Physicochemical characterization of solid dispersion of furosemide with TPGS.

The D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was used to increase the aqueous solubility and dissolution rate of furosemide. The solid dispersion of furosemide with TPGS was prepared by solvent method using methanol. The aqueous solubility and the dissolution rate of furosemide were rapid and markedly enhanced from the 1:2 furosemide-TPGS solid dispersion. The X-ray diffractometry showed that pure furosemide and furosemide contained within the physical mixture were crystalline in nature, whereas furosemide in the solid dispersion was not in crystalline form. The infrared spectroscopic analysis showed that an interaction, in the solid dispersion, such as an association between the functional groups of furosemide and TPGS might occur in the molecular level. The infrared spectroscopy and differential thermal analysis showed the physicochemical modifications of the furosemide from the solid dispersion. The solid dispersion technique with TPGS provides a promising way to increase the solubility and dissolution rate of poorly soluble drugs.