Study of the state of water in a standard sample of flacoside

Abstract

Methods of thermal analysis, including differential scanning calorimetry (DSC) and thermogravimetry (TG), increasingly are being applied in pharmaceutics for the evaluation and development of properties of medicinal phytopreparations and standard substances. The melting temperature and water content are among the most important parameters characterizing the quality of these materials, and can be determined by DSC and TG techniques [ 1 -31.The use of thermoanalytical methods is especially helpful when it is necessary to obtain information on the state of water in various preparations. Other analytical techniques, based on the use of the Fischer reagent and the drying weight loss (DWL) measurements, are capable of determining (in contrast to the thermal analysis) only the quantitative characteristics of preparations. The thermal analysis is aIso advantageous in the case when the Fischer reagent may interact with some chemical groups in the drugs to be analyzed, which excludes its use for the water content determination [4].The purpose of this work was to study the nature of interaction between water and 7-(p-D-glucopyranosyloxy)-8-(3-methylbut-2-enyl)-3,4',5&hydroxyflavanone. EXPERIMENTAL PARTWe have studied the State Standard Sample (SSS) of flacoside used for the certification of plant raw materials, such as the leaves of Phellodendron Amurense and Phellodendron LavaiUeus, and the analysis of flacoside drug in substance and tablets. The phase transitions, connected with evaporation, melting, or decomposition of the objects, were determined by calorimetric measurements on a Perkin-Elmer DSC-2 differential scanning calorimeter. The water content was determined by thermogravimetric measurements on a Perkin-Elmer TGA-7 instrument and by the DWL method. The thermoanalytical measurements were performed in the temperature range from -30 to + 235"C, by heating samples