Chromatography Forum

Hi all!

Does anyone have worked this drug? It seems that exists in two forms:
FORM I and FORM II.
I analyzed two market products and I have 2 different results!
The HPLC conditions were:
Column HICHROM C18
MP: Buffer-MeCN (80:20)
Det.: 220 nm
Iny.: 20 µl
Sols. 75 mg to 50 ml w/mphase.

For Product 1 the principal peak is at 7.6 min.

For Product 2 the principal peak is at 11.6 min.

Any Ideas? Thanks all the same!

A cursory search of Pubmed indicates there are chiral methods that will separate the enantiomers, however it's possible that your buffer pH or concentration is not facilitating complete conversion of the bisulphate form.

One paper that popped up was;
Analysis of purity in 19 drug product tablets containing clopidogrel: 18 copies versus the original brand. Gomez Y, Adams E, Hoogmartens J.
J Pharm Biomed Anal. 2004 Feb 4;34(2):341-8.

I suggest a 0.02M phosphate buffer at pH=3, but you might find better information from a Pubmed search.

Please keep having fun,

Bruce Hamilton

Hi,

Your question seems interesting. The molecule does have two polymorphs but it means that it has same chemical form but different crystal structure . So ideally they should elute at the same RT in a RP chromatographic system.

No turning to your question, may be two RT's are differnt as you may look at different isomers??? but again it requires a CHIRAL column for seperation.


Request you to check the chromatographic system and also confirm the identity of the two API's

regards,

Yogesh

Please try Bruce's Buffer before anything.