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Hello everyone:
I am doing as research scientist in apotex india LTD . Recently, I
have been trying to developing an bio-analytical assay for the
analysis of betahistine in biological samples by lc-ms/ms (API-4000)
using the Discovery cyno column 50 x 4.6mm cloumn from the company
Supelco and mobile phase was 5mm Ammonium acetae pH-5.0 adjusted with
glecial acetic acid : ACN ; 50:50(isocratic).I am presently trying
solid phase extraction using MCX ,MAX and HLB (waters catridges
manfacturing) for better recovery . In this process canditoned with
MEOH,water, sample loaded 0.5ml , washed with 2ml of water,2ml of 2%
formic acid and elution with 4% NH4OH in Methanol (MEOH). Evoparated
the sample at 50 C temparature under pure nitrogen gas up to 40min
and reconsuted with 5mm Ammonium acetae pH-5.0 adjusted with glacial
acetic acid : ACN ; 10:90(isocratic). I am getting analyte and IS
(betahistine derivative) peak response more in blank human plasma
(K2EDTA) I tried, I have not succeeded in removal of peaks in blank
plasma and making the peaks sharper. I was wondering if anyone has
had any
experience in using this betahistine and could suggest me something
in this
Regards.
Thanking you
yours sincerely
suresh
VenkataSuresh.Ponnuru
Apotex research private ltd
ARPL\BEC\BL
Rsearch Scientist
4th phase,jigani link road,
Banglore-560099
Office:- 080-22891000
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The following message was posted to: PharmPK
Hi,
Are you sure the peaks in blank are not from carry
over?
Xiaodong Shen
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The following message was posted to: PharmPK
Hi,
Betahistine is a base and FW is only 136 and it is
quite polar. I would try strong cation exchage
cartridge, but not max, or HLB. Since the molecular is
so small, I guess the peaks from blank are
interference peaks from endougenous components.
Maybe is is not a bad idea to try hard during washing
steps when using SCX, or MCX.
It is a tough one, and good luck.
Xiaodong Shen
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Dear Dr .suresh
Did you tried LLE method for extraction of betahistine. LLE is the
best method for the extraction of most of the drugs and also economical.
I would like to sugest that
1.Try LLE and protein precipitation methods
2.Find out the maximum recovery of this 3 methods
3.Try to use the reconstitution solvent same as to that of MP.
4.Then you could try for inj fort washing or needle wash step
5.However the best option is change the extraction method .
I hope this would helps for you.
Thanks
A.karthik
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Dear karthik
we i tried on LLE and Protein precipitation also still getting
interference in blank and less recovery so please suggest me about
this method how to trrouble shoot and get maximum recovery from
plasma samples
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