The evaluation of some techniques of thermal analysis at the preformulation stage of combined drugs

Abstract

Introduction. Thermal analysis includes several analysis techniques, which measure an analytical signal of the sample at a certain temperature. The analysis is based on thermogravimetric curves. The instrument used in thermal analysis consists of a microbalance surrounded by a electrically heated furnace equipped with a thermocouple to monitor the temperature. Aim of the study. is to assess the use of of thermo-gravimetric and differential scanning calorimetry methods at the preformulation stage of combined drugs. Materials and methods. Electronic databases: Medline, Cochrane, Embase and Springer. Also, the search was conducted by using printed, pharmaceutical and chemical journals. It was analyzed 150 bibliographic sources. Results. In most of the researches (45%), thermogravimetric analysis was used in order to determine the decomposition temperature of the individual active substances and also from the mixtures of active substances with excipients or with other active substances. Also, most frequently (53.3%), thermogravimetric analysis has been combined with other techniques such as: differential scanning calorimetry. Less researches (1.7%) applied thermogravimetric method to determine water content and volatile substances. Conclusions. Thermogravimetry and differential scanning calorimetry are physicochemicalmethods which are widely used for compatibility research of active substances and excipients at the preformulation stage of drugs.