Ampicillin (Sterile Ampicillin Sodium) is a white hygroscopic powder, which is freely soluble in water. It is an aminopenicillin with a broad spectrum of activity, especially against Gram-negative bacilli and Gram-positive bacteria as well, although generally less active. The chemical name of ampicillin is 4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid, 6-[(aminophenyl-acetyl) amino]-3, 3-dimethyl-7-oxo, [2S-{2-5-,B(S)}].