Method for purification of torasemide and preparation of big crystal form

Abstract

The invention discloses a method for purification of torasemide and preparation of big crystal form, which is characterized in that Torasemide crude is dissolved in acidulous solvent to raise the temperature to 85-100 DEG C; the mixture is stirred for dissolved clarification and is decolorized and filtered; the temperature of filtrate is slowly lowered to 5-30 DEG C for crystallization; crystal is obtained by filtering and separating; and then the obtained product is dried at the temperature of 50-70 DEG C to obtain purified Torasemide crystal. The invention has the advantage of simple processing method and can obtain the crystal of which the purity is 99% and average grain diameter is 50-350 mu m by dissolving, crystallizing and purifying.

Description

technical field The invention relates to the field of pharmaceutical processing methods, in particular to a purification and crystallization method of torasemide Background technique Torsemide is commercially available as a trademark, and its chemical name is 1-isopropyl-3-[(-m-toluidinyl-3-pyridyl)sulfonyl]urea, and the U.S. FDA recognizes the compound as Torsemide rice (torsemide). As a new safe and effective powerful diuretic, torasemide can not only treat edema caused by congestive heart failure, but also has a potassium-sparing effect, and has a good curative effect on mild and moderate hypertension. The drug was first launched in France in 1993, and later in Italy, Belgium, the United Kingdom, Japan and other countries. Due to its good clinical efficacy and high safety, it was approved by the FDA in August 1993 and launched in the United States. Diuretics are clinically widely used as first-line therapeutic drugs for hypertension and heart failure due to their defin...

AI Technical Summary

Problems solved by technology

The disadvantage of the existing purified torasemide production method is that the yield or purity is unsatisfactory, and the yield is usually 50-60%, and the purity is below 98.5%.

Especially reduce the content of related substance 3-sulfamoyl-4-(3'-methylphenyl)aminopyridine, there is no better method at present