Overcoming the Bile Salt-Mediated Formation of Nanocolloids That Inhibit Oral Absorption of VX-985.

This article describes the discovery and characterization of nanocolloidal structures formed between VX-985 (an orally administered inhibitor of hepatitis C virus protease) and the bile salt, sodium taurocholate at concentrations of the latter >4 mM. These complexes (1) distribute narrowly in size around a mean diameter of 260 nm, (2) separate from solution only with ultracentrifugation, and (3) appear to influence the absorption of VX-985 from the intestinal tract in vivo, in rodents and humans. Although the oral bioavailability of suspensions of its solid forms is poor, addition of vitamin E D-alpha-tocopherol polyethylene glycol 1000 succinate to dosing vehicles improves the fraction absorbed of the compound in vivo.

Milling-induced disorder of pharmaceuticals: one-phase or two-phase system?

During milling, components are subjected to shear and tensile stresses, which can result in physical phase transformations. The purpose of the work described in this report is to understand the pathway by which two test compounds, d-salicin and γ-indomethacin, undergo a crystalline to amorphous transformation during cryomilling. The results show that the transformation cannot be described by a standard one-phase or two-phase disordering mechanism.