| abstract |
The invention discloses a crystal form A of tretinoin and a preparation method thereof, wherein characteristic peaks are arranged at diffraction angles 2 theta of 13.26 +/-0.2, 14.56 +/-0.2, 15.34 +/-0.2, 19.90 +/-0.2, 20.60 +/-0.2, 22.66 +/-0.2, 24.84 +/-0.2 and 27.18 +/-0.2 degrees in a powder X-ray diffraction pattern of the crystal form. The crystal form A of tretinoin has good stability, is very important for preparing high-quality medicines, and has excellent repeatability after repeating a plurality of batches within the process parameter range of the preparation method. |