Characterization of Chitosan Polymeric Ethosomes Capable of Encapsulating Hydrophobic and Hydrophilic Drugs Prepared by a Microemulsion Method

Abstract

Polymeric ethosomes,formed from amphiphilic octadecyl quaternized carboxymethyl chitosan (OQCMC)with different degrees of quaternary substitution(DS),were prepared by the microemulsion(ME) method.These ethosomes could simultaneously encapsulate both the hydrophobic drug indomethacin (IMC)and the hydrophilic drug vincristine(VCR).The effects of the DS of the OQCMC and primary alcohols as cosurfactants on the phase diagram were elucidated.The prepared nanoparticles(NPs)were small((52.40±0.55)nm)and suitable as drug carriers for different drugs.The maximum drug loading efficiencies of VCR-loaded and IMC-loaded NPs were 22.7%and 20.1%,respectively.The drug loading capacities for co-delivery of VCR and IMC were 12.2%and 10.0%,respectively.OQCMC polymeric ethosomes were stable in aqueous solution and exhibited slow,steady drug release.Hydrophilic fluorescein isothiocyanate(FITC)and hydrophobic Nile Red were encapsulated by the OQCMC ME NPs and simultaneously delivered into HO8901 cells with green and red fluorescence,respectively.This co-delivery system may allow for temporally distinct classes of drugs for cancer therapy.