title: Evaluation of excipients for enhanced thermal stabilization of a human type 5 adenoviral vector through spray drying.
abstract: We have produced a thermally stable recombinant human type 5 adenoviral vector (AdHu5) through spray drying with three excipient formulations (l-leucine, lactose/trehalose and mannitol/dextran). Spray drying leads to immobilization of the viral vector which is believed to prevent viral protein unfolding, aggregation and inactivation. The spray dried powders were characterized by scanning electron microscopy, differential scanning calorimetry, Karl Fischer titrations, and X-ray diffraction to identify the effects of temperature and atmospheric moisture on the immobilizing matrix. Thermal stability of the viral vector was confirmed in vitro by infection of A549 lung epithelial cells. Mannitol/dextran powders showed the greatest improvement in thermal stability with almost no viral activity loss after storage at 20°C for 90days (0.7±0.3 log TCID50) which is a significant improvement over the current -80°C storage protocol. Furthermore, viral activity was retained over short term exposure (72h) to temperatures as high as 55°C. Conversely, all powders exhibited activity loss when subjected to moisture due to amplified molecular motion of the matrix. Overall, a straightforward method ideal for the production of thermally stable vaccines has been demonstrated through spray drying AdHu5 with a blend of mannitol and dextran and storing the powder under low humidity conditions.
authors.affiliation: Department of Chemical Engineering, McMaster University, Hamilton, Ontario L8S 4L7, Canada.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: LeClair
authors.affiliation: Department of Chemical Engineering, McMaster University, Hamilton, Ontario L8S 4L7, Canada.
authors.forename: Emily D
authors.initials: ED
authors.lastname: Cranston
authors.affiliation: McMaster Immunology Research Centre & Department of Pathology and Molecular Medicine, McMaster University, Canada.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Xing
authors.affiliation: Department of Chemical Engineering, McMaster University, Hamilton, Ontario L8S 4L7, Canada. Electronic address: mthomps@mcmaster.ca.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Thompson
mesh_terms: D000072283:A549 Cells; D000260:Adenoviruses, Human / Q000235:genetics*; D002152:Calorimetry, Differential Scanning; D003910:Dextranase; D005079:Excipients / Q000737:chemistry*; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000737:chemistry; D006801:Humans; D006813:Humidity; D007785:Lactose / Q000737:chemistry; D007930:Leucine / Q000737:chemistry; D008353:Mannitol / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011208:Powders; D013696:Temperature; D013997:Time Factors; D014199:Trehalose / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D005079:Excipients; D011208:Powders; D008353:Mannitol; D014199:Trehalose; D003910:Dextranase; D007930:Leucine; D007785:Lactose
keywords: Adenovirus; Moisture uptake; Spray drying; Thermal stability; Vaccine; Viral vector