Method for acquiring IV crystal form tolbutamide by adding single-stranded oligodeoxynucleotide

The invention discloses a method for acquiring IV crystal form tolbutamide by adding single-stranded oligodeoxynucleotide. The method includes the steps of: (1) conducting ultrasonic treatment on a supersaturated tolbutamide solution to dissolve it, with the solvent of the tolbutamide solution being ethanol and water in a volume ratio of 2:1; (2) filtering the solution subjected to ultrasonic treatment by an organic filter membrane with an aperture of 0.22micrometer to remove insoluble matters, adding single-stranded oligodeoxynucleotide to reach a concentration of 0.2-2.0mg/L, and oscillating and mixing the substance evenly; (3) cooling the mixed solution obtained in step (2) to 4DEG C at a cooling rate of 1-10DEG C/min; and (4) performing crystallization at 4DEG C for 3-12h, conducting pumping filtration, and drying the obtained crystals at room temperature for 12-36h so as to obtain the IV crystal form tolbutamide. The method provided by the invention adopts single-stranded oligodeoxynucleotide as a drug c