Chromatography Forum

Hi,

Please help if you are interested in challenging separation.
1) all the following separation need to pass PDA purity test (wave length 200 to 300nm) and Rs >2.3;

2) separated the oxidation degradants from phenylephrine (20mg phenylephrine in 10 mL water containing 1 mL 3% H2O2 is heated over steam bath for 15 min to get the oxidation);

3) the same for CPM as 2) except for 30 min heating for CPM oxidation;

4) separate the impurity peak coming with sample diluent 0.2M KH2PO4 and showing up around CPM

5) the whole method run time < 30 min for separation of the all three actives in the title.

Excel,

we will take the challenge, we have bunch of method for cough medications. A lot of these compositions have the same compounds in differnt ratios (ephedrines, acetaminophen, chrlorpheniramine, phenylephrine, doxylamine, etc.).

Here is some links for you:
http://www.sielc.com/application_122.html
http://www.sielc.com/compound_166.html
http://www.sielc.com/compound_116.html

We also have couple more methods which are not on the web yet. I'll send you few files in couple of days.

Regards,

Vlad

Vlad,

first of all, thank you for the two methods(since 122=166). they are good works but I will only put down my concerns.
before we know how your methods separates the api from their impurity and degradants, for 122/166, 1) it is running gradient without even base line, which we do not like as for quantitation. and 2)i am not sure the Rt for chlor(less hydrophilic , afraid to be long);
for 116, if we make the Rt for phenylephrine >3.5min(double of the void), i afriad 1) the peak shape of acetaminophen makes me think phenylephrine was not separated from its degradants w/ Rs>2.3; 2) also may long Rt for chlor.