Journal of Materials Science

, Volume 37, Issue 17, pp 3595–3598 | Cite as

The determination of the critical stress intensity factor in mode II loading and the shear fracture strength of pharmaceutical powder specimens

  • F. Podczeck


The shear fracture strength and the critical stress intensity factor in mode II loading of lactose monohydrate and acetylsalicylic acid powder compacts has been evaluated. The experimental results of the shear fracture strength and the critical stress intensity factor in mode II loading appeared to be in good agreement with powder behaviour such as lamination and capping during compaction. Values for the critical stress intensity factor in mode II loading depended on the depth of the crack and hence, any reference of such values or their use to calculate a “fracture toughness ratio” (KICI/KICII) must refer to the notch depth applied. The results confirmed that the failure of such powder compacts occurs mainly in tension, but that lactose monohydrate has a tendency also to fail in shear. The latter does not apply to acetylsalicylic acid. Hence, lactose monohydrate should only be used cautiously in layer or press-coated tablets.


Powder Compact Fracture Toughness Lactose Stress Intensity Factor Lamination 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    P. STANLEY, Int. J. Pharm. 227 (2001) 27.PubMedGoogle Scholar
  2. 2.
    B. LAWN, “Fracture of Brittle Solids, ” 2nd edn. (Cambridge University Press, Cambridge, UK, 1993) p. 23.Google Scholar
  3. 3.
    F. PODCZECK, J. Mater. Sci. 36 (2001) 4687.Google Scholar
  4. 4.
    Idem., Int. J. Pharm. 227 (2001) 39.PubMedGoogle Scholar
  5. 5.
    M. L. DUNN, W. SUWITO, S. CUNNINGHAM and C. W. MAY, International Journal of Fracture 84 (1997) 367.Google Scholar
  6. 6.
    R. HILL, “The Mathematical Theory of Plasticity” (Claredon Press, Oxford, 1998) p. 325.Google Scholar
  7. 7.
    N. IOSIPESCU, J. Materials 2 (1967) 537.Google Scholar
  8. 8.
    A. SEERAT-UN-NABI and B. DERBY, J. Mater. Sci. Lett. 9 (1990) 63.Google Scholar
  9. 9.
    A. H. DE BOER, H. VROMANS, C. F. LERK, G. K. BOLHIUS and K. D. KUSSENDRAGER, Pharmaceutical Weekblad 8 (1986) 145.Google Scholar
  10. 10.
    H. CHAI, International Journal of Fracture 37 (1988) 137.Google Scholar
  11. 11.
    Idem., ibid. 58 (1992) 223.Google Scholar
  12. 12.
    M. FARSHAD and P. FLÜELER, Engineering Fracture Mechanics 60 (1998) 597.Google Scholar
  13. 13.
    R. RIKARDS, F.-G. BUCHHOLZ, H. WANG, A. K. BLEDZKI, A. KORJAKIN and H.-A. RICHARD, ibid. 61 (1998) 325.Google Scholar
  14. 14.
    K. L. JOHNSON, Proc. Roy. Soc. London A 453 (1997) 163.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • F. Podczeck
    • 1
  1. 1.The School of PharmacyUniversity of LondonLondonUK

Personalised recommendations