Investigation of Methyl Pyridinium-2-aldoxime Salts

Methyl pyridinium-2-aldoxime iodide (2-PAM iodide) has been reported to be effective in preventing and overcoming the toxic effects in animals poisoned with organic phosphorus compounds that are inhibitors of the cholinesterase enzymes. In order to obtain greater water solubility of the oxime and to eliminate undesirable side effects due to the iodide ion, various salts were prepared. The iodide ion was replaced by inorganic and organic ions: chloride, nitrate, dihydrogen phosphate, hydrogen sulfate, acetate, lactate, fumarate, and tartrate. Methods of preparation and physical contents of the salts are presented. The water solubility of the majority of these salts was many times greater than that of the iodide. The rate at which the various salts reactivate inhibited cholinesterase and the acute toxicity to mice are of the same order as that of 2-PAM iodide. On the basis of stability, physical properties, and pharmacological action, the 2-PAM chloride salt should be the one of choice.