In vitro permeability drugs evaluation in intestinal tissue of rats. Applications in biopharmaceutical classification

• Grant number: 09/02063-4
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2009
• End date: November 30, 2011
• Field of knowledge: Health Sciences - Pharmacy - Pharmaceutical Technology
• Principal Investigator: Cristina Helena dos Reis Serra
• Grantee: Cristina Helena dos Reis Serra
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Bioavailability is the determining factor of drug clinical efficacy and it depends directly on permeability and solubility properties of the active substance . The Biopharmaceutical Classification System (BCS), based on these characteristics, has been proposed to work as a tool aiming at the development of pharmaceutical forms, whether it contains new drugs or not, with the objective of providing assistance in the prediction of its availability in vivo, since there are technical, economic and ethical limitations with regard to the direct tests of bioavailability. Thus, the evaluation of drugs permeability and solubility, even through an indirectly way, provides objective information on the effectiveness of medicines, with the advantage that in vitro models offer more easily reproducible and represent no risk to healthy volunteers. The studies of permeability in vitro may be achieved by different techniques, such as the methods which employ intestinal tissue obtained from different animals, artificial membranes and monolayers of cells obtained by cell culture models, using synthetic membranes, chromatographic methods with immobilized artificial membranes and computational models. However, there is a lack of standardized protocols for studies of permeability and solubility and many of the available literature on these important properties neither are reliable nor conclusive. Accordingly, this project proposes to evaluate the drug permeability (zidovudine and lamivudine) in segments of rat intestine through an in vitro model using camera vertical diffusion (Franz cells). (AU)