Description_x000D_ General description_x000D_ Amphotericin B is a polyene antifungal antibiotic from Streptomyces sp. It has a high affinity for sterols,primarily ergosterols, of fungal and bacterial cell membranes.After binding to sterols, it forms channels in the membranes, causing small molecules to leak out.Amphotericin B is effective against fungi and yeast.The name of the drug is derived from the amphoteric behavior of the drug, due to the carboxyl group on the main ring and a primary amino group on the mycosamine ring._x000D_ Amphotericin B induces K+ leakage, which is separate from its lethal action, as was demonstrated in human erythrocytes and is due to the inhibitory effect on the Na+/K+ pump.At sub-lethal concentrations, this drug stimulates either the activity of some membrane enzymes or cellular metabolism,in particular stimulation of some cells of the immune system._x000D_ Preparation Note_x000D_ If reconstituted at 25 mg/10 mL of sterile water, there is no need to filter sterilize. This will yield a slightly hazy yellow solution._x000D_ Storage and Stability_x000D_ Amphotericin B remains active for 3 days in culture at 37°C. For long term, storage at 2−8°C, protected from air and light, is recommended. Under these conditions the products remain active for 5 years.