LD50 is defined as the dose amount of poisonous, toxic substance or dose of ionizing radiation required to kill 50% of tested population. The classical LD50 test was introduced by Trevan (1992) and in this method; a large number of animals of more than 200 was used.
In OECD 1999 it is mentioned that “ there is strong scientific evidence that pain, distress, and suffering can exist in animals as in man”. It has grown concern about the use of laboratory animal assay in estimation of LD50, because in this case the methods can bring pain, distress and cause the animals to die slowly or in moribund condition. However this method is still needed to be performed in order to define the degree of hazard, find out susceptible population and target organs or system being exposed, archive clinical information about risk factor, diagnose and provide the treatment.
Animal welfare is dedicated to the three “R” Reduction, Refinement, and Replacement. As long as the laboratory animals can not be replaced, due to the need of information, it is utmost importance to reduce the number of animals to an absolute minimum without reducing information. The only way to obtain this aim is by using an optimal design. Bruce (1985, 1987) described about “ The up-and-down” method. This method can estimate the LD50 value and also reduce the number of animals used. In 2007 Tore Aune et all introduced a response surface design in estimation of LD50 marine biotoxins. This method can reduce the use of mice by 30%, if we compare with the plain design. The result obtained was compared and there was no significant different found.
We are very interested in developing this design and with my supervisor who has participated in that publication we would like to study the power and limitation of pathway response surface design, and the possibility to use this design in other fields of study.
In OECD 1999 it is mentioned that “ there is strong scientific evidence that pain, distress, and suffering can exist in animals as in man”. It has grown concern about the use of laboratory animal assay in estimation of LD50, because in this case the methods can bring pain, distress and cause the animals to die slowly or in moribund condition. However this method is still needed to be performed in order to define the degree of hazard, find out susceptible population and target organs or system being exposed, archive clinical information about risk factor, diagnose and provide the treatment.
Animal welfare is dedicated to the three “R” Reduction, Refinement, and Replacement. As long as the laboratory animals can not be replaced, due to the need of information, it is utmost importance to reduce the number of animals to an absolute minimum without reducing information. The only way to obtain this aim is by using an optimal design. Bruce (1985, 1987) described about “ The up-and-down” method. This method can estimate the LD50 value and also reduce the number of animals used. In 2007 Tore Aune et all introduced a response surface design in estimation of LD50 marine biotoxins. This method can reduce the use of mice by 30%, if we compare with the plain design. The result obtained was compared and there was no significant different found.
We are very interested in developing this design and with my supervisor who has participated in that publication we would like to study the power and limitation of pathway response surface design, and the possibility to use this design in other fields of study.
