Lack of Bioequivalence Between Generic Risperidone Oral Solution and Originator Risperidone Tablets

S van Os, M Relleke, P Muniz Piniella

Int J Clin Pharmacol Ther. 2007 May;45(5):293-9.

PMID: 17542352

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%.













Conclusion:




Bioequivalence between the generic 1 mg/ml risperidone solution and the originator tablet formulation was not proven in this study.