Ampicillin Dimer Disodium Salt is the anhydrous form of Ampicillin Dimer Disodium Salt Hydrate (A634390), which can be used to develop HPLC methods that detect compounds or impurities related to ampicillin in bulk drug. Ampicillin Dimer is a related compound of Ampicillin (A634300), a β-lactam antibiotic used for treating bacterial infection. Ampicillin interferes with cell wall synthesis in bacteria.