DESCRIPTION

UNASYN (ampicillin and sulbactam) for injection, USP is a sterile antibacterial fixed-combination drug product consisting of the semisynthetic antibacterial ampicillin sodium and the beta-lactamase inhibitor sulbactam sodium for intravenous and intramuscular administration.

Ampicillin sodium is derived from the penicillin nucleus, 6-aminopenicillanic acid. Chemically, it is monosodium (2S, 5R, 6R)-6-[(R)-2-amino-2-phenylacetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate and has a molecular weight of 371.39. Its chemical formula is C16H18N3NaO4S. The structural formula is:

Sulbactam sodium is a derivative of the basic penicillin nucleus. Chemically, sulbactam sodium is sodium penicillinate sulfone; sodium (2S, 5R)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate 4,4-dioxide. Its chemical formula is C8H10NNaO5S with a molecular weight of 255.22. The structural formula is:

UNASYN is available as a white to off-white dry powder for reconstitution. UNASYN dry powder is freely soluble in aqueous diluents to yield pale yellow to yellow solutions containing ampicillin sodium and sulbactam sodium equivalent to 250 mg ampicillin per mL and 125 mg sulbactam per mL. The pH of the solutions is between 8.0 and 10.0.

Dilute solutions (up to 30 mg ampicillin and 15 mg sulbactam per mL) are essentially colorless to pale yellow. The pH of dilute solutions remains the same.

Each 1.5 g vial contains ampicillin 1 g and sulbactam 0.5 g (equivalent to 1.063 g ampicillin sodium and 0.547 g sulbactam sodium). Each 1.5 g vial contains approximately 115 mg of sodium.

Each 3 g vial contains ampicillin 2 g and sulbactam 1 g (equivalent to 2.125 g ampicillin sodium and 1.094 g sulbactam sodium). Each 3 g vial contains approximately 230 mg of sodium.