METHOD OF QUANTITATIVE DETERMINATION OF MORPHOLINE DERIVATIVES Russian patent published in 2021 - IPC G01N33/15 

FIELD: pharmaceutics.

SUBSTANCE: invention relates to a pharmaceutical analysis. Disclosed is a method for quantitative determination of morpholine derivatives, involving dissolving of analyzed sample, treatment of an aliquot part of the prepared solution with chemical reagents with subsequent photoelectrocolorimetry of the obtained colored solutions, quantitative determination of the target substance by calibration graphs. Analyzed sample includes exact weighed portions of afobazole, timolol maleate, trioxazine, eprobemide, nimorazole, amorolfine, moclobemide, mefolin or reboxetine, which are dissolved in DMF, aliquot part is treated with excess sodium nitrite solution and concentrated hydrochloric acid is added to pH 4–5, reaction mixture is held for 10 minutes and then added in excess of p-anisidine in a mixture of ethanol 96 % and hydrochloric acid concentrated in volume ratio of ethanol and acid of 17:3 respectively, heated to 30–40 °C on water bath, then, optical density of colored solutions is measured not later than 2 hours on photoelectric colorimeter at 440 nm, comparison solution – p-anisidine in a mixture of ethanol 96 % and hydrochloric acid concentrated in volume ratio of ethanol and acid 17:3 respectively.

EFFECT: invention provides quantitative determination of morpholine derivatives without using toxic solvents with relative determination error not exceeding ±0_47 %.

1 cl, 1 ex, 9 dwg