Antimicrobial agents are substances that fight against infections caused by harmful microorganisms like bacteria, fungi, and viruses. Antimicrobial Drug Class includes various types of drugs used to treat different infections, depending on the pathogen involved. An example of a related chemical compound is Phthalic Anhydride, which is used in the production of plasticizers, resins, and other industrial chemicals, with potential antimicrobial properties in certain formulations.