2,4-D-ALPHA-CYCLODEXTRIN COMPLEXES - PREPARATION AND CHARACTERIZATIONBY THERMAL-ANALYSIS

The aqueous solubility of the pesticide 2,4-D was improved by inclusio n complexation with alpha-CD. The formation of such inclusion compound s was studied via the phase-solubility diagram (solution state) and by DSC and HSM (solid state). 2,4-D presented a typical B-5 Higuchi solu bility curve, coprecipitating a 1:2 pesticide-alpha-CD complex. In ord er to obtain solid complexes, three processing methods were checked: k neading, coprecipitation and spray-drying. DSC and HSM showed that onl y the last two of these yielded true inclusion compounds. Chemical ana lysis also revealed that the stoichiometry of such solid complexes cor responds to a 2,4-D-alpha-CD ratio of 1:2.