The invention relates to an administration unit comprising 0.1 µg to 2 g of a crystalline form or pharmaceutical acceptable salt of N-(6-((2R,3S)-3,4-dihydroxybutan-2-yloxy)-2-(4-fluorobenzylthio)pyrimidin-4-yl)-3-methylazetidine-1-sulfonamide. The invention also relates to a packaging comprising one or more such administration units.