Thermal studies of Albizia inopinata crude extract in the presence of cyclodextrin and Aerosil® by TG and DSC coupled to the photovisual system

Albizia inopinata (Harms) G.P. LEWIS has been studied for its anti-hypertensive/vasodilater phytopharmaceutical effects. In this work TG and DSC are coupled to a photovisual system and were used to determine the thermal behavior of A. inopinata dried extract prepared with and without stabilizers. The extracts were prepared by percolation of the powdered leaves in an ethanol:water (70:30) solvent system for 72 h and then dried using a spray–dryer technique. Aerosil® 200 (Colloidal silica dioxide) and β-cyclodextrin were used as stabilizers for the preparation of the dried extracts. TG curves were obtained using a Shimadzu thermobalance, model TGA-50H. DSC curves were obtained with a Shimadzu calorimeter, model DSC-50, coupled to the photovisual system. TG curves for A. inopinata extracts and Albizia-stabilizers exhibited six thermal decomposition stages. DSC curves showed phase transition differences among the samples. The pictures obtained by DSC photovisual showed thermal behavior differences between the products.