1. Roberts, D. L., J. P. Mitchell, “Quality Requirements for Cascade Impactors Assigned to Batch Release Testing of a Specific Drug Product; Part III:  Implications of Type II Error Probability,” Inhalation14(6), December 2020, pages 10-16.
  2. Versteeg, H. K., D. L. Roberts, F. Chambers, A. Cooper, M. Copley, J. P. Mitchell, “A Cross-Industry Assessment of the Flow Rate-Elapsed Time Profiles of Test Equipment Typically Used for Dry-Powder Inhaler (DPI) Testing:  Part 2 – Analysis of Transient Air Flow in the Testing of DPIs with Compendial Cascade Impactors,” Aerosol Sci. Tech., 54(12), 1448-70 (2020).
  3. Greguletz, R., P. U. Andersson, A. Cooper, F. Chambers, M. A. Copley, G. Daniels, M. Hamilton, M. Hammond, H. Mohammed, D. L. Roberts, C. Shelton, H. K. Versteeg, J. P. Mitchell, “A Cross-Industry Assessment of the Flow Rate-Time Profiles of Test Equipment Typically Used for Dry-Powder Inhaler (DPI) Testing:  Part 1 – Compendial Apparatuses,” Aerosol Sci. Tech., 54(12), 1424-47 (2020).
  4. Roberts, D. L., F. Chambers, M. Copley, J. P. Mitchell, “Internal Volumes of Pharmaceutical Compendial Induction Port, Next-Generation Impactor With and Without Pre-separator, and Several Configurations of the Andersen Cascade Impactor With and Without Pre-separator,” J. Aerosol Med. Pulmon. Drug Del., 33(4), 214-29 (2020).
  5. Roberts, D. L., J. P. Mitchell, “Quality Requirements for Cascade Impactors Assigned to Batch Release Testing of a Specific Drug Product; Part II:  The Concept of ‘Sufficient’ as Applied to Impactor Quality Specifications,”
    Inhalation13(6), December 2019, pages 18-25.
  6. Roberts, D. L., “Quality Requirements for Cascade Impactors Assigned to Batch Release Testing of a Specific Drug Product; Part I: A Grassroots Look,” Inhalation, 13(4), August 2019, pages 10-16.
  7. Roberts, D. L., J. P. Mitchell, “Measurement of Aerodynamic Particle Size Distribution of Orally Inhaled Products by Cascade Impactor:  How to Let the Product Specification Drive the Quality Requirements of the Cascade Impactor,” AAPS Pharm. Sci. Tech., DOI:10.1208/s12249-018-1276-9 (2019).
  8. Roberts, D. L., M. Svensson, K. Sandell, D. Sandell, “Experimental and Theoretical Investigation of a New Approach to In-Use Impactor Quality Specifications,” Drug Delivery to the Lung 2018, Edinburgh, UK, The Aerosol Society, December 12-14, 2018.
  9. Mitchell, J. P., C. Blatchford, R. Greguletz, D. L. Roberts, H. Versteeg, “A European Pharmaceutical Aerosol Group (EPAG)-Led Cross-Industry Assessment of Inlet Flow Rate Profiles of Compendial DPI Test Systems:  Part 1 – Experimental Data,” Drug Delivery to the Lung 2018, Edinburgh, UK, The Aerosol Society, December 12-14, 2018.
  10. Roberts, D. L., H. Versteeg, C. Blatchford, R. Greguletz, J. P. Mitchell “A European Pharmaceutical Aerosol Group (EPAG)-Led Cross-Industry Assessment of Inlet Flow Rate Profiles of Compendial DPI Test Systems:Part 2 – First-Order Impactor Model,” Drug Delivery to the Lung 2018, Edinburgh, UK, The Aerosol Society, December 12-14, 2018.
  11. Dolovich, M. B., J. P. Mitchell, D. L. Roberts, “Re: ‘Harmonizing the Nomenclature for Therapeutic Aerosol Particle Size: A Proposal,’ by Hillyer et al.,” J. Aerosol Med. Pulmon. Drug Del., 31(4), 1-3 (2018).
  12. Roberts, D. L., C. M. Shelton, “A Practical Method for Eliminating Type I and Type II Errors when Assessing the Suitability for Continued Use of a Cascade Impactor,” Inhalation, April 2018, pages 12-18.
  13. Roberts, D. L., N. Maidment, M. A. Copley, “Improved Protocol for Relating Impactor Stage Pressure Drop to the Suitability for Routine Use,” Drug Delivery to the Lung 2017, Edinburgh, UK, The Aerosol Society, December 6 to 8, 2017, pg. 94-7.
  14. Roberts, D. L., J. P. Mitchell, “Suitability of Used Impactors – Why the ‘Effective Diameter’ Criterion Needs the ‘Jet-to-Plate’ Criterion to Assure Measurement Capability in a Good Cascade Impactor Practice (CGIP) Environment,” Drug Delivery to the Lung 2017, Edinburgh, UK, The Aerosol Society, December 6 to 8, 2017, pg. 306-10
  15. Roberts, D. L., J. P. Mitchell, “Spatial Aerosol Flow Maldistribution: A Design Flaw Confounding the Proper Calibration and Data Interpretation of Stages ‘0’ and ‘1’ of the Andersen Eight-Stage Nonviable Cascade Impactor,” Aerosol Sci. Tech., 50, 1-12 (2016). Download PDF here.
  16. Roberts, D. L., J. P. Mitchell, ““The Next Generation Impactor (NGI™) – Manufacturing Control: Part II.  Collection Cups and the Critical Jet-to-Plate Distance,” Inhalation, August 2016, pages 9-15.
  17. Roberts, D. L., J. P. Mitchell, “The Next Generation Impactor (NGI™) – Manufacturing Control: Part I. Nozzles,” Inhalation, April 2016, pages 12-19.
  18. Nichols, S. C., J. P. Mitchell, C. M. Shelton, D. L. Roberts, “Good Cascade Impactor Practice (GCIP) and Considerations for ‘In-Use’ Specifications,” AAPS Pharm. Sci. Tech., 14(1), 375-90 (March 2013).
  19. Roberts, D. L., J. P. Mitchell, “Influence of Stage Efficiency Curves on Full-Resolution Impactor Data Interpretation,” Drug Delivery to the Lung, The Aerosol Society, Edinburgh, Scotland, December 7-9, 2011, pp. 181-4.
  20. Roberts, D. L., J. P. Mitchell, “The Effect of Nonideal Cascade Impactor Stage Collection Efficiency Curves on the Interpretation of the Size of Inhaler-Generated Aerosols,” AAPS Pharm. Sci. Tech., 14 (2), 497-510 (June 2013).
  21. Roberts, D. L., “Theory of Multi-Nozzle Impactor Stages and the Interpretation of Stage Mensuration Data,” Aerosol Sci. Tech., 43, 1119-29 (2009).
  22. Marple, V. A., B. A. Olson, K. Santhanakrishnan, D. L. Roberts, J. P. Mitchell, B. L. Hudson-Curtis, “Next Generation Pharmaceutical Impactor: A New Impactor for Pharmaceutical Inhaler Testing.  Part III.  Extension of Archival Calibration to 15 L/min,” J. Aerosol Med., 17, 335-43 (2004).
  23. Marple, V. A., D. L. Roberts, F. J. Romay, N. C. Miller, K. G. Truman, M. Van Oort, B. Olsson, M. J. Holroyd, J. P. Mitchell, D. Hochrainer, “Next Generation Pharmaceutical Impactor — Part I: Design,” J. Aerosol Med., 16, 283-99 (2003).
  24. Marple, V. A., D. L. Roberts, B. Y. H. Liu, “Efficient High-Productivity Cascade Impactors,” US Patent 6,453,758, September 24, 2002.