Disclosed is a single unit oral dose pharmaceutical composition comprising: a) Levodopa or salts thereof from about 50mg to about 300mg along with one or more rate-controlling polymer for extended release b) Carbidopa or salts thereof from about 10mg to about 100mg along with one or more rate-controlling polymer for extended release and c) Entacapone or salts thereof from about 100mg to about 1000mg along with one or more pharmaceutically acceptable excipients for immediate release, wherein the pharmaceutical composition optionally comprise one or more other pharmaceutically acceptable excipients. Further disclosed is a process for preparing a said pharmaceutical composition, and the use of said composition in the manufacture of a medicament for treating Parkinsons disease.
