title: Development of two stable oral suspensions of levodopa-carbidopa for children with amblyopia.
abstract: OBJECTIVE
  To develop stable liquid dosage forms of levodopa-carbidopa for use in children with amblyopia.
  
  
  METHODS
  Levodopa (100 mg) and carbidopa (25 mg) tablets were used to prepare the suspensions at 5 and 1.25 mg/mL, respectively. For each suspension, five bottles were stored at 25 degrees C and five at 4 degrees C. Three samples were taken from each bottle at 0, 7, 14, 28, 42, 56, 70, and 91 days (n=15). Levodopa-carbidopa concentrations for each sample were measured in duplicate by validated and stability-indicating high-performance liquid chromatographic method.
  
  
  RESULTS
  The mean concentrations of levodopa-carbidopa in Ora Plus/Ora Sweet suspensions were 96% and 92% of the initial concentrations for 28 days at 25 degrees C, and 94% and 93% for 42 days at 4 degrees C. In the suspension containing ascorbic acid, the mean concentrations of levodopa-carbidopa were above 93% and 92% for 14 days at 25 degrees C, and 93% and 92% for 28 days at 4 degrees C. This liquid formulation was administered to 15 children (mean age: 5.6+/-1.4 years) with amblyopia. The number and type of adverse effects were similar in the levo-dopa-carbidopa versus placebo group.
  
  
  CONCLUSIONS
  Levodopa-carbidopa in extemporaneous suspensions prepared in Ora Plus and Ora Sweet were stable for 28 days when stored at 25 degrees C and for 42 days at 4 degrees C. Our data suggest our liquid formulation may be used safely in children with amblyopia.
authors.affiliation: Department of Pediatrics and Ophthalmology, College of Pharmacy and Medicine, Ohio State University, Children's Hospital, Columbus 43210, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Nahata
authors.forename: R S
authors.initials: RS
authors.lastname: Morosco
authors.forename: L E
authors.initials: LE
authors.lastname: Leguire
mesh_terms: D000284:Administration, Oral; D000550:Amblyopia / Q000188:drug therapy*; D002230:Carbidopa / Q000737:chemistry / Q000627:therapeutic use*; D002626:Chemistry, Pharmaceutical; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D015259:Dopamine Agents / Q000737:chemistry / Q000627:therapeutic use*; D004355:Drug Stability; D004356:Drug Storage; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007980:Levodopa / Q000737:chemistry / Q000627:therapeutic use*; D008297:Male; D012449:Safety; D013535:Suspensions
chemical_list: D015259:Dopamine Agents; D013535:Suspensions; D007980:Levodopa; D002230:Carbidopa