PEGylation to Improve Protein Stability During Melt Processing

Biopharmaceuticals are some of the most effective drugs on the market, however, delivery remains a challenge. Melt processing is a viable protein encapsulation method because it is solvent free, is high throughput, and yields very high encapsulation efficiencies. Problematically, proteins can lose activity during melt processing due to high heat and shear forces. Covalent attachment of poly(ethylene glycol), or PEGylation, has been widely used to increase thermal stability and prevent aggregation in solution. This study explored the effect of PEGylation on protein stability during melt processing using lysozyme and PLGA. The results indicate that PEGylation increases the retained activity of lysozyme, increases dispersion in the melt, and reduces the biphasic release profile in melt processed systems.