DSC experiments were performed on aqueous solutions of PEO-PPO-PEO (P105) amphiphiles in the low concentration regime (0-1%) to resolve the critical micelle concentration (cmc) both neat and co-formulated with methylparaben (MP). Further work was done at 10% amphiphilic copolymer concentrations and co-formulated with MP to resolve the variations in enthalpy. The compensation temperature, T-compensation, was determined from the analyses for neat P105 as 293.9 K; adding MP raises this to 328.43 K. (C) 2013 Elsevier Inc. All rights reserved.