Ternary solid dispersions employing vitamin E TPGS for enhancing dissolution - A comparative study of surfactant combinations and preparation methods

The present study describes the influence of method of preparation and the role of ternary excipient on the solid dispersions prepared employing vitamin E tocopherol polyethylene glycol succinate 1000(Vit E TPGS). Different combinations of TPGS, Soluplus and Gelucire (50/13) are employed and freeze drying and solvent evaporation methods are comparatively evaluated for their efficiency in enhancing the dissolution of furosemide. Freeze drying and solvent evaporation methods were employed to prepare the solid dispersions of furosemide. The dispersions were characterized by dissolution study, X - ray diffraction, Differential Scanning Calorimeter, IR spectrophotometry and SEM study. Free flowing and higher dissolving dispersions could be prepared. The regression analysis of dissolution data suggested that increase in dissolution is an interplay of method employed and the ternary excipient used. The DSC, XRD and SEM studies confirmed that the drug is converted into an amorphous form while the IR spectral studies indicated no interaction between the drug and the carriers used in the investigation. The method of preparation and the ternary excipient influence the extent of improvement of dissolution of poorly soluble drugs.