High purity crystalline forms of peptides Arg-Lys-Asp and Arg-Lys-Asp-Val, process for preparing them and pharmaceutical compositions containing them

摘要

The present invention relates to a process for the preparation of high purity crystalline forms of peptides Arg-Lys-Asp and Arg-Lys-Asp-Val from crude, amorphous peptides Arg-Lys-Asp and Arg-Lys-Asp-Val. The process is characterized in that the crude, amorphous peptide Arg-Lys-Asp or peptide Arg-Lys-Asp-Val is allowed to stand at room temperature with 5 to 20 unit volume of an ethanolic solution containing 0.5 to 4.0% by volume of acetic acid and 5 to 25% by volume of water, wherein the volume unit is calculated for the mass unit of the material and mass unit relates to volume unit as g relates to ml, then the crystallized peptide is separated from the crystalline suspension, preferably after cooling. Pharmaceutical compositions containing the crystalline forms of these peptides are also described.