THERMAL STUDY OF COMPLEX-FORMATION OF TRIAMTERENE WITH BETA-CYCLODEXTRIN BY SPRAY-DRYING AND CO-GRINDING

The formation of crystalline inclusion complex of triamterene with beta-cyclodextrin (beta-CD) was studied, evaluating the thermal behaviour and dispersion state of this drug in different types of binary systems. Spray-drying and co-grinding (oscillating mill) mixtures of triamterene with beta-CD were prepared in 1:1 molar ratio. The changes of crystalline properties of original (untreated) triamterene, beta-CD, and composites obtained by co-grinding and spray-drying were investigated in comparison with those produced in simple physical mixtures. The thermal behaviour of the different samples was investigated using DTA. X-ray diffraction was applied as a complementary technique. The results have been explained by formation of amorphous drug particles on spray-drying samples and co-grinding or alternatively by means of a solid dispersion formation or a combination of these two. A contamination effect by grinding media was also observed as increasing grinding time.