In this study, differential scanning calorimetry and thermogravimetry were employed to determine the thermal behavior of LPSF/FZ4 isolated and associated with excipients (amide, beta-cyclodextrin, cellulose, lactose, stearate of magnesium, aerosil, sodium lauryl sulfate, polysorbate and polyvinylpyrrolidone). Thus, the purity of the prototype calculated was 98%. Isothermal and non-isothermal methods were used to determine the kinetic parameters of decomposition, finding a first-reaction order and activation energy (A(e)) of 98.22 kJ mol(-1). Also, the time of the stability of LPSF/FZ4 was measured in 4 months. The compatibility study showed possible interactions of the prototype with lactose due to a change in its heat of fusion, a reduction of more than 40 degrees C in its stability and a reduction of approximately 30% in A(e) of its decomposition reaction. The study demonstrated the importance of using thermal analytical methods to characterize new drugs to enable the development and quality control of pharmaceutical products. (C) 2013 Elsevier B.V. All rights reserved.