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Hello everyone:
I am doing my PhD in Pharmacie Clinique at the Universit=E9 Laval in
Qu=E9bec. Recently, I have been trying to develop an assay for the
analysis of enatiomers of metoprolol in biological samples using the
Chirex cloumn from the company Phenomenex. As suggested by the company
I am presently using Hexane:DCE:ETOH-TFA (60:35:5) for the mobile phase
where ETOH-TFA is 20-1. I am getting seperation for the peaks for R and
S enantiomers but the peaks are quite broad and tail also, and despite
the number of changes in the mobile phase I tried, I have not succeded
in making the peaks sharper. I was wondering if anyone has had any
experience in using the Chirex column for a similar separtion of a
beta-blocker or amines etc and could suggest me something in this
regard.
Thanking you
yours sincerely
Ashish
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=C2shish Sharma (B. Pharm., M. Sc. Pharm (Pharmaceutics), D.P.M.P.)
Center de Recherche en cardiologie
H=F4pital Laval
2725 Chemin Ste-Foy
Ste Foy
Qu=E9bec G1V 4G5
Canada
Num=E9ro de T=E9lephone: 656-8711 (poste:5448)
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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[Two replies - db]
From: "Sasso, Patrick [PRI]"
To: "'PharmPK.-a-.pharm.cpb.uokhsc.edu'"
Subject: RE: PharmPK Chiral separation
Date: Tue, 2 Feb 1999 08:41:12 -0500
MIME-Version: 1.0
Is this a bi-tartrate, and could that effect pH of the sample slug?
---
Date: Tue, 2 Feb 1999 09:54:38 -0800 (PST)
From: yang sai
Subject: Re: PharmPK Chiral separation
To: PharmPK.-at-.pharm.cpb.uokhsc.edu
MIME-Version: 1.0
Hi, Ashish,
If you this column, Chirex column, I suggest you should change the
mobile phase you used. You can use propanol instead of ethanol.
Yang
==
Yang Sai
12012 10th Place NE
#E106, Seattle, WA 98125
Tel: 206-364 8427(H); 206-685 1869(O)
Fax: 206-685 3079
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Dear Dr. Ashish,
The column you use is a really bad choice for separating b-blockers. The
best choice in case of plasma sample is to use Chiral AGP, and the
second
best choise is the column Chiral CBH. At this pasge from the Swedish
Company
Chromtech AB you can see the chromatograms of the two columns separating
R
and S metoprolol. http://www.chromtech.se/meto-2x.htm.
I recommend strongly you to buy Chiral AGP. Many bioanalysis
publications
deals with the separation of R and S metoprolol with Chiral AGP, see the
homepage
http://www.chromtech.se/abc.htm.
I talked with Inger Hermansson in this company about your problem, and
she
said you are wellcome with questions to her. You find email adresses on
http://www.chromtech.se.
My Best Wishes
Torgny Fornstedt
associate prof. in Analytical Chemistry in the Department of
Pharmacokinetics
Pharmacodynamics in Uppsala Sweden.
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Would that column allow resolution of a parent and a metabolite with R/S
compounds as well or must it be optimized for each pair.
Date: Sun, 21 Feb 1999 08:52:11 -0500
From: "Edward F. O'Connor"
X-Accept-Language: en
MIME-Version: 1.0
To: PharmPK.at.pharm.cpb.uokhsc.edu
Subject: Re: PharmPK Chiral separation
is the resolution accepatble? Is the asymmetry > 1.2? are there
restricitions on the asymmetry? 1. Increase temperature in increments of
10 C to 60 C (usually the limit. 2. Try TEA, 3. decrease pH > 3.0. 4.
change hardware ( reduce ID and length.
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Hello there:
The resolution is indeed good and so is the asymmetry. TEA did not work
well at all...I also tried N,N-dimethyl dioctyl amine (I got no chiral
separation with that and the peaks became broader). Our pH is indeed
greater than 3. Temperature seems to have helped us a bit now. The
peaks seem to have improved quite a bit actually with the change in the
temperature and by reducing the flow. I have been playing around with
the hardware as well! I am right now only working on Metoprolol
seperation (no metabolites at this time).
yours sincerely
Ashish
Centre de Recherche de l Hopital Laval
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Hi Ashish
I am not sure if you have read our paper on the direct chiral separation of
metoprolol but certainly we have been using this method successfully now
for several years in our pharmacokinetic studies. Here is the citation for
you:
Doroudian A, Yeleswaram K, Rurak DW, Abbott FS, Axelson JE. Sensitive
high performance liquid chromatographic method for direct separation of
labetalol stereoisomers in biological fluids using an alpha1-acid
glycoprotein stationary phase. Journal of Chromatography 619(1):79-86, 1993.
I hope this will be of some assitance to you.
Sincerly
Wayne
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Copyright 1995-2010 David W. A. Bourne (david@boomer.org)