Etter, Jeffrey B., Leigh Ann Webster, Kelly Gonzales, Binhan Lin, Vera Brito, Peter Villax. SUPERCRITICAL FLUID PROCESSING OF A BIOLOGICALLY ACTIVE PEPTIDE
RxKinetix, Inc., 1172 Century Dr., Suite 260, Louisville, CO 80027 (jetter@rxkinetix.com)
Purpose: To investigate the use of supercritical fluid processing to prepare a biologically active, 29 amino acid peptide for pulmonary delivery. Methods: The target peptide was dissolved in various organic solvents and organic solvent mixtures with or without dipalmitoylphosphatidylcholine (DPPC). These solutions were then atomized into flowing supercritical CO2 in various flow configurations. Precipitated peptide was collected on a 0.2mm dead-end filter. Powders were evaluated for MMAD, SEM, Emitted Dose from a DPI and in vivo biological activity. Results: Process yields ranged from 0-92% and were found to be strongly dependent on both the solvent system employed and precipitation chamber configuration. The inclusion of DPPC was found to decrease both particle size and bulk powder density. DPI Emitted Doses were found to be excellent for neat peptide. In vivo, biological activity was unchanged as a result of the supercritical fluid processing.