Dissolution properties and in vivo behaviour of triamterene in solid dispersions with polyethylene glycols

The applicability of the solid dispersion technique as a method for enhancing the GI absorption of a drug has been explored in order to procure better dissolution characteristics and better bioavailability for triamterene. The physicochemical characterization of the systems has shown the absence of chemical reaction between the drug and the polymers during the solid dispersion elaboration process (melting carrier method). In vitro release profiles have been studied and quantified in terms of dissolution efficiency over the first 30 min (DE30) and dissolution percentage over the first 30 min (DP30). The results have shown that there were no significant differences between the three polyethylene glycols (PEGs) under test. The in vivo effectiveness of the different preparations was also investigated by means of the urinary volumetric excretion (UVE)--pharmacologic effect--and by the estimation of Ke, tmax, and MRT-pharmacokinetic parameters. At end, an analysis of the relative bioavailabilities between formulations has been performed.