Relationship between physicochemical properties of prussian blue and its efficacy as antidote against thallium poisoning.

In the present work we established a relationship between some physicochemical properties of two different batches of Prussian blue (PB) and their in vivo efficacy as an antidote against thallium poisoning. The physicochemical properties studied were crystallite size and thallium-adsorbing capacity. One of the batches was synthesized and the other was obtained from commercial sources. The synthesized PB batch with the smallest crystallite size had both the highest adsorption capacity and antidotal efficacy. Synthesized PB protected 100% of the animals against one LD50 thallium dose, whereas the commercial PB batch protected only 80%. Thallium content in blood and tissues (liver, kidney, brain) was also analysed after antidotal PB treatment in rats previously intoxicated with a sublethal dose of T1+. Animals treated with synthesized PB showed significantly less thallium in blood and tissue contents than those values of commercial PB-treated rats, indicating better antidotal properties of the synthesized PB. According to the present study we suggest an in vivo evaluation of the compound before distribution of the product to toxicological units, if X-ray diffractometric analysis is not available, in order to identify and determine the crystallite size of the compound as it plays an important role in the efficacy of PB.