Water-soluble antibacterial methampicillin lysine adducts - prepd. by reacting ampicillin with formaldehyde and lysine

摘要

New methampicillin-lysine adducts (methampicillin lysinate) are of formula (I): (where M is H or a metal e.g. Na, K, Ca or Al). (I) are active against Gram-positive and -negative bacteria. They have the advantage of water-solubility without loss of chemical stability. The water-solubility of (I) permits various liq. dosage forms to be formulated. (I) have very high absorption rates in the gastro-intestinal tract. In an example, methampicillin L-lysinate (i.e. (I; M = H) derived from L-lysine) is prepd. by adjusting an aq. suspension of ampicillin to pH 7-8 with NaHCO3, adding aq. formaldehyde, and L-lysine, and acidifying to pH 2.5-3.0 with HCl.