Characterization of the Plasma Apparatus to Develop and Advance the Plasma-based Depyrogenation Process*

Endotoxin deactivation using plasmas has been demonstrated at levels that enables plasma treatment to be classified as a medical depyrogenation device per FDA guidelines. Depyrogenation efficacy was evaluated for synthetic air, nitrogen, and helium plasmas and a 4-log reduction in endotoxin levels was achieved with 30 minutes of treatment. This development of a cost-effective system and identification of the mechanisms that drive plasma-based depyrogenation are in the preliminary stages, but have yielded promising results. Synthesizing endotoxin free chitosan polymer is a challenge for the use of chitosan for internal medicine and drug delivery. A dielectric barrier discharge has been built to perform depyrogenation inside hermetically sealed bags. The FDA requirement for depyrogenation processes is a 3-log reduction in endotoxin levels. Along with demonstration of a 4-log reduction, this study looks at the post-plasma treatment modifications in the chitosan polymer and surface modifications of different bag materials (low-density polyethylene, Nylon, and Teflon FEP) using FTIR and Raman spectroscopy. Measurements for the applied power, bag surface temperatures, optical emission spectroscopy, and gas temperatures were carried out to characterize the plasma apparatus.