It is used as a reference standard in analytical testing especially in HPLCUPLC methods to detect identify and quantify impurity levels in azithromycin bulk drug and finished formulations.

Its main purpose is quality control and regulatory complianceensuring that impurity levels remain within pharmacopeial limits for safety efficacy and stability of the drug.

Azithromycin EP Impurity H is a specified related substance (impurity) identified in the European Pharmacopoeia for the antibiotic Azithromycin. It is typically a degradation or process-related byproduct formed during synthesis or storage of azithromycin.