congresos y reuniones científicas
Formulation of liposomal preparations containing arginine-based surfactants
FAIT, M.E.; HERMET, M.; CAIMI, A.; PÉREZ, A. P.; ROMERO, E. L.; MORCELLE, S.R.; BAKÁS, L.
Congreso; XLVII Reunión Anual de la Sociedad Argentina de Biofísica; 2018
Sociedad Argentina de Biofísica
Two novel arginine-based cationic surfactants, Nα-benzoyl-arginine decylamide (Bz-Arg-NHC10) and Nα-benzoyl-arginine dodecyl amide (Bz-Arg-NHC12), were synthesized using papain (an endopeptidase from Carica papaya latex) adsorbed onto polyamide as biocatalyst. Nα-benzoyl-arginine ethyl ester hydrochloride (the classical substrate for the determination of cysteine and serine proteases activity) was used as arginine donor, whereas decyl- and dodecylamine were used as nucleophiles for the condensation reaction, with yields higher than 80%. The purification process was achieved by a single cationic exchange chromatographic separation, involving the use of water and ethanol as the main separation solvents. Liposomal formulations made of soy phosphatidylcholine (SPC) as phospholipids (10 mg.mL-1) and Bz-Arg-NHCn (n=10 or 12; 20-40% mol.mol-1) as edge activators were prepared by the thin-film hydration method. The liposomal suspensions were sonicated (60 min with a bath-type sonicator, 80 W, 40 KHz) and extruded 10 times through two stacked 0.2 μm and 0.1 μm pore polycarbonate filters using a 100 ml Thermobarrel extruder. Size (liposomal diameter) and zeta potential were determined by dynamic light scattering and phase-analysis light scattering, respectively. The deformability values (D) of the liposomes were also calculated and phospholipids were quantified by a colorimetric phosphate microassay. For storage stability characterization, mean size, polydispersity and Z potential were measured upon storage during 3 weeks at 4°C in darkness. Based on these results, both arginine-based surfactants could be used as additives in topical formulations exerting their activity on the skin surface.