor, we use it at 25mM, though
(check for physical interaction of your analyte)
best regards,
Philip
Philip Lienau
Schering AG
Research Pharmacokinetics
Tel.: +49 - 30 - 468 - 18507
Fax: +49 - 30 - 468 - 12238
Back to the Top
The following message was posted to: PharmPK
Dear Mishra,
In addition to the suggestions by Philip.Lienau:
When the analysis in precipitated plasma is still not sensitive enough,
try
the following:
1) extraction with organic solvent (like ethyl acetate) or RP SPE
columns
after pH correction to the isoelectric point of the compound (mostly
about
pH 4 - 8)
2) use an ion exchange column in SPE (cation or anion) or a combination
columns
3) use an LC with on-line extraction
succes !
Ben de Rooij
PharmPK Discussion List Archive Index page
Copyright 1995-2010 David W. A. Bourne (david@boomer.org)