title: The formation of plasmid DNA loaded pharmaceutical powders using supercritical fluid technology.
abstract: The invention of novel drugs based on biological macromolecules requires the development of specialized formulation methods. Supercritical fluid technology offers the possibility to produce dry powder formulations suitable for inhalation or needle-free injection. In this article we describe the first application of a process involving supercritical carbon dioxide for the production of plasmid DNA-loaded particles. The technique of solution enhanced dispersion by supercritical fluids (SEDS) is used to coformulate the 6.9 kb plasmid pSV beta with mannitol as excipient. After initial experiments showed a high degradation of the plasmid during powder formation, a systematic investigation of the process revealed pH effects to be crucial for the recovery of intact DNA. The application of high-buffer concentration led to an increase of the recovered supercoiled proportion from 7% to 80%.
authors.affiliation: The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Tservistas
authors.forename: M S
authors.initials: MS
authors.lastname: Levy
authors.forename: M Y
authors.initials: MY
authors.lastname: Lo-Yim
authors.forename: R D
authors.initials: RD
authors.lastname: O'Kennedy
authors.forename: P
authors.initials: P
authors.lastname: York
authors.forename: G O
authors.initials: GO
authors.lastname: Humphrey
authors.forename: M
authors.initials: M
authors.lastname: Hoare
mesh_terms: D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005285:Fermentation; D005612:Freeze Drying; D005818:Genetic Engineering / Q000295:instrumentation / Q000379:methods*; D005822:Genetic Vectors; D010957:Plasmids; D011208:Powders; D012997:Solvents; D013314:Stress, Mechanical
chemical_list: D004269:DNA, Bacterial; D011208:Powders; D012997:Solvents