Design of the Amorphous Solid Dispersion (Asd) Drugs by Hot Melt Extrusion (Hme), for the Inhibition of Bone Graft Rejection

This short review paper presents the most important aspects in developing Amorphous Solid Dispersion (ASD) drugs for the inhibition of bone graft rejection, by Hot Melt Extrusion (HME) processing. Types of bone tissue grafts are reviewed. Amorphous solid dispersions (ASDs) drug products are elaborated, including FDA approved ones. Hot Melt Extrusion (HME) technology is discussed for the fabrication of different medication forms. ASD drug products for the inhibition of bone graft rejection are analysed, also related to the immune mechanisms that can lead to immunogenic impairments. Design of the ASD drugs can benefit from considering natural polymer carriers that will inherently prevent harmful immune reactions of the host tissues and enable drug incorporation into the grafts. Addition of new growth factors or bioactive molecules can provide bioactive mechanisms to the grafts and increasingly support cellular growth, proliferation and differentiation and more efficiently prevent atrophic nonunion and graft rejections. Further research on optimization of the ratio of APIs crystallinity to the amorphous polymer carriers, as well as potential of incorporating advanced ASDs formulations into the bone grafts will be studied.