[Solubility of the polyene antibiotics nystatin and levorin in water-organic mixtures].

Solubility of the polyenic antibiotics levorin and nystatin in water-alcohol mixtures and in the water-acetone system was studied. Methanol, ethanol, n-propanol, isopropanol and n-butanol were used as alcohols. It was shown that the water-n-propanol system had the maximum dissolving properties with respect to levorin and nystatin.

[Spectrophotometric determination of nystatin].

New equations for spectrophotometric calculation of the concentrations of nystatin and its semiproducts in the finished drugs are presented. The results obtained with the use of these equations correlated with those of the biological assay. It was found that the difference in the standard deviations with regard to the one-point procedure for the assay of nystatin, the method of 3 equidistant wavelengths and the method of the background algebraic correction was statistically insignificant.