Solubility measurements at equilibrium were performed for the systems (3 beta,25R)-spirost-5-en-3-ol (diosgenin) and (16 alpha,17 beta)-estra-1,3,5(10)-triene-3,16,17-triol (estriol) in at least 12 solvents at atmospheric pressure within the temperature range T = (293.2-328.2 K) using combined digital thermal analysis and thermal gravimetric analysis (DTA/TGA) to determine compositions at saturation. The results were modelled with the NRTL and Tsuboka-Katayma modified Wilson activity coefficient models. The models employed provided a satisfactory correlation of the experimental data. Furthermore melting points and enthalpies of melting of diosgenin and estriol were determined by combined DTA/TGA. (C) 2016 Elsevier Ltd.