Stationary Phase for Sodium Alendronate EP Method

[cristobal]

I wonder if any of you have compiled a list of comercial alternatives for Europen Pharmacopoeia stationary phase Anion exchange resin R1(1123400).
Our AD lab have to compare the results obtained with our "in house" HPLC methods for inorganic impurities and assay with the corresponding monograph methods (SODIUM ALENDRONATE-01/2008 :1564-corrected 6.3).
The monograph indicates that a Column l = 0.15 m, diam. = 4.6 mm filled with Anion exchange resin R1 (7 um) (Anion exchange resin R1. 1123400.: Resin containing quaternary ammonium groups [CH2N+(CH3)3] attached to a lattice consisting of methacrylate)have to be used for the assay and purity analysis of alendronate sodium.
The column indicated in the Pheur Knowledge Database is Allsep Anion Column: l = 0.15 m, diam. = 4.6 mm 7 µm from Alltech (Now merged into Grace Davison - Discovery Sciences).
We were having troubles obtaining that column as distributors informed that both Columns Part number AT 51208 (SS body) and AT 51209 (PEEK body) are out of stock and are going to be discontinued.
We contacted directly Grace Davison - Discovery Sciences.
Its Technical Support Manager Susan Diaz (Susan.Diaz@grace.com) informed us that:
QUOTE "I am sorry but both the Allsep column and Allsep A-2 column are either discontinued or in the process of being discontinued.
We do not have anything that would be an equivalent.I am sorry but we no longer have a column that meets the specifications that you have listed below."UNQUOTE

I can't find any packing that would be an equivalent to Anion exchange resin R1 (7 um).

Can anybody help finding an equivalent alternative?

Many Thanks!

[Vlad Orlovsky]

here is article on similar compound:
Direct stability-indicating method development and validation for analysis of etidronate disodium using a mixed-mode column and charged aerosol detector Liu, X.K., Fang, J.B., Cauchon, N., Zhou, P.,
Journal of Pharmaceutical and Biomedical Analysis, Vol. 46, No. 4, pages 639-644 (2008)
1/2008

The method uses our Primesep SB column. It is reversed-phase anion-exchange column.
Here is method for separation of "dronic" acids including alendronic acid:
http://www.sielc.com/compound_248.html

[krickos]

Hi

If this column type (eqvivalent enough) really is not possible to get your hands on, have you considered using the USP monograph as an alternative?

The USP monograph calls for a L21 packing ( A rigid, spherical styrene-divinylbenzene copolymer, 5 - 10 µm in diameter ).

[Bruce Hamilton]

I'd go back to the EP, and ask about their approved alternative. If they haven't got one, they should be working urgently on defining one.

I'd also go on a worldwide search for any of the Allsep Anion columns sitting on distributors' shelves, or ask Discovery Sciences to do that on your behalf..

Good luck,

Bruce Hamilton

[Willy]

Hello Cristobal,

We have found one that could be equivalent to the column posted in EP. Its an Hamilton PRP-X500 anion exchange column. We are trying it as i speak and will see if it works well.....


Willy the GC

[danko]

Hi Guys,

Isn’t that typical: The column isn’t in production anymore and even though it’s possible to find another column that might be able to do the job (anyway after some adjustments) one is not aware of the exact goal. The problem arises from the fact that pharmacopoeias (or the folks that administer them) don’t want to publish chromatograms. You may be guided to some extend by other information, such as retention times for selected peaks etc. But there is so much more to chromatography and nobody publishes all other metadata (e.g. plate count or peak capacity and other useful information) that could indicate a viable method match.
I’ve discussed the issue, with a pharmacopoeia expert, once and the message was: We usually don’t do that.
I think one of the problems that hassles chromatographers trying to implement a pharmacopoeia method is exactly the lack of graphic data.

Another thing is the quality of some of the methods, but that’s a different discussion.

Best Regards

[grzesiek]

danko, I agree with you 100%, validation data should be available for anyone interested in my opinion

cristobal, I would do as Bruce Hamilton suggested, get in touch with EP experts

[krickos]

. The problem arises from the fact that pharmacopoeias (or the folks that administer them) don’t want to publish chromatograms.

Hi Danko

I agree, at least partly. For new monographs in Ph Eur (or new purity methods) chromatograms are usually acessible through the database (no subscription required):
http://extranet.pheur.org/publications/ ... s_sw.shtml

On the other hand, why have not Ph Eur published chromatograms for older monographs? I mean they do sit on the data why not upload those as well and make life/work a bit simplier or at least more informative?