1. The chlorofluorocarbon to hydrofluoroalkane transition: The effect on pressurized metered dose inhaler suspension stability 
Anne Brindley, BPharm, MRPharmS, PhD 
Journal of Allergy and Clinical Immunology 
Volume 104, Issue 6, Pages s221-s226 (December 1999)
DOI: /S (99)
Copyright © 1999 Mosby, Inc. Terms and Conditions

2. Fig. 1
The operation of a pMDI valve. (Adapted from Purewal TS. Formulation of metered dose inhalers. In: Purewal TS, Grant DJW, editors. Metered dose inhaler technology. Buffalo Grove, Ill.: Interpharm Press Inc, p © Interpharm Press Inc. Republished with permission.)
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

3. Fig. 2 An OSCAR technique set-up.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

4. Fig. 3
A, An example OSCAR profile for a stable creaming formulation. B, An example OSCAR profile for an unstable creaming formulation.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

5. Fig. 4 An OSCAR profile for a stable suspension.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

6. Fig. 5 An OSCAR profile for an unstable suspension.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

7. Fig. 6
Dose delivery data at different pause times between shaking and firing for stable suspension.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

8. Fig. 7
Dose delivery data at 0 pause time between shaking and firing for an unstable suspension.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions

9. Fig. 8
Dose delivery data at 5 minutes of pause time between shaking and firing for an unstable suspension.
Journal of Allergy and Clinical Immunology  , s221-s226DOI: ( /S (99) )
Copyright © 1999 Mosby, Inc. Terms and Conditions