[A method of quality control of 3-phenyl-5-methylisoxazole-4-carbonic acid chloranhydride using high performance liquid chromatography]. / Metod kontrolia kachestva khlorangidrida 3-fenil-5-metilizoksazol-4-karbonovoi kisloty s pomoshch'iu vysokoéffektivnoi zhidkostnoi khromatografii.

A method of quantitative determination of 3-phenyl-5-methyl-isoxazole-4-carbonyl chloride useful for its qualitative estimation at all stages of oxacillin industrial synthesis was developed. The methods is based on transformation of this semi-product into isopropyl ester followed by high efficiency liquid chromatography with the use of the "Milikhrom" chromatograph mad in the USSR. A variant of the typical method for determination of 3-phenyl-5-methyl-isoxazole-4-carbonyl chloride concentration in solution is described.

[Distribution of carbenicillin, benzylpenicillin and phenylmalonic acid in an organic solvent-water system]. / Raspredelenie karbenitsillina, benzilpenitsillina i fenilmalonovoi kisloty v sisteme organicheskii rast voritel'-voda.

Distribution of carbenicillin, benzylpenicillin and phenylmalonic acid in butyl acetate-water and methylene chloride-water systems within wide ranges of pH of the aqueous phase was studied. The experimental data were reviewed taking into account the distribution between the phases of the compound molecules and dissociation of the acids in the aqueous solution. The distribution constants of the compound molecules were calculated to be 37 (the literature data), 11.6 and 5.2 for every antibiotic respectively in the first system and 10 and 0.24 for carbenicillin and benzylpenicillin in the second system (the value for phenylmalonic acid was not calculated). When the concentration of carbenicillin in butyl acetate is high, dimerization of the acid molecule in the nonaqueous phase should be taken into the account. The dimerization constant is equal to 16.6 M-1.