Polymorphs of Donepezil hydrochloride and processes feeder for their preparation

Donepezil hydrochloride, l-benzyl-4- [(5,6-dimethoxy-l-indanone) -2-yl] metylpiperidinhydroklorid, is provided in the form of tie polymorphs that are stable to heat and fiikti ^ a by pharmaceutical use. They can be produced industrially. They are specified by peaks in X-pulverdiffrak- sjonsmonstie and absorption peaks in infrared absorption spectra in potassium bromide.