Chromatography Forum

For my FD studies of drug product I am stressing my blend suspension by adding 1 ml of 1 N HCl to blend equivalent to 20mg of API. and incubate the sample for certain time. Idea is to extract the suspension later with DMSO and dilute further to get concentration 250ug\ml(API) for HPLC assay.

Is it necessory that concentration of API for degradation sample should be same as for HPLC assay means 250ug\ml. I can not make 20mg\ml in HCL and dilute later for HPLC assay? Is it going to effect the results?

Hi
When I've done this, I just dilute the FD solution down to my assay concentration and inject immediately. I've never found a need to extract or quench the acidic solution (assuming that your column can handle a bit of low pH..actually, that much a dilution may make the pH moot).

I think the key is to get 5-10% degradation(one of the conditions),