Pharmaceutical composition and preparation method thereof

A solvent-free method of preparing an oral solid pharmaceutical composition comprising pharmacologically effective amounts of entacapone, levodopa and carbidopa, or a pharmaceutically acceptable salt or hydrate thereof, and one or more pharmaceutically acceptable excipients, which comprises

• a) simultaneous mixing of pharmaceutically effective amounts of entacapone, levodopa and carbidopa, or a pharmaceutically acceptable salt or hydrate thereof, together with at least one pharmaceutically acceptable excipient having an equilibrium moisture content of at least 2% to obtain a first mixture,
• b) granulating the first mixture to obtain granules, if necessary;
• c) adding a lubricant to the first mixture of step a) or to the granules of step b) to obtain a second mixture;
• d) formulating the second mixture into an oral solid composition;
• and
• e) if desired, coating the composition obtained in step d).