Characterization and Comparison of the Solid State Inclusion Compounds of alfa-, beta-Cyclodextrins and its 2-Hydroxypropyl Derivatives with Uracil and 5-fluorouracil

Abstract

The objective of the present work was to obtain and evaluate the solid inclusion complexes of a-, b-cyclodextrins and hydroxypropyl-a-, hydroxypropyl-b-cyclodextrins derivatives with uracil (U) and anti-cancer agent 5-fluorouracil (5FU). The thermogravimetry (TG), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) and scanning electron microscopy (SEM) were used to characterize these inclusion compounds. New information on the physicochemical behavior of these solid state complexes synthesized by melting in solution was obtained. Corelating the experimental data we found that the complexation occurs for each host:guest system thus, the preparation method exhibited a real efficiency to interaction achievements. The inclusion capability and the thermal stability of the studied complexes were due to both the flexibility and the size of the cyclodextrin ring as well the stereoelectronic effect of the U or 5FU molecule. We appreciated that the complexes between U or 5FU with 2-hydroxypropyl derivatives of a- and b- CD have the largest content of guest and are the most stable. The obtained results could be useful in formulation of the pharmaceutical products and also in drug delivery.