In Situ Intestinal Perfusion in Rodents: Future Perspectives for Application on Absorption Studies and Classification of Drugs.

Background: In 1995, the Biopharmaceutics Classification System (BCS) was proposed by Amidon and colleagues as a tool that considers two important parameters regarding drugs: solubility and permeability. Since then, several methods for solubility and permeability studies have been developed for drug delivery and absorption prediction. In recent years, permeability has gained a great highlight and the interaction between a molecule and a biological membrane is not enough to predict the in vivo behavior of a compound.

Single-Pass Intestinal Perfusion (SPIP) and prediction of fraction absorbed and permeability in humans: A study with antiretroviral drugs.

In recent years, the prediction of oral drug absorption in humans has been a challenge for researchers and many techniques for permeability studies have been developed for several purposes, including biowaiver processes. The Single-Pass Intestinal Perfusion (SPIP) method performed in rats can provide permeability results closest to in vivo condition. The purpose of the present study was to evaluate the intestinal permeability of the antiretroviral drugs lamivudine, stavudine and zidovudine using the SPIP method in rats and to predict their permeability (Peff,humans) and fraction absorbed (Fa) in humans.

Evaluating Potential P-gp Substrates: Main Aspects to Choose the Adequate Permeability Model for Assessing Gastrointestinal Drug Absorption.

The success of an oral drug route administration depends on many factors that interfere in its bioavailability, therapeutic efficacy and clinical safety. In human cells, ATP-dependent efflux transporter proteins, such as P-glycoprotein (P-gp), BCRP and MRP2, reduce the absorption of drugs. A tiered approach chosen to evaluate drugs as substrates or inhibitors of efflux pumps, particularly P-gp, should be carefully selected, since each study method has advantages and intrinsic limitations to their processes.