The Effect of Counterions in Hydrophobic Ion Pairs on Oral Bioavailability of Exenatide
Thi Nhu Quynh Phan, Ruba Ismail, Bao Le‐Vinh, Sergey Zaichik, Flavia Laffleur, Andreas Bernkop‐Schnürch
Abstract
of exenatide from -1.9 to 2.0 for exenatide-SOS and to 1.2 for exenatide-DOC. SEDDSs loaded with 0.26% (m/m) exenatide-SOS and 0.17% (m/m) exenatide-DOC had mean droplet size less than 30 nm and negative zeta potential. Ex vivo permeation experiments revealed 3.5-fold and 6.4-fold improvement in membrane permeability of the exenatide-SOS-loaded SEDDS vs. the exenatide-DOC-loaded SEDDS and exenatide solution, respectively. The orally administered exenatide-SOS-loaded SEDDS and exenatide-DOC-loaded SEDDS resulted in relative oral bioavailability vs. subcutaneous injection (SC) of 19.6 and 15.2%, respectively. Within this study, the key role of counterions for oral peptide delivery via HIP could be confirmed, and SOS was identified as a promising surfactant for this purpose.