Coacervation-responsive cubosome containing hyaluronic acid and albumin complex

Coacervation-responsive cubosomes were prepared by loading a complex of hydrophobically modified hyaluronic acid (HmHA) and hydrophobically modified albumin (HmAlb) and steviol glycoside (SG) into the water channels. Hyaluronic acid and albumin were modified with a lipid chain, and the HmHA and HmAlb were characterized by ¹H NMR and FT-IR spectroscopy, respectively. The formation of the HmHA/HmAlb coacervate complex was optimized when the mass ratio was 1:9 under pH 4.0 conditions. The phase transition temperature of the cubic phase complex was observed to increase slightly from 60.9°C to 61.6°C as a result of the inclusion of the coacervate complex, as evidenced by differential scanning calorimetry. The maximum release degree of SG at 22°C was suppressed to 30.9% due to the coacervate at pH 3, and it was promoted to 75.9% at pH 5.5 due to the dissolution of the electrostatic complex as the pH value increased. The monoolein of the cubosDome enhanced the in vitro skin permeation of the cubosomal SG, as it could play a role as a skin permeation enhancer. The coacervation-responsive cubosome could be potentially used as a drug carrier that can release its content in a pH-controlled manner.