Chromatography Forum

HI FRIENDS,

LOOKING FOR HPLC METHOD FOR IBANDRONATE SODIUM

I was not familiar with this compound but a quick search gave the structure at http://www.uspharmacist.com/index.asp?p ... efault.htm

A quite interesting amphiphilic one.

I am quite sure that a bonded HILIC column, like our ZIC®-HILIC or the polymeric ZIC®-pHILIC columns are suitable for this problem since the hydrophilic part of the molecule is the most significant.

Ibandronate is one of a dozen or so bisphosphonate drugs. They are all strongly acidic, hydrophilic, chelating agents. Mostly they have poor UV chromophores. There have been several threads in the forum on related drugs (etidronate, alendronate, pamidronate, etc.). A lot of frustrated chemists out there...

What kind of metals will these bisphosphonates chealate? One method for analysing amino acids is ligand exchange chromatography. Copper II is added to the mobile phase and forms a d-electron complex with amino acids that is uv-active. Mainly I'm floating this idea as a detection scheme here, but it could also be used to address separation/retention.

They are structurally analogous to pyrophosphate with a carbon bridge instead of oxygen to make them resistant to hydrolysis. Their physiological activity comes from calcium binding, especially on bone. Pyrophosphate is an excellent chelator for ferric iron with a characteristic purple color, and I expect these are similar.

I think they would be good candidates for ion chromatography with conductivity detection. My official domain is reversed-phase applications, so I'll need to find someone else at Dionex willing to take it on.

Before you try or even think about ligand exchange chromatography I strongly recommend that the straightforward HILIC technique is considered.

I have worked with alendronate. I used refractive index detector and anion exchange column. It works well.

I have worked with risedronate (this species of bisphosphonates has uv-chromophore) using TBA and reverse phase column with low metal impurity of silica.