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Vecuronium Bromide impurity method

Posted: Tue Oct 09, 2012 1:59 pm
by tubish81
Hello

Do you have any impurity method HPLC-UV for vecuronium bromide.
There is a method at EP, but using column is short life.
Can you help me ,please?


Thank you

Re: Vecuronium Bromide impurity method

Posted: Tue Oct 09, 2012 7:11 pm
by Vlad Orlovsky
Do you have details of your methods available: column type, mobile phase composition and detection technique? I might be able to suggest something better than you have right now.

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 5:46 am
by tubish81
Chromatographic Conditions:
Column
Supplier : Zorbax
Type : Bonus RP
Optimum size : 5 micron
Length : 250mm
Diameter : 4.6mm
Flow rate : 1.2 ml/min
Detection : UV-210 nm
Injection volume : 10µL
Column temperature: 40C

Preparation of Solutions
Mobile Phase : Transfer 18 g tetramethylammonium hydroxide pentahydrate R into a 1 L beaker and add 1000 mL of water and adjust with phosphoric acid to a pH 6.5. Mix 90 mL of this solution, 250 mL of methanol and 660 mL of acetonitrile.

pH value is very high, but when we reduce this value and concentration ion pair reagent, we can't separete impurities.
We tried column too much.
Actually,vecuronium is bases compound,so theoretical we can use sodium alkanesulfonate as ion pair reagent. But chemistry is mystery :) We have nothing.


Thank you for your concern

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 6:47 am
by prepcolumn
did you change your idea of purchasing MS-MS?:)

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 7:29 am
by tubish81
:D We'll purchase as soon as.But we haven't LC/MS-MS now.

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 7:39 am
by prepcolumn
Tubish

The reason of anionic ion pair reagent is not the vecuronium itself but the hydrolysis impurities (i mean your degradation products are zwitter ionic).
I think Vlad can suggest you good Sielc mixed mode or hilic columns.

Let me know if you need MS-MS application :wink:

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 7:57 am
by tubish81
:roll: Thank you
We tried Merck Hilic column at same conditions. We can't obtained USP imp C and imp F.
:cry: :cry: :cry: :cry: :cry:

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 8:03 am
by prepcolumn
:roll: Thank you
We tried Merck Hilic column at same conditions. We can't obtained USP imp C and imp F.
:cry: :cry: :cry: :cry: :cry:
What do you mean with same conditions? Did you use ion pair agents with hilic column?

Re: Vecuronium Bromide impurity method

Posted: Wed Oct 10, 2012 8:42 am
by tubish81
Sorry for this information. :D We didn't use any ion pair reagent with hilic column.
The conditions used are as follows.

Supplier : Merck
Type : ZIC-HILIC
Optimum size : 5 micron
Length : 250mm
Diameter : 4.6mm
Flow rate : 1.0 ml/min
Detection : UV-210 nm
Injection volume : 5 µL
Column temperature: 30C

Mobile Phase : 0.015 M amonnium acetate buffer (pH 5.5with acetic acid):Acetonitrile (20:80)