[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.

[Metrological evaluation of spectrophotometric and polarimetric methods in determining the griseofulvin content in the finished product].

Correctness and reproducibility of the results of spectrophotometric and polarimetric determinations of the griseofulvin content in the finished products were studied with the use of reference griseofulvin and the samples of the antibiotic industrial lots. It was shown that the relative standard deviation in determination of E1CM1% ranged within 1.6--4.

[Differential spectrophotometric method of analysing levorin in the culture broth and in the mycelium].

It was shown on model experiments that the microbiological method was not applicable for determination of levorin content in industrial intermediate products containing in addition levoristatin, since the presence of the latter made higher the results of the microbiological assay. Because of this till to the present date the quantitative content of levorin in the industrial intermediate products was determined photometrically using alcohol (pure solvent) as the reference solution. Still, this method also made higher the results of the assay, especially when the content of levorin was determined in the fermentation broth.