Micellar Solubilization and In Vitro Release of Silymarin in the self-Aggregates of an Amphiphilic Derivative of Chitosan

Summary: The amphiphilic derivatives of chitosan, (2-hydroxyl-3-butoxyl)-propylcarboxymethyl-chitosan (HBP-CMCHS), can form micelles with the inner core of hydrophobic segments and the outer shell of hydrophilic segments. The typical poor water-soluble drug silymarin was solubilized in the HBP-CMCHS micellar by physical entrapped method. Results showed that the solubilizing capacity was enhanced by increasing the concentration of HBP-CMCHS with the same dosage of silymarin. Silymarin-loaded micellar system of HBP-CMCHS was characterized by TEM and DLS. TEM photograph revealed that the micelles were spherical and silymarin was solubilized in the cores of the spherical polymeric micelles. DLS showed that after solubilization the size of the micelles became bigger. In vitro tests showed that silymarin was slowly released from micellar solution and the release lasted up to 40 h by means of the dialysis method.