[Sisomicin. The mechanism of admixture inactivation and formation].

Inactivation of sisomicin in aqueous solutions was studied under various conditions. At pH 4-10 and a temperature of 60 degrees C the inactivation rate constant was equal to (5-10) X 10(-5) hour-1 and remained stable. At lower pH values the inactivation rate constant increased: 5.

[Determination of the sulfate ion content in antibiotic sulfate salts by a complexometric titration method].

A possibility of assaying antibiotic sulfates, such as gentamicin, kanamycin, monomycin, neomycin, ristomycin, streptomycin, florimycin and polymyxin M sulfates for sulfate ions by titration with barium chloride in the presence of chlorphosphonaso-III, a metal indicator immediately in the salt solutions or after elimination of the cation by means of ion exchange (sulfocation exchange resins in H+-form) was tested. The procedure was shown to be adequate to the classical weight method.

[Cephalosporin C stability in aqueous solutions].

Stability of cephalosporin C in aqueous solutions at various temperatures was studied. The kinetic parameters of the inactivation process providing estimation of the inactivation rate constant of cephalosporin C at pH 0-12.5 and various temperatures were evaluated.

[Gentamicin stability and a method for its quantititive determination].

Stability of gentamycin in solutions at various pH levels was studied. It was shown that in acid media inactivation proceeded according to the equation of the 1st order reaction. Dependence of the inactivation rate constant on the temperature corresponded to Arrenium equation.