ABSTRACT
A method for monitoring the manufacture of genetically engineered human insulin by HPLC was developed. The method was validated by the estimation of its linearity, correctness, accuracy, specificity, and stability; the limits of detection and quantitative assessment were also determined. It was proven that HPLC analysis enables reliable and reproducible results to be obtained and can be used for monitoring insulin manufacture.
Subject(s)
Drug Contamination/prevention & control , Insulin/chemistry , Genetic Engineering , Humans , Insulin/genetics , Quality Control , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Reference StandardsABSTRACT
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.
Subject(s)
Carbenicillin/pharmacology , Malonates/pharmacology , Penicillin G/pharmacology , Solvents/pharmacology , Water/pharmacology , Carbenicillin/isolation & purification , Hydrogen-Ion Concentration , Malonates/isolation & purification , Mathematics , Penicillin G/isolation & purificationABSTRACT
The dependency of L-asparagine hydrolysis rate on L-asparagine concentration in the presence of L-asparaginases from E. coli and Erw. carotovora is studied in a broad pH range. Km values are calculated from the data obtained. It is found that Km insignificantly depends on pH value with the pH range of 5-9 for both asparaginases. Sharp Km maximum is observed at pH greater than 9 in both cases. The maximum position does not coinside with enzyme isoelectric points and with the region of the substrate transition from zwitterionic form into anionic one.
