Fundamentals of Particle Interactions

  • Anthony J. Hickey
  • Stefano Giovagnoli
Part of the AAPS Introductions in the Pharmaceutical Sciences book series (AAPSINSTR)


The behavior of particles in bulk dictates their behavior. The forces of interaction between particles influence their flow and dispersion and the ease with which they can be suspended in any medium. These interactions are in the form of electrostatic and capillary forces that are reciprocally but not linearly related, mechanical interlocking arising from surface asperities and bulk van der Waals forces.

Pharmaceutical inhalation aerosols are a clear example of the way interparticulate forces influence particle behavior and illustrate the considerations that need to be given to these forces.


  1. 1.
    Hickey A. Summary of common approaches to pharmaceutical aerosol administration. In: Hickey A, editor. Pharmaceutical inhalation aerosol technology. 2nd ed. New York: Marcel Dekker; 2004. p. 385–421.Google Scholar
  2. 2.
    Hickey A. Pharmaceutical inhalation aerosol powder dispersion – an unbalancing act. Am Pharm Rev. 2003;6:106–10.Google Scholar
  3. 3.
    Rietema K. The dynamics of fine powders. New York: Elsevier Science Publishing; 1991.CrossRefGoogle Scholar
  4. 4.
    Wuethen T, Roeder S, Brand P, Mullinger B, Scheuch G. In vitro testing of two formoterol dry powder inhalers at different flow rates. J Aerosol Med. 2002;15(3):297–303.CrossRefGoogle Scholar
  5. 5.
    Hickey A, Concessio N, VanOort M, Platz R. Factors influencing the dispersion of dry powders as aerosols. Pharm Technol. 1994;18:58–64.Google Scholar
  6. 6.
    ICRP Task Group on Lung Dynamics. Deposition and retention models for internal dosimetry of the human respiratory tract. Health Phys. 1966;12:173–207.Google Scholar
  7. 7.
    Edwards D, Hanes J, Caponetti G, Hrkach J, Ben-Jebria A, Eskew M, et al. Large porous particles for pulmonary drug delivery. Science. 1997;276:1868–71.CrossRefPubMedGoogle Scholar
  8. 8.
    Hirst P, Pitcairn G, Weers J, Tarara T, Clark A, Dellamary L, et al. In vivo lung depostion of hollow porous particles from a pressurized metered dose inhaler. Pharm Res. 2002;9(10):258–64.CrossRefGoogle Scholar
  9. 9.
    Fults K, Miller I, Hickey A. Effect of particle morphology on emitted dose of fatty acid-treated disodium cromoglycate powder aerosols. Pharm Dev Technol. 1997;2(1):67–79.CrossRefPubMedGoogle Scholar
  10. 10.
    Hickey A, Martonen T. Behavior of hygroscopic pharmaceutical aerosols and the influence of hydrophobic additives. Pharm Res. 1993;10:1–7.CrossRefPubMedGoogle Scholar
  11. 11.
    Hickey A, Ganderton D. Pharmaceutical process engineering. 2nd ed: Informa Healthcare USA; 2010.Google Scholar
  12. 12.
    Crowder T, Hickey A. The physics of powder flow applied to pharmaceutical solids. Pharm Technol. 2000;24(2):50–8.Google Scholar
  13. 13.
    Barrow J. Size, life and landscape. The artful universe the cosmic source of human creativity. New York: Little, Brown and Company; 1995. p. 48–113.Google Scholar
  14. 14.
    Autumn K. Adhesive force of a single gecko foot-hair. Nature. 2000;405:681–5.CrossRefPubMedGoogle Scholar
  15. 15.
    Autumn K. Evidence of van der Waals adhesion in gecko setae. Proc Natl Acad Sci. 2002;99(19):12252–6.CrossRefPubMedGoogle Scholar
  16. 16.
    Jaeger H. The physics of granular materials. Phys Today. 1996;49(4):32–8.CrossRefGoogle Scholar
  17. 17.
    Israelachvilli J. Intermolecular and surface forces. 2nd ed. New York: Academic; 1992.Google Scholar

Copyright information

© American Association of Pharmaceutical Scientists 2018

Authors and Affiliations

  • Anthony J. Hickey
    • 1
  • Stefano Giovagnoli
    • 2
  1. 1.Discovery Science and TechnologyRTI InternationalResearch Triangle ParkUSA
  2. 2.Department of Pharmaceutical SciencesUniversity of PerugiaPerugiaItaly

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