Azithromycin is a semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis. Azithromycin anhydrous is a macrolide antimicrobial. The chemical classification of azithromycin anhydrous is macrolides. Azithromycin is an azalide antibiotic, which inhibits the growth of gram negative bacteria, such as haemophilus influenza. Azithromycin functions by interfering with 50s ribosomal subunit formation and translation, which inhibits the formation of proteins essential for bacterial survival studies involving capillary electrophoresis suggest that azithromycin can be used as a chiral selector for enantiomeric separation of compounds. In addition, azithrmycin can be used to increase chloride efflux and selectively reduces tumor necrosis factor α in human cystic fibrosis cells. Furthermore, azithromycin reduces lps-induced pulmonary neutrophilia in mice, via suppressing the expression of il-1β.