Chromatography Forum

Dear all,
How do you determine reference standards when we could not find the primary (pharmacopoeial) reference standard? What are the parameters?

Regards,
Siswanto

I'd get a pure sample (with C of A) from the supplier.

Dear SYX

U can make primary standard by analyzing the API for mass balance. U have to characterize it by NMR, Mass etc. and then checking its chromatographic purity, level of impurities, residula solvents, water, heavy metals etc.

By this u can assign a purity to it.

Regards

U can make primary standard by analyzing the API for mass balance. U have to characterize it by NMR, Mass etc. and then checking its chromatographic purity, level of impurities, residula solvents, water, heavy metals etc.
Regards

Any "standard" has to comply with the requirements of the regulators, and the very first questions they will probably ask are
" is it appropriate and equivalant?. "
" is it stable?."

There's little point in characteristing a standard if it's not stable. The initial tests should be purity, then stability.

All of the specifications can be added as defined/suggested by the regulators, such as in ICH Q6A etc. Note that each method will have to comply with quality guidelines, such as ICH Q2.

Nmr is seldom as acceptable as chromatographic separation techniques for any standard purity calculations, but might be a part of the identification process.

Bruce Hamilton