This research evaluates the temperature effect in the stability of extemporaneous compounding of captopril, enalapril and verapamilo, prepared itself of generic formulations of tablets. Three extemporaneous compounding formulations were elaborated containing captopril, enalapril and verapamilo active principle coming from the GENFAR laboratory using a simple syrup and methyl cellulose mixture as vehicle. Both formulations were put under tests of stability to temperatures of 5ºC (41ºF), 25ºC (77ºF), 40ºC (104.ºF) and 60ºC (140ºF ) evaluating temporary variations of the percentage of captopril, enalapril and verapamilo not degradated until the 18 days. The samples were quantified by method High performance liquid chromatography (HPLC). The speed of degradation (K0) and the time of expiration of the prepared have been considered. The percentage of medicaments surpluses at 5º, 25, 4...