METHOD FOR QUANTITATIVE DETERMINATION OF DERIVATIVES OF UNSUBSTITUTED ARYLSULFONAMINES Russian patent published in 2023 - IPC G01N33/15 

FIELD: pharmaceutical analysis.

SUBSTANCE: invention relates to the analysis of medical preparations using optical means. A method for the quantitative determination of alkylaryl sulfone derivatives is described. The method includes dissolving accurate weighed portions of celecoxib, sulpiride, bumetanide, mafenide, and probenecid in dimethylformamide at room temperature. In this case, an aliquot of the derivatives of alkylarylsulfones is treated with an excess, relative to the component to be determined, of 0.01 Μ of a solution of SnCl₂ in concentrated HCl. Then hot concentrated hydrochloric acid is added to achieve pH 2–4 and the solution is boiled for 45 min on a water bath. After that, the solution is cooled to room temperature, a mixture of distilled water and hot concentrated hydrochloric acid taken in a volume ratio of 1:1 is added to create a pH of 2–4. The solution is kept for 3 minutes at 30–40°C in a water bath and cooled to room temperature. Then 0.01 Μ aqueous solution of NaOH is added to achieve pH 8–10 and excess is gradually added in drops, in relation to the component being determined, an aqueous solution of sodium nitroprusside in 0.1 Μ KOH. The resulting solution is kept for 5 minutes until an orange color appears, after which 0.05 ml of a 5% ammonium sulphate solution is added. The absorbance of the coloured solutions is then measured at 374 nm. As a reference solution, a solution of sodium nitroprusside in 0.1 Μ KOH is used.

EFFECT: technical result is in expanding the range of methods for the quantitative determination of alkylarylsulfone derivatives by developing a sensitive method for the quantitative determination of celecoxib, sulpiride, bumetanide, mafenide and probenecid in substances by colorimetry with a relative error of not more than ±0.65% in the absence of the use of toxic reagents.

1 cl, 5 dwg, 1 ex