Design and synthesis of a series of novel, cationic liposaccharide derivatives as potential penetration enhancers for oral drug delivery

Oral delivery remains a challenge for a number of drug candidates with low absorption profile (poor membrane permeability, lack of stability, solubility issues or susceptibility to enzymatic degradation) and various methodologies have been investigated to overcome it. The approach presented here consists of associating, by ion-pairing, a hydrophilic, ionizable model drug to a series of synthetic counter-ionic entities with a controlled degree of lipophilicity in order to enhance its penetration of biomembranes and offer some protection against in situ degradation, while preserving its biologically active chemical structure. We report herein the synthesis of a series of positively charged potential penetration enhancers designed from d-glucose, 2-aminododecanoic acid, and additional lipophilic amino acids, and converted afterward into quaternary ammoniums in an optimized, innovative one-step reaction. Each liposaccharide derivative synthesized was fully characterized and their ability to generate micelles in solution was assessed by isothermal titration calorimetry.