Context: Furosemide is an anionic molecule and has very low absorption in gastro intestinal tract.
Objective: The aim of this study was to investigate the effect of anionic macromolecules on the intestinal permeability of Furosemide.
Materials and methods: The intestinal permeability of Furosemide was determined using single-pass intestinal perfusion technique in rats. Briefly a jejunal segment of ∼10 cm was isolated and cannulated in both ends for inlet and outlet solution. The perfusate was collected every 10 min and samples were analyzed using the RP-HPLC method. Test samples containing furosemide and two anionic macromolecules, sodium carboxy methyl cellulose and sodium alginate, at different concentrations were used.
Results: The obtained data showed that existence of Sodium carboxy methyl cellulose significantly increased the Peff values in all three investigated concentrations (p < 0.05) but sodium alginate only in concentrations <0.1% increased drug permeability.
Discussion: It is concluded that the anionic macromolecules at specific concentrations could alter the permeability of anionic drugs across the biological membranes.
Conclusions: Donnan phenomenon and chelating property of macromolecules could be attributed to the observed effect.
Keywords: Donnan effect; furosemide; single-pass intestinal perfusion.