then cooled to 20 30 u00b0 c and precipitated by the metered addition of 281 5 kg of 25 ammonia solution the product precipitated is centrifuged washed with water and dried at 120 125 u00b0 c 150 kg of telmisartan recrystallised from dimethylformamide or dimethylacetamide 7 5 kg of activated charcoal 750 l of ethanol and 30 kg of 25 aqueous ammonia solution are placed in a 1200 l stirring apparatus the mixture is stirred for about 1 h and then filtered into another 1200 l stirring apparatus and washed with 150 l of ethanol the mixture is heated to 70 80 u00b0 c 35 kg of glacial acetic acid are added and the mixture is stirred for a further 1 5 2 h at 75 80 u00b0 c the mixture is then cooled to 0 10ic and stirred for a further 2 h the product precipitated is centrifuged washed with 300 l of ethanol and with 300 l of water and dried at 70 90 u00b0 c in the preparation process according to the invention as a result of the partial conversion of the polymorphic form b into the polymorphic form a during the drying process telmisartan occurs as a pure substance in a mixture of two polymorphic forms however this does not affect the properties of the pharmaceutical composition as in the course of the manufacture of telmisartan tablets for example the mixture of the polymorphic forms a and b is dissolved in 0 1 n naoh solution and converted by spray drying into a homogeneous and totally amorphous granulate which is then subjected to the other tablet making steps for more detailed information on.