Ceramide-based nanostructured lipid carriers for transdermal delivery of isoliquiritigenin: Development, physicochemical characterization, and in vitro skin permeation studies

An optimized, ceramide-based, nanostructured lipid carrier (NLC) formulation was developed for isoliquiritigenin (ILTG), and its potential as a transdermal delivery system was evaluated. ILTG-loaded NLCs were prepared by blending solid (ceramide, cholesterol) and liquid lipids (caprylic/capric triglyceride) in various proportions using a hot homogenization and ultrasonication method. The physicochemical characteristics were investigated by DLS, ZP, EE%, TEM, DSC and XRD analyses and in vitro skin permeation studies. The results showed that the particle size of the formulation was 150.19–251.69 nm with a ZP>−20mV. The EE% was 56.45–89.97%. The NLC structure was influenced by lipid ratio, and increasing the caprylic/capric triglyceride ratio caused a less ordered structure, as confirmed by DSC. The XRD analysis indicated that ILTG was not in the crystalline state in all formulations. The skin permeation study showed that the ILTG-NLCs promoted ILTG permeation. In conclusion, ceramide-based NLCs could be a promising vehicle for the ILTG transdermal delivery of ILTG.