Patent ID: 8592601

Claim:
A process for preparing the magnesium salt of an omeprazole enantiomer in dihydrate form A, comprising: a step of controlled dehydration by drying at: (i) a temperature of between 40 and 65° C., under a pressure of 1 bar or under vacuum, or (ii) a temperature of between 20 and 40° C., under vacuum and/or at 0% relative humidity, of crystals of a magnesium tetrahydrate salt of an omeprazole enantiomer, said crystals being obtained by filtration and then drying of a suspension containing a precursor phase of said magnesium tetrahydrate salt, wherein the precursor has an X-ray diffractogram of the following characteristic peaks: d 2-Theta Relative (Angströms) (°) intensity (%) 19.80 4.45 very strong 12.17 7.25 weak 10.78 8.19 medium 9.26 9.53 weak 7.28 12.14 weak 6.79 13.03 weak 5.22 16.95 weak 5.01 17.67 medium 4.821 18.38 weak 4.009 22.15 weak.