Chromatography Forum

Hi!

I was just wondering if there exist any method which may determine assay of both compounds (clindamycin phosphate and bezoyl peroxide) at once. The problem is that clindamycin is rather polar compound while benzoyl peroxide is nonpolar at all.

The problem starts with finding a common solvent for both compounds.

Did anyone face such problem?


P.S. Sorry for my english - it is not my mother tong

Mixed-mode is your answer. Your antibiotic will retain by weak reversed-phase and strong cation-exchange, and peroxide will retain by reversed-phase mechanism. Something like these:
http://www.sielc.com/Application-Comple ... ounds.html
http://www.sielc.com/Application-HPLC-S ... lumns.html

One of potential problems is reactivity of benzoyl peroxide.

contact me if you have questions

Found both compounds in the lab. We will try to develop method for you.

Regards,

I will be very thankful if you try to develop this method.
I have already done some runs but results are unsatisfaing. I have tried C8, C18 and hypercarb columns with diffrent phases like potassium phosphate buffer pH = 2,5 - 3, ammonium acetate buffer pH = 5,2 etc.
The best result so far was obtained for hypercarb column and ammonium acetate bufer with pH = 5,2 but resolution between peaks of clindamycin phosphate and benzoyl peroxide was too low.

We have an old mixed-mode column and i would have liked to try that one but it was occupied by my colleague. Now i will persuade him that i seriously need it

I have a method for you. Please send me your email through our website:
http://www.sielc.com/AboutUs_ContactUs.html

In our application they are about 2 minutes apart (resolution is about 9) but you can increase it to 4-10 minutes depending on conditions.

Kind regards,

Vlad

I sent you my email through your company website.

hi Vlad,
is it possible to get the method from you once again?

Here is application for separation of clindamycin and benzoyl peroxide. You will need to use two detection techniques as clindamycin has very limited UV:


Clindamycin is retained by combination of weak RP and strong cation-exchange, BP is retained by pure RP mechanism. You can change order of elution for compounds by changing mobile phase composition.
contact me if you have questions.

This could also be done with a C18 column (0.1 v/v% H3PO4) and an ion paring agent such as 5mM heptane sulfonate.

Here is application for separation of clindamycin and benzoyl peroxide. You will need to use two detection techniques as clindamycin has very limited UV:


Clindamycin is retained by combination of weak RP and strong cation-exchange, BP is retained by pure RP mechanism. You can change order of elution for compounds by changing mobile phase composition.
contact me if you have questions.

Can i have the method of analysis?THANKS

All method details are on the slide. You need Primesep 100 mixed-mode column, once you get it I will guide you through method development.