title: Pharmaceutical design and development of a Sinemet controlled-release formulation.
abstract: Many different formulation techniques are available for designing controlled-release dosage forms. Five different erosion-controlled or diffusion-controlled delivery systems were evaluated to select the 1 most suitable for Sinemet CR. The system ultimately selected, containing carbidopa-levodopa 50-200 mg, is a monolithic matrix tablet designed to have both of its active components released by surface dissolution and erosion. This system was found to be the most effective following extensive in vitro testing, pharmacokinetic studies, and clinical trials. Sinemet CR releases both carbidopa and levodopa by a 1st-order release rate. Controlled-release dosage forms of levodopa with slower in vitro release rates have lower plasma levels.
authors.affiliation: Merck Sharp & Dohme Research Laboratories, West Point, PA 19486.
authors.forename: R E
authors.initials: RE
authors.lastname: Dempski
authors.forename: E C
authors.initials: EC
authors.lastname: Scholtz
authors.forename: E R
authors.initials: ER
authors.lastname: Oberholtzer
authors.forename: K C
authors.initials: KC
authors.lastname: Yeh
mesh_terms: D000978:Antiparkinson Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002230:Carbidopa / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004338:Drug Combinations / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013607:Tablets
chemical_list: D000978:Antiparkinson Agents; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D013607:Tablets; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa