Patent ID: 8969309
Filing Date: 2015-03-03
Classification: A61K,A61P,C07K

Abstract:
1. A method for preparing the Crystal B of the peptide substance of formula I, wherein crystal B has peaks at the following 2θ angles in the X-ray diffraction pattern (XRPD): 3.2±0.2°, 5.4±0.2°, 6.2±0.2°, 9.3±0.2° wherein, said method comprises the following steps: (a) dissolving the compound of formula I in an aqueous organic solvent (i) to form solution a; (b) obtaining crystal B of the peptide substance by reducing the temperature of solution a and/or adding another low polarity solvent (ii) into solution a; wherein said organic solvent (i) is selected from one or more of the following group; methanol, ethanol, and acetone.