Used as an antibacterial agent in pharmaceutical formulations, particularly in topical or injectable preparations where improved solubility is required. The lactate salt form enhances water solubility compared to the base compound, allowing for better absorption and bioavailability in certain dosage forms. It is primarily employed in the treatment of bacterial infections, including urinary tract infections, respiratory infections, and other susceptible infections caused by sensitive microorganisms. Its application leverages the mechanism of inhibiting bacterial dihydrofolate reductase, disrupting folate synthesis essential for bacterial growth. Commonly found in combination with sulfonamides to achieve synergistic antibacterial effects.