Does someone have an idea to improve the recovery?

[Wujustrair]

Hello everyone,
this is my first topic here and I hope that you can help me.
I'm developing a new method to determine octenidine dihydrochloride in gel formulation with Carbopol 971P and I'm having a lot of problems to recovery all the content of this active ingredient.
Does someone have an idea to improve the recovery?
I'm diluting samples in citrate buffer at pH 2.8 (mobile phase of the method) and filtering them with RC 0,45um. Note: if I don't filter the sample, the recovery is about 100%!!! But I can't do that in the analysis routine because I will collapse the column quickly.

Thank you very much in advance!!!

[Neon]

If you suspect that the problem lies in the filtration, you can try the following:
a) change the type of filter or at least test filters from different manufacturers,
b) try centrifugation instead of filtration,
c) do not collect the first or last drops of the filtrate; try to collect the middle fraction.

[bevis0405]

It’s great that you're developing a method for octenidine dihydrochloride — it’s a tricky compound, especially in Carbopol gels. Paper io

[johnnysmith]

Interesting issue! Since unfiltered samples show 100% recovery but filtered ones don't, the problem likely lies with the RC 0.45µm filter adsorbing your active ingredient. Here are two quick suggestions:

1. Try alternative filter materials - PVDF or nylon filters often have less adsorption than RC membranes
2. Pre-wet the filter with a small amount of your sample solution before collecting the filtrate for analysis

You might also want to check if sonicating the sample briefly before filtration helps. Keep us posted on what works!

[jamil]

Hello everyone,
this is my first topic here and I hope that you can help me.
I'm developing a new method to determine octenidine dihydrochloride in gel formulation with Carbopol 971P and I'm having a lot of problems to recovery all the content of this active ingredient.
Does someone have an idea to improve the recovery?
I'm diluting samples in citrate buffer at pH 2.8 (mobile phase of the method) and filtering them with RC 0,45um. Note: if I don't filter the sample, the recovery is about 100%!!! But I can't do that in the analysis routine because I will collapse the column quickly.
miside
wacky flip
Thank you very much in advance!!!

Very interesting challenge! The 100% recovery without filtration clearly points to the filter adsorption issue.
Excited to hear what solutions emerge ! Looking forward to seeing how this method develops.

[pigkang]

Hello everyone,
this is my first topic here and I hope that you can help me.
I'm developing a new method to determine octenidine dihydrochloride in gel formulation with Carbopol 971P and I'm having a lot of problems to recovery all the content of this active ingredient.
Does someone have an idea to improve the recovery?
I'm diluting samples in citrate buffer at pH 2.8 (mobile phase of the method) and filtering them with RC 0,45um. Note: if I don't filter the sample, the recovery is about 100%!!! But I can't do that in the analysis routine because I will collapse the column quickly.
Thank you very much in advance!!!

This is my first topic here, and I truly appreciate any advice or insights you may have.

I’m currently developing an HPLC method to determine octenidine dihydrochloride in a gel formulation using Carbopol 971P. However, I’ve encountered a significant challenge with recovery rates. I’m having trouble recovering the full content of this active ingredient, and it’s impacting the accuracy of my results.

Here's what I'm doing so far:

Sample dilution: I'm diluting the gel samples in citrate buffer at pH 2.8, which also serves as the mobile phase.

Filtration: I’m filtering the samples through a regenerated cellulose (RC) 0.45 µm membrane filter before injection.

[pigkang]

Hello everyone,
this is my first topic here and I hope that you can help me.
I'm developing a new method to determine octenidine dihydrochloride in gel formulation with Carbopol 971P and I'm having a lot of problems to recovery all the content of this active ingredient.
Does someone have an idea to improve the recovery?
I'm diluting samples in citrate buffer at pH 2.8 (mobile phase of the method) and filtering them with RC 0,45um. Note: if I don't filter the sample, the recovery is about 100%!!! But I can't do that in the analysis routine because I will collapse the column quickly.
geometry dash
Thank you very much in advance!!!

Very interesting challenge! The 100% recovery without filtration clearly points to the filter adsorption issue.
Excited to hear what solutions emerge ! Looking forward to seeing how this method develops.

If I skip the filtration step, I get almost 100% recovery, which confirms the method’s potential.

However, I must filter to protect the HPLC column and maintain routine analysis, and that’s where the significant loss in recovery occurs.

[Piere1999]

Hello everyone,
this is my first topic here and I hope that you can help me.
I'm developing a new method to determine octenidine dihydrochloride in gel formulation with Carbopol 971P and I'm having a lot of problems to recovery all the content of this active ingredient.
Does someone have an idea to improve the recovery?
I'm diluting samples in citrate buffer at pH 2.8 (mobile phase of the method) and filtering them with RC 0,45um. Note: if I don't filter the sample, the recovery is about 100%!!! But I can't do that in the analysis routine because I will collapse the column quickly.

Thank you very much in advance!!!

It sounds like the octenidine is binding to the filter. You could try using a different filter material, like PVDF or PTFE, which might reduce adsorption. Also, pre-rinsing the filter with the mobile phase can sometimes help improve recovery. Good luck!