The effect of the structural transition within a direct hexagonal (HI) mesophase on the internal lipid mobility

•Development of a transdermal temperature-controlled H1 lyotropic liquid crystal.•Lipid mobility is a critical attribute in transdermal formulation development.•Low lipid mobility within direct aggregates enhances drug transdermal penetration.•Mobility of lipophilic drugs within direct aggregates promotes dermal accumulation.•T1/T2 NMR correlations were found to be adequate for lipid mobility determination.