title: Lack of bioequivalence between generic risperidone oral solution and originator risperidone tablets.
abstract: Risperidone is an atypical anti-psychotic, available in various formulations.
  
  
  OBJECTIVE
  The objective of the study was to compare the bioavailability of a generic oral solution of risperidone (Test formulation) and Risperdal tablets (Reference formulation). Both formulations contained 1 mg risperidone per dosing unit.
  
  
  METHODS
  The study was carried out in 32 healthy volunteers under fasting conditions. Risperidone and 9-hydroxyrisperidone concentrations in plasma were determined using HPLC/MS/MS.
  
  
  RESULTS
  The results show that the 90% confidence intervals for the geometric mean ratios of the solution and the tablet formulations were not within the acceptance range of 80 125% for risperidone, whereas the confidence intervals for 9-hydroxyrisperidone were within the acceptance range of 80 - 125%.
  
  
  CONCLUSIONS
  Bioequivalence between the generic 1 mg/ml risperidone solution and the originator tablet formulation was not proven in this study.
authors.affiliation: Synthon BV, Nijmegen, The Netherlands. sandra.vanos@synthon.nl
authors.forename: S
authors.initials: S
authors.lastname: van Os
authors.forename: M
authors.initials: M
authors.lastname: Relleke
authors.forename: P Muniz
authors.initials: PM
authors.lastname: Piniella
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D016001:Confidence Intervals; D018592:Cross-Over Studies; D016568:Drugs, Generic / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000097:blood; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D000068882:Paliperidone Palmitate; D019999:Pharmaceutical Solutions; D011743:Pyrimidines / Q000097:blood; D018967:Risperidone / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013607:Tablets; D013810:Therapeutic Equivalency
chemical_list: D014150:Antipsychotic Agents; D016568:Drugs, Generic; D007555:Isoxazoles; D019999:Pharmaceutical Solutions; D011743:Pyrimidines; D013607:Tablets; D018967:Risperidone; D000068882:Paliperidone Palmitate