Bacampicillin (INN) is a penicillin antibiotic. It is a prodrug of ampicillin with improved oral bioavailability. Bacampicillin (INN) is a penicillin antibiotic. It is a prodrug of ampicillin with improved oral bioavailability. It is sold under the brand names Spectrobid (Pfizer) and Penglobe (AstraZeneca).