Thermal analysis study of antihypertensive drug doxazosin mesilate

Thermogravimetry and differential scanning calorimetry (DSC) are useful techniques that have been successfully applied in the pharmaceutical industry to reveal important information regarding the physicochemical properties of drug and excipient molecules such as stability, purity and formulation compatibility among others. The present work reports studies of the thermal behavior of antihypertensive drug doxazosin mesilate as raw material and in the form of tablets. The purity was determined by DSC and specialized pharmacopeial method. Analysis of the DSC data indicated that the degree of purity of doxazosin mesilate was similar to that found by the official HPLC method used in the British pharmacopoeia, BP 2011. The simplicity and sensitivity of thermal analysis justify its application in the quality control of pharmaceutical compounds.