Investigation of the influence of the release rate of metoprolol from the dosage form on its absorption process and on its enantiomers' absorption process

• Grant number: 08/08799-0
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2010
• End date: January 31, 2013
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Valentina Porta
• Grantee: Valentina Porta
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

ANVISA, the Brazilian regulatory agency for drug products, does not require the use of enantioselective bioanalytical methods in bioequivalence assays of generic and similar drug products containing racemic drugs. Therefore, it is possible that two formulations are bioequivalent based on plasmatic concentration of total drug, but are not bioequivalent on the basis of the comparison of the data of the stereoisomers. The objective of this study is to investigate the influence of the release rate of metoprolol from the dosage form on its absorption process and on its enantiomers' absorption process by measuring plasmatic concentrations of total metoprolol, S-metoprolol and R-metoprolol after oral administration of drug products containing racemic metoprolol. An in vivo bioavailability study will be conducted according to national and international guidelines for biomedical research involving human subjects. Three metoprolol administration schemes will be used to simulate different drug release rates from the drug product. Blood samples will be collected for metoprolol and its enantiomers quantification, and pharmacokinetic parameters will be calculated to compare the different drug release rates. (AU)