Example 1. Preparation of rabeprazole Form g. [0023] 100 g of rabeprazole sodium salt (amorphous) is dissolved at approximately 25°C in 450 ml of ethyl acetate. The solution is kept at approximately 25°C and 8 ml of sodium bicarbonate saturated solution is added. The mixture is seeded with a small amount of Form g, then kept under stirring at approximately 25°C for 25 hours. The resulting white solid is filtered by suction, washed with 100 ml of ethyl acetate and dried under vacuum at 45°C. The resulting product has an XRPD spectrum substantially as reported in Figure 1 and a DSC thermogram substantially as shown in Figure 2, which prove that the compound is crystalline. The compound water content determined according to Karl Fischer is approximately 4.5-4.7%. [0024] 1H NMR (300 MHz, DMSO-d6) d (ppm): 8.26-8.24 (d, 1H); 7.48-7.44 (m, 2H); 6.92-6.87 (m, 3H); 4.70-4.66 (d, 1 H); 4.45-4.41 (d, 1 H); 4.09-4.05 (t, 2H); 3.48-3.44 (t, 2H); 3.23 (s, 3H); 2.14 (s, 3H); 1.99-1.93 (q, 2H).