Tuesday, January 8, 2013

Dose-Response Relationship (ED50 and LD50 Study)


This study or experiment investigates the Dose-Response relationship, focusing on the Effective Dose (ED50) and Lethal Dose (LD50) from toxicology point of view. The major aim of this experiment is to gain knowledge on how to estimate the effective dose that will be done by in vivo toxicity testing. Secondly is to determine the effective dose (ED50). Thirdly is to gain knowledge on how dose toxic effect will be obtained by in vivo toxicity testing and finally, to determine the median lethal dose (LD50). Approach that was used was by injecting a certain type of drug intra-peritoneally to a number of test animals which for this particular experiment are either rats or mice used and after that, the effect was observed. The result obtained is assessed based on the Reed-Muench Method (1938). The result obtained was, for ED50 was 20mg/kg while LD50 was 120 mg/kg meaning that at 20 mg/kg, 50% of a group of test animals exposed to the drugs was affected and also at 120mg/kg cause the death of 50% of a group of test animal. Therefore the aim which was to estimate the effective dose and lethal dose was achieved.

In the field of toxicology, the most essential concept is the dose-response relationship. Generally, it shows direct proportion between the dose and the response whereby increase dosage will cause increase effect and vice versa. From practical point of view, two types of dose-response relationships exist. First and foremost is the individual/graded dose-response relationship, also recognized as the response of individual organism to varying doses of chemical or graded due to the fact that the measured effect is continuous over a range of doses. Secondly, acid or sodium salt. The free acid is a fine white crystalline powder that is only slightly soluble in water and ethanol. The salt is a white crystalline powder or granules and is very soluble in water and ethanol. Pentobarbital is a popular short-acting barbiturate derivative used primarily as a sedative. It is also used to reduce intracranial pressure and lower cerebral oxygen demand in patients with severe head trauma, Reye’s syndrome, or anoxic brain damage. It is available alone or with other drugs in 15-200 mg amounts for oral, intramuscular or rectal administration. (Baselt et al.1982)