Anhydroerythromycin A is a degradation product of the macrolide antibiotic erythromycin. Anhydroerythromycin A is formed via degradation of erythromycin in acidic aqueous solutions in vitro as well as in vivo. Anhydroerythromycin A is active against S. aureus and B. cereus in vitro (MICs = 12.5 and 6.25 μg/ml, respectively). Anhydroerythromycin A also inhibits steroid 6β-hydroxylase activity associated with the cytochrome P450 (CYP) isoform CYP3A in human liver microsomes.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.