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Pharmaceutical Research

, Volume 6, Issue 3, pp 225–229 | Cite as

Optimized Inhalation Aerosols. I. The Effects of Spherical Baffle Size and Position upon the Output of Several Pressurized Nonaqueous Suspension Formulations

  • Peter R. Byron
  • Richard N. Dalby
  • Anthony J. Hickey
Article

Abstract

Baffles contained in conventional actuators may be a convenient alternative to some of the extension devices used presently with metered-dose inhalers (MDIs). Actuators were modified to determine whether baffles could be used to decrease the output of large “nonrespirable” droplets. These actuators were tested using a series of nonaqueous suspension aerosols containing 0.1 to 2.0% micronized disodium fluorescein (DF) as the model drug, stabilized by sorbitan trioleate in a constant blend of fluorocarbons 11, 12, and 114. A 25-µl metering volume was used throughout. Aerosol output was characterized by cascade impaction. Baffle size and position had pronounced effects on actuator retention and aerosol output. Increasing baffle size resulted in increased retention in the actuator. The total output of the MDI in the “respirable” range (aerodynamic diameter, Dae, <5.5 µm) was greater in the unbaffled actuator than in all baffled actuators. However, all baffles increased the respirable fraction (DF with Dae <5.5 µm: total DF leaving the actuator), R, when compared to their unbaffled controls. For example, for a 0.1% DF, 0.14% surfactant formulation, R was increased from 0.40 (unbaffled) to 0.71 by incorporation of a 0.6-cm-diameter sphere 1.3 cm from the jet of the actuator. In these cases, aerosol segregation occurred due to droplet inertia in the high velocity gas flows. Increasing the respirable fraction at the expense of the total respirable output may obviate undesirable clinical effects.

aerosol suspensions particle size formulation inhalation baffles sprays inertial capture 

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REFERENCES

  1. 1.
    P. R. Byron. Drug Dev. Ind. Pharm. 12:993–1015 (1986).Google Scholar
  2. 2.
    S. P. Newman. Deposition and Effects of Inhalation Aerosols, Astra Pharmaceuticals, Lund, 1983, pp. 66–72.Google Scholar
  3. 3.
    P. R. Byron. Pharm. Tech. 11:42–56 (1987).Google Scholar
  4. 4.
    P. R. Byron. J. Pharm. Sci. 75:433–438 (1986).Google Scholar
  5. 5.
    A. J. Hickey and P. R. Byron. J. Pharm. Sci. 76:338–340 (1987).Google Scholar
  6. 6.
    S. P. Newman. In S. W. Clarke and D. Pavia (eds.), Aerosols and the Lung: Clinical and Experimental Aspects, Butterworths, London, 1984, pp. 197–224.Google Scholar
  7. 7.
    R. N. Dalby and P. R. Byron. Pharm. Res. 5:36–39 (1988).Google Scholar
  8. 8.
    A. J. Hickey, R. N. Dalby, and P. R. Byron. Int. J. Pharm. 40:267–270 (1988).Google Scholar
  9. 9.
    G. P. Polli, W. M. Grim, F. A. Bacher, and M. H. Yunker. J. Pharm. Sci. 58:484–486 (1969).Google Scholar
  10. 10.
    I. Gonda. Int. J. Pharm. 27:99–116 (1985).Google Scholar
  11. 11.
    N. Dombrowski and G. Munday. In N. Blakebrough (ed.), Biochemical and Biological Engineering Sciences, Academic Press, London, 1968, pp. 209–320.Google Scholar
  12. 12.
    W. R. Lane. Ind. Eng. Chem 43:1312–1317 (1951).Google Scholar
  13. 13.
    G. D. Gordon. J. Appl. Phys. 30:1759–1761 (1959).Google Scholar
  14. 14.
    L. J. Zajac. Droplet Breakup in Accelerating Gas Flows, NASA CR-134479, National Technical Information Service, Springfield, VA., 1973, pp. 1–59.Google Scholar
  15. 15.
    M. M. Clay, D. Pavia, S. P. Newman, and S. W. Clarke. Thorax 38:755–759 (1983).Google Scholar
  16. 16.
    C. V. Groom. Ph.D. thesis, University of Aston, Birmingham, U.K., 1981.Google Scholar
  17. 17.
    S. V. Hering, S. K. Friedlander, J. J. Collins, and L. W. Richards. Env. Sci. Tech. 13:184–188 (1979).Google Scholar
  18. 18.
    R. W. Rance. J. Soc. Cosmet. Chem. 25:545–561 (1974).Google Scholar
  19. 19.
    S. P. Newman, D. Pavia, F. Moren, N. F. Sheahan, and S. W. Clarke. Thorax 36:52–55 (1981).Google Scholar
  20. 20.
    P. Konig. Chest 88:276–284 (1985).Google Scholar

Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • Peter R. Byron
    • 1
    • 2
    • 3
  • Richard N. Dalby
    • 2
  • Anthony J. Hickey
    • 3
  1. 1.College of PharmacyUniversity of KentuckyLexington
  2. 2.Fisons plc., Pharmaceutical DivisionResearch and Development LaboratoriesLoughborough, LeicestershireU.K
  3. 3.College of Pharmacy (M/C 880)University of Illinois at ChicagoChicago

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