Processes for producing pharmaceutical excipients from lignocellulosic biomass, and pharmaceutical excipients obtained therefrom

Abstract

In some variations, the invention provides a process for producing a microcrystalline cellulose material, comprising: fractionating lignocellulosic biomass feedstock in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin; chemically and/or mechanically treating the cellulose-rich solids to form microcrystalline cellulose having an average crystallinity of at least 60%; and recovering the microcrystalline cellulose as a pharmaceutical excipient. The pharmaceutical excipient may function as an antiadherent, a binder, a coating, or a disintegrant. In some embodiments, the pharmaceutical excipient further comprises a lignin-derived lubricant, glidant, sorbent, preservative, or other component. The pharmaceutical excipient may be present in a pill, tablet, capsule, powder, slurry, or other pharmaceutically effective and acceptable form.

What is claimed is: 
     
         1 . A pharmaceutical excipient comprising lignocellulosic biomass-derived nanocellulose having an average crystallinity of at least 60%, wherein said pharmaceutical excipient is a pharmaceutically effective antiadherent, binder, coating, and/or disintegrant. 
     
     
         2 . The pharmaceutical excipient of  claim 1 , wherein said pharmaceutical excipient further comprises a lignin-derived lubricant, glidant, sorbent, or preservative. 
     
     
         3 . A pharmaceutical pill, tablet, capsule, powder, or slurry produced by a process comprising:
 (a) providing a lignocellulosic biomass feedstock;   (b) fractionating said feedstock in the presence of a sulfur-containing compound, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein said sulfur-containing compound is selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, lignosulfonic acid, and combinations thereof;   (c) chemically and/or mechanically treating said cellulose-rich solids to form nanocellulose having an average crystallinity of at least 60%;   (d) recovering said nanocellulose; and   (e) incorporating said nanocellulose into a pharmaceutical pill, tablet, capsule, powder, or slurry.