**Abstract**

Amorphous ternary solid dispersion has become one of the strategies commonly used for improving the solubility and bioavailability of poorly water soluble drugs. Such multicomponent solid dispersion can be obtained by different techniques, this chapter provides an overview of ternary solid dispersion by comilling method from the perspectives of physico-chemical characteristics in vitro and in vivo performance. A considerable improvement of solubility was obtained for many active pharmaceutical ingredients (e.g., Ibuprofen, Probucol, Gliclazid, Fenofibrate, Ibrutinib and Naproxen) and this was correlated to the synergy of multiple factors (hydrophilicity enhancement, particle size reduction, drug-carrier interactions, anti-plasticizing effect and complexation efficiency). This enhanced pharmacokinetic properties and bioavailability of these drug molecules (1.49 to 15-folds increase in plasma drug concentration). A particular focus was accorded to compare the ternary and binary system including Ibuprofen and highlighting the contribution of thermal and spectral characterization techniques. The addition of polyvinylpyrrolidone (PVP K30), a low molecular weight molecule, into the binary solid dispersion (Ibuprofen/β-cyclodextrin), leads to a 1.5–2 folds increase in the drug intrinsic dissolution rate only after 10 min. This resulted from physical stabilization of amorphous Ibuprofen by reducing its molecular mobility and inhibiting its recristallization even under stress conditions (75% RH and T = 40°C for six months).

**Keywords:** amorphous ternary solid dispersion, co-milling, PVP, physical stability, aqueous solubility, bioavailability, Ibuprofen
