Is one paracetamol suppository of 1000 mg bioequivalent with two suppositories of 500 mg

  • T. Närvänen
  • M. Halsas
  • J. Smal
  • M. Marvola


A common belief is that one tablet or suppository containing, e.g. 100 mg of a drug can be substituted, without any changes in the therapeutic effect, with two units of the same brand containing 50 mg of the drug. In the present study a single dose of paracetamol was administered to healthy volunteers as (a) two tablets of 500 mg, (b) two suppositories of 500 mg, and (c) one suppository of 1000 mg. There were statistically significant differences in all bioavailability parameters (tmax, Cmax and AUC) between the three treatments. The relative bioavailability of the 500 mg suppositories was 77% and that of the 1000 mg suppositories 66%. The absorption rate from suppositories was markedly lower than from the tablets. Especially low absorption rate was obtained with the suppository of 1000 mg. The two strengths, although having the same trade name, were not therefore bioequivalent.


Paracetamol suppository rectal administration bioavailability bioequivalence 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Shim, C.K., Jung, B.H. (1992): Inter- and intrasubject variations of multiple saliva peaks of acetaminophen after oral administration of tablets. Int. J. Pharm., 82, 233–237.CrossRefGoogle Scholar
  2. 2.
    Shah, V. P., Midha, K.K., Dighe, S., McGilvery, I.J., Skelly, J.P., Yacobi, A., Layloft, T., Viswanathan, C.T., Cook, C.E., McDowall, R.D., Pittman, K.A., Spector, S. (1992): Analytical methods validation; bioavailability, bioequivalence and pharmacokinetic studies. J. Pharm. Sci. 81, 309–312.CrossRefGoogle Scholar
  3. 3.
    Adithan, C., Thangam, J. (1982): A comparative study of saliva and serum paracetamol levels using a simple spectrophotometric method. Br. J. Clin. Pharmacol. 14, 107–109.PubMedGoogle Scholar
  4. 4.
    Moolenaar, F., Olthof, L., Huizinga, T. (1979): Absorption rate and bioavailability of paracetamol from rectal aqueous suspensions. Pharm. Weekblad. Sci. Ed. 1, 25–30.Google Scholar
  5. 5.
    Seideman, P., Alvn, G., Andrews, R., Labross, A. (1980): Relative bioavailability of a paracetamol suppository. Eur. J. Clin. Pharmacol. 17, 465–468.CrossRefPubMedGoogle Scholar
  6. 6.
    Eandi, M., Viano, I., Ricci Gamalero, S. (1984): Absolute bioavailability of paracetamol after oral and rectal administration in healthy volunteers. Arzneim. Forsch. 43, 903–907.Google Scholar
  7. 7.
    Blume, H., Ali, S.L., Elze, M., Krämer, J., Wendt, G., Scholz, M.E. (1994): Relative bioverfügbarkeit von paracetamol in suppositorien-zubereitungen im vergleich zu tabletten. Arzneim. Forsch. 44, 1333–138.Google Scholar
  8. 8.
    Knoben, J.E., Anderson, P.O. (1993): Handbook of clinical drug data. 7th ed. Hamilton: Drug intelligence publication, p. 602.Google Scholar
  9. 9.
    Ström, C., Forsberg, O., Quiding, H., Engevall, S., Larsson, O. (1990): Analgesic efficacy of acetaminophen sustained release. J. Clin. Pharmacol. 30, 654–659.PubMedGoogle Scholar
  10. 10.
    Gjellan, K., Graffner, C., Quiding, H. (1994: Influence of amount of hard fat in suppositories on the in vitro release rate and bioavailability of paracetamol and codeine. I. A comparison of three suppository compositions in vivo. Int. J. Pharm. 102, 71–80.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1998

Authors and Affiliations

  • T. Närvänen
    • 1
  • M. Halsas
    • 1
  • J. Smal
    • 1
  • M. Marvola
    • 1
  1. 1.Division of Biopharmaceutics and Pharmacokinetics, Department of PharmacyUniversity of HelsinkiFinland

Personalised recommendations