The metabolism of 5,5‘-methylenedisalicylic acid in various species

Abstract Commercial methylenedisalicylic acid has been shown to be grossly impure. Pure 5,5′-methylendisalicylic acid (4,4′-dihydroxydiphenylmethane-3,3′-dicarboxylic acid) has been prepared and labelled with 14C. The fate of the pure compound in the rat, mouse, hamster, rhesus monkey, rabbit, guinea-pig and chicken has been investigated. The compound is excreted entirely unchanged in the urine and faeces in all the above species and no metabolites have been found. The biliary excretion of the injected compound is high (50–60%) in the rat and dog and low (5%) in the guinea-pig and rabbit. In the monkey, rabbit and guinea-pig, the compound is excreted almost exclusively in the urine. In the rat about 50% of the dose is excreted in the faeces. In the mouse and hamster, the main route of excretion is the urine, about 10% appearing in the faeces.