Investigation of furosemide dialysis rate in the presence of anionic polymers

Abstract

The aim of the present study was to determine the in vitro dialysis of furosemide, an anionic drug, in the presence of anionic macromolecules. The polymers (sodium carboxymethylcellulose, sodium alginate, and methylcellulose) were used at different concentrations, and the drug concentration in the dialysis bag was 250 μg/mL. The entire process was performed in a receptor chamber in which a dialysis bag was placed as a donor medium. The samples were collected at different times up to 4 h at 37 °C. Finally, the samples were analyzed by UV spectrophotometry at 277.5 nm. Methylcellulose was used as a neutral macromolecule to show the influence of polymer viscosity in the dialysis process. The dialysis rate increased with increasing macromolecule concentration up to a certain limit. This effect could be explained by Donnan equilibrium. Polyelectrolytes (e.g., sodium alginate and sodium carboxymethylcellulose) enhance the transport rate of ionic drugs with the same electrical charge. However, the increased medium viscosity in the dialysis process limits the Donnan effect. It is concluded that anionic macromolecules in specific concentrations could be used as transport-enhancer excipients for anionic drugs such as furosemide.