An improved validated ultra high pressure liquid chromatography method for separation of tacrolimus impurities and its tautomers.

A selective, specific and sensitive ultra high pressure liquid chromatography (UHPLC) method was developed for determination of tacrolimus degradation products and tautomers in the preparation of pharmaceuticals. The chromatographic separation was performed on Waters ACQUITY UPLC system and BEH C₈ column using gradient elution of mobile phase A (90:10 v/v of 0.1% v/v triflouroacetic acid solution and Acetonitrile) and mobile phase B (90:10 v/v acetonitrile and water) at a flow rate of 0.

A validated stability-indicating gas chromatography method for determination of divalproex sodium impurities in pharmaceutical preparation.

A stability-indicating gas chromatography (GC) method has been developed and validated for the quantitative determination of divalproex sodium impurities in pharmaceutical preparation. A technique has been developed whereby the peak purity of a compound with poor UV detection can be determined using a gas chromatograph coupled with a mass spectrometer. The drug products were subjected to hydrolysis, oxidation, photolysis, and heat to apply stress conditions.