It serves as a reference standard in chromatographic analysis (e.g. HPLCUPLC) to detect identify and quantify impurity L in azithromycin raw materials and finished dosage forms.

Its primary purpose is pharmaceutical quality control helping ensure impurity levels comply with pharmacopeial limits thereby maintaining safety efficacy and stability of the drug.

Azithromycin EP Impurity L is a specified related substance defined in the European Pharmacopoeia for the antibiotic Azithromycin. It is generally formed as a process-related impurity or degradation product during synthesis or storage.