What is claimed is:
1. A liquid formulation comprising a protein and an excipient compound selected from the group consisting of hindered amine compounds, aromatic compounds, functionalized amino acids, oligopeptides, short-chain organic acids, low molecular weight aliphatic polyacids, and sulfones, wherein the excipient compound is added in a viscosity-reducing amount.
This application is a continuation-in-part of U.S. application Ser. No. 14/966,549 filed Dec. 11, 2015 which is a continuation of U.S. application Ser. No. 14/744,847 filed Jun. 19, 2015 which claims the benefit of U.S. Provisional Application No. 62/014,784 filed Jun. 20, 2014, U.S. Provisional Application No. 62/083,623, filed Nov....