Difloxacin (hydrochloride)

Difloxacin hydrochloride (A-56619 hydrochloride) is an orally active bactericidal agent. Difloxacin hydrochloride inhibits bacterial DNA gyrase. Difloxacin hydrochloride exhibits concentration-dependent bactericidal activity. Difloxacin hydrochloride shows strong in vitro activity against a variety of Gram-positive and Gram-negative bacteria. Difloxacin hydrochloride can be used in research related to colibacillosis and *Staphylococcus aureus* infections^[1][2][3]. In Vitro:Difloxacin (24-48 h) hydrochloride inhibits and eliminates the field strain of E. coli O78 in vitro with an MIC of 0.02 µg/mL and an MBC of 0.04 µg/mL^[1].
Difloxacin (0.04-12.5 µg/mL) hydrochloride exhibits 3.99% protein binding in normal chicken serum in vitro^[1].
Difloxacin hydrochloride exhibits broad-spectrum in vitro antibacterial activity against clinical isolates of gram-positive (Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus faecalis) and gram-negative (Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, Proteus mirabilis, Proteus vulgaris, Serratia marcescens, Providencia stuartii, Pseudomonas aeruginosa) bacteria^[2].
Difloxacin (1-25 μg/mL; 72 h) hydrochloride dose-dependently and reversibly inhibits ConA-induced proliferation of human peripheral blood mononuclear cells, with maximum inhibition when added within the first 24 h of culture, 92% cell viability at 25 μg/mL, and no reversal of inhibition with increased mitogen concentration^[3]. In Vivo:The serum concentration of difloxacin (10 mg/kg; intravenous injection, oral administration; single dose) hydrochloride in healthy broilers remains sustainably above the MIC of E. coli, with an oral bioavailability as high as 86.2% and an elimination half-life of 3.7 h following intravenous injection^[1].
Difloxacin (administered via subcutaneous injection or oral route; twice daily; at 1 h and 5 h post-infection) hydrochloride exhibits an ED₅₀ of 1.7 mg/kg per day for subcutaneous administration and 3.2 mg/kg per day for oral administration against lethal *Staphylococcus aureus* 10649 infection in CF-1 mice^[2].