SPECTROPHOTOMETRIC METHOD FOR QUANTITATIVE DETERMINATION OF SODIUM O- [(2,6-DICHLOROPHENYL)AMINO]PHENYLACETATE IN PRESENCE OF POLYMER WATER-SOLUBLE COMPONENTS OR IN COMMON PRESENCE THEREOF AND SUBSTANCES CONTAINING PHENYL RESIDUE IN DRUG COMPOSITIONS Russian patent published in 1997 - IPC

FIELD: analytical chemistry. SUBSTANCE: one prepares solution of preparation to be determined, solution of standard sample of sodium O-[(2,6- dichlorophenyl)amino] phenylacetate, and fixative (substance with absorption maximum at 292-299 nm) solution. Spectrum of standard sample solution is registered relative to fixative solution in the wavelength range 294 to 300 nm and wavelength value is then chosen at which absorption minimum is observed. At this wavelength, optical density of preparation under analysis is measured relative to fixative solution (D_x/D_f) as well as that of standard sample (D_s/D_f) relative to the same solution. Afterward optical density of fixative solution (D_f) at chosen wavelength is measured relative to solvent used in preparing fixative solution. Optical densities of test preparation (D_x) and standard sample (D_f) solutions are further measured relative to methyl or ethyl alcohol at wavelength 335 nm. Finally, value of (D_f+D_x/D_f-D_x)/(D_f+D_s/D_f-D_o) is calculated as a basis to judge of content of sodium O-[(2,6-dichlorophenyl)amino] phenylacetate in drug composition. EFFECT: enabled sodium O-[(2,6- dichlorophenyl)amino]phenylacetate determination in drug compositions containing various polymer components. 3 tbl