Caracterización en fase sólida de complejos de hidroclorotiazida con β-ciclodextrina

ONNAINTY, R., MORA, M.J., LONGHI, M.R., GRANERO, G.E.

Rosario

Congreso; 2º Reunión Internacional de Ciencias Farmacéuticas, RICiFa; 2012

Introduction: Hydrochlorothiazide (HCT) is a diuretic class of thiazides. This drug is poorly soluble in water and slightly permeable through intestinal mucosa, therefore it belongs to IV group of Biopharmaceutical Classification System. To improve these unfavorable biopharmaceuticals properties was used like strategy inclusion complex between HCT and β-cyclodextrin (β-CD). CDs have an exterior hydrophilic surface and a lipophilic central cavity. There are able to form inclusion complex with a big variety of molecules, both in solid state and aqueous solutions. Encapsulations of the molecule affect its physicochemical properties, resulting in most of the studies case, an improving of solubility and permeability through the membranes. Materials and methods: Solid systems HCT:β-CD (1:1) were obtain by lyophilized and physic mixture of their compounds. Characterization of the same was done by thermic analysis (DSC – TG) and by infrared spectroscopy (FT-IR). Thermic profiles and FT-IR spectrums of the solid systems were compared with those of its pure compounds. Results: Results obtained by thermic analysis, we can observe that in the physic mixture maintaining the corresponding peaks to the dehydration of the β-CD and the fusion of the HCT, while than in the lyophilizes system, observe a thermogram attributed to the presence of a new phase, as the curves didn’t be equals. This can be than in the lyophilized system, the HCT will be included in the hydrophobic cavity of the β-CD and in this hydrophobic environment the cavity will determinate a different thermic behavior. The result obtain by FT-IR spectroscopy get attribute the change observed in the HCT/β-CD lyophilized system FT-IT spectrum the formation of an inclusion complex, because is produced a shift in the frequency and a change in the absorptions bands shape of the functional groups of HCT. Instead, these changes aren’t observed in the mixture physic of the HCT/β-CD system. Conclusion: Obtained results with this study getting confirm an inclusion complex formation between HCT and β-CD, and suggest that the HCT login completely to the CD hydrophobic cavity.