African Journal of
Pharmacy and Pharmacology

  • Abbreviation: Afr. J. Pharm. Pharmacol.
  • Language: English
  • ISSN: 1996-0816
  • DOI: 10.5897/AJPP
  • Start Year: 2007
  • Published Articles: 2084

Full Length Research Paper

A modified arithmetical method of Reed and Muench for determination of a relatively ideal median lethal dose (LD50)

Saganuwan Alhaji Saganuwan
Department of Veterinary Physiology, Pharmacology and Biochemistry, College of Veterinary Medicine, University of Agriculture, P. M. B. 2373, Makurdi, Benue State, Nigeria.
Email: [email protected]

  •  Accepted: 27 July 2011
  •  Published: 29 September 2011


Reed L.J. and Muench H. introduced arithmetical method for determination of median lethal dose (LD50) in 1938. Since then the same method has not been revised for better precision and accuracy. Therefore this paper examined the possibility of modifying the method and arrived at logical conclusion. The possible modifications involve calculating per cent of test animals both that died and survived at all the test dose levels. The average of a dose that caused 50% death and another dose that caused 50% survival gave a relatively ideal LD50. More so the difference between the dose that caused 50% death and 50% survival gave a dose which corresponded with a dose that killed one animal and the value was multiplied by 5 animals and then yielded anvalue that was close to the estimated LD50 confirming what should have been the ideal LD50.


Key words: Arithmetic, survival, death, average, median lethal dose.

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