This invention provides a solid pharmaceutical composition comprising rasagiline or a pharmaceutically acceptable salt of rasagiline, and particles having a non-filamentous microstructure of at least two sugar alcohols. This invention also provides a solid pharmaceutical composition comprising rasagiline or a pharmaceutically acceptable salt of rasagiline, a mixture of a disintegrant, a flow agent and particles having a non-filamentous microstructure of at least two sugar alcohols, a supplemental sugar alcohol, a supplemental flow agent, and a supplemental disintegrant. This invention further provides a method of treating a subject afflicted with Parkinson's disease comprising administering to the subject a therapeutically effective amount of the solid pharmaceutical composition, thereby treating the subject. Finally, this invention provides a process of making such solid pharmaceutical compositions.