Background::
Knowledge of the permeation characteristics of new chemical entities across biological
membranes is essential to drug research and development. Transport medium composition may affect the absorption of
compounds during in vitro drug transport testing. To preserve the predictive values of screening tests, the possible
influence of transport media on the solubility of model drugs, and on the activities of tight junctions and efflux transporter
proteins (e.g. P-glycoprotein) must be known.
Objective::
The aim of this study was to compare the impact of different transport media on the bi-directional transport of
standard compounds, selected from the four classes of the Biopharmaceutical Classification System (BCS), across excised
pig intestinal tissue.
Methods::
The Sweetana-Grass diffusion apparatus was used for the transport studies. Krebs-Ringer bicarbonate (KRB)
buffer and simulated intestinal fluids in the fed (FeSSIF) and fasted (FaSSIF) states were used as the three transport
media, while the chosen compounds were abacavir (BCS class 1), dapsone (BCS class 2), lamivudine (BCS class 3) and
furosemide (BCS class 4).
Results::
Abacavir exhibited lower permeability in both the simulated intestinal fluids than in the KRB buffer. Dapsone
showed similar permeability in all media. Lamivudine exhibited lower permeability in FaSSIF than in the other two
media. Furosemide exhibited improved transport with pronounced efflux in FaSSIF.
Conclusion::
Different permeation behaviors were observed for the selected drugs in the respective media, which may
have resulted from their different physico-chemical properties, as well as from the effects that dissimilar transport media
components had on excised pig intestinal tissue.