The pressure-temperature phase diagram of morniflumate (niflumic acid beta-morpholinoethyl ester) has been obtained by high-pressure thermal analysis. In addition, calorimetric melting data (T-I -> L = (348.1 +/- 0.4) K and Delta H-I -> L = (89 +/- 2) J.g(-1)) and the specific volumes of the solid and the liquid state have been obtained under normal pressure. Comparison of the measured high-pressure melting data with the equilibrium curve obtained through the Clapeyron equation indicates that the initial slopes are the same (dP/dT = (2.96 +/- 0.06) MPa.K-1) at the melting point under normal pressure. The fact that the Clapeyron equation can be used to construct topological phase diagrams may be of interest for the food and pharmaceutical industries. (C) 2017 Elsevier Ltd.