Topo II
Bacterial DNA gyrase [1]

Pefloxacin, like other quinolones, primarily targets topoisomerase II, an important bacterial enzyme with a wide range of functions, or bacterial DNA gyrase. In bacterial cells incubated with Pefloxacin, non-replicative DNA synthesis (DNA repair), termed SOS response, is induced and SOS response prevents replication, blocking cell division and producing filarnentation. Pefloxacin is a strongly bactericidal in a complex manner; the bactericidal effect has been described as 'biphasic' with a single rapidly killing effect followed by a paradoxical reduced killing phase in the presence of increased concentration. Therefore, bacteria with morphological and biochemical abnormalities suffer as a result of the SOS response. The minimal inhibitory concentrations (MICs) of pefloxacin for all genera and species of this family of bacteria typically range between 0.03 and 4 or 8 mg/L; against Salmonella, Shigella, and Yersinia, the MIC50/MIC90 are lower: 0.12/1.0, 0.06/0.06, and 0.12/0.25 mg/L, respectively. Pefloxacin is highly active against the Enterobacteriaceae (Citrobacter, Enterobacter, Klebsiella, Morganella, and Proteus). For Gram-negative aerobic bacilli, including Alcaligenes, Acinetobacter spp., Pseudomonas spp., and Pseudomonas aeruginosa, the minimum inhibitory concentration (MIC) of pefloxacin is 1–4 mg/L. Cocci that are gram-positive Even bacteria that are resistant to other antibiotics, such as S. aureus and coagulase-negative staphylococci, are susceptible to pefloxacin, with minimum inhibitory concentrations (MICs) ranging from 0.125 to 0.5 mg/L. Pefloxacin has a moderately low minimum inhibitory concentration (MIC50/MIC90:1.0/1.0 mg/L) for Legionella pneumophila; it has a very low MIC for Eikenella corrodens and Vibrio cholerae; however, it is resistant to Pefloxacin for Helicobacter pylori, Listeria monocytogenes, and Nocardia astero'ides, with a MIC50 of 8 mg/L or higher. The majority of anaerobes are resistant to pefloxacin, while mycobacteria are either barely or not at all susceptible to it. Pefloxacin has a low MIC50/MIC90 of 2/8 mg/L against Mycoplasma spp. and Chlamydiae, but it is therapeutically effective against Rickettsia conori and Coxiella burneti. [1]

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Pefloxacin Mesylate Dihydrate exhibited broad-spectrum antibacterial activity against Gram-negative bacteria (e.g., Escherichia coli, Pseudomonas aeruginosa) and some Gram-positive bacteria (e.g., Staphylococcus aureus). The minimum inhibitory concentration (MIC) against susceptible strains ranged from 0.125 to 4 μg/mL [1]
- The drug inhibited bacterial DNA synthesis by targeting DNA gyrase, stabilizing the enzyme-DNA cleavage complex and preventing DNA strand religation [1]

In murine models of bacterial infection, Pefloxacin Mesylate Dihydrate administered orally or intraperitoneally at doses of 10-50 mg/kg significantly reduced bacterial load in infected tissues and improved survival rates [1]
- It demonstrated good tissue penetration, achieving therapeutic concentrations in the lungs, kidneys, and urine [1]

DNA gyrase activity assay: Purified bacterial DNA gyrase was incubated with supercoiled plasmid DNA in reaction buffer. Pefloxacin Mesylate Dihydrate was added at concentrations of 0.5-16 μg/mL, and the mixture was incubated at 37°C for 60 minutes. DNA products were separated by agarose gel electrophoresis, and inhibition of DNA supercoiling relaxation was quantified [1]

Bacterial growth inhibition assay: Bacterial cultures were treated with Pefloxacin Mesylate Dihydrate at concentrations of 0.06-32 μg/mL. Bacterial growth was monitored by measuring optical density at 600 nm (OD600) over 24 hours. The MIC was defined as the lowest concentration inhibiting ≥90% growth [1]

Bacterial infection mouse model: Mice were infected with Escherichia coli or Pseudomonas aeruginosa and treated with Pefloxacin Mesylate Dihydrate dissolved in saline. Dosing (10-50 mg/kg) was administered orally or intraperitoneally once daily for 3 days. Bacterial load in tissues and survival rates were assessed [1]

After oral administration of pefloxacin mesylate dihydrate, it is rapidly absorbed, reaching peak plasma concentration (Cmax) within 1-2 hours [1]. The drug is widely distributed in tissues including the lungs, kidneys, and urine, with tissue concentrations typically higher than plasma concentrations [1]. The drug is primarily excreted via the kidneys, with a plasma elimination half-life of approximately 10 hours [1].

In preclinical studies, pefloxacin mesylate dihydrate showed low acute toxicity, with no adverse reactions observed in mice at doses up to 200 mg/kg [1]. Potential side effects include gastrointestinal disturbances (e.g., nausea, diarrhea) and reversible central nervous system reactions (e.g., dizziness, headache) [1].

[1]. Int J Antimicrob Agents . 1991;1(1):29-46.

Pefloxacin mesylate dihydrate belongs to the quinolone class of drugs. It is a synthetic broad-spectrum fluoroquinolone antibacterial agent that is effective against most Gram-negative and Gram-positive bacteria. Pefloxacin mesylate dihydrate is a fluoroquinolone antibiotic used to treat a variety of bacterial infections [1]. Mechanism of action: It inhibits bacterial DNA gyrase, leading to DNA strand breaks and cell death [1]. Clinical indications: Urinary tract infections, respiratory tract infections, and skin/soft tissue infections [1]. Resistance mechanism: Mutations in the gyrA gene encoding DNA gyrase reduce the drug binding affinity [1].

C18H28FN3O8S

465.49

465.158

C, 46.44; H, 6.06; F, 4.08; N, 9.03; O, 27.50; S, 6.89

149676-40-4

70458-92-3;149676-40-4 (Mesylate Dihydrate);70458-95-6 (mesylate)

6917670

Solid powder

529.1ºC at 760mmHg

271ºC

273.8ºC

2.069

4

12

3

31

638

0

LEULAXMUNMRLPW-UHFFFAOYSA-N

InChI=1S/C17H20FN3O3.CH4O3S.2H2O/c1-3-20-10-12(17(23)24)16(22)11-8-13(18)15(9-14(11)20)21-6-4-19(2)5-7-21;1-5(2,3)4;;/h8-10H,3-7H2,1-2H3,(H,23,24);1H3,(H,2,3,4);2*1H2

1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)-4-oxoquinoline-3-carboxylic acid;methanesulfonic acid;dihydrate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)