Levofloxacin

Athanor · official

C₁₈H₂₀FN₃O₄ · 361.4 g/mol

IUPAC name: 7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo[7.3.1.05,13]trideca-5(13),6,8,11-tetraene-11-carboxylic acid

Also called Levaquin, fluoroquinolone

Drugs Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerHarmful if swallowed · Harmful in contact with skin · May cause an allergic skin reaction · Harmful if inhaled · May cause allergy or asthma symptoms or breathing difficulties if inhaled · Suspected of causing genetic defects · Suspected of damaging fertility or the unborn child

Names and identifiers

IUPAC name: 7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo[7.3.1.05,13]trideca-5(13),6,8,11-tetraene-11-carboxylic acid
Synonyms: Levaquin, fluoroquinolone, ofloxacin
+ 38 more
Floxin, Ofloxacine, Tarivid, Ocuflox, Ofloxacino, Visiren, Ofloxacinum, DL-8280, Ofloxacina, Exocin, Hoe-280, Floxin otic, Ofloxacin Otic, OFLX, HOE 280, FLOXIN IN DEXTROSE 5%, DTXSID3041085, DL 8280, CHEBI:7731, NSC-727071, NSC-758178, 7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo[7.3.1.05,13]trideca-5(13),6,8,11-tetraene-11-carboxylic acid, A4P49JAZ9H, FLOXIN IN DEXTROSE 5% IN PLASTIC CONTAINER, J01MA01, Hoe280, NSC727071, DTXCID1021085, DL8280, 8-Fluoro-3-methyl-9-(4-methyl-piperazin-1-yl)-6-oxo-2,3-dihydro-6H-1-oxa-3a-aza-phenalene-5-carboxylic acid, 9-FLUORO-2,3-DIHYDRO-3-METHYL-10-(4-METHYL-1-PIPERAZINYL)-7-OXO-7H-PYRIDO(1,2,3-DE)(1,4)BENZOXAZINE-6-CARBOXYLIC ACID, DL-, Ofloxaxin, Tarivid i.v., 7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo(7.3.1.05,13)trideca-5(13),6,8,11-tetraene-11-carboxylic acid, Ofloxacin Ophthalmic, Olfoxacin Otic Soln, Ofloxacin Ophth Soln, Tarivid 400
Molecular formula: C₁₈H₂₀FN₃O₄
Empirical formula: C₁₈H₂₀FN₃O₄
Molecular weight: 361.4 g/mol
Exact mass: 361.14378
CAS number: 100986-85-4
PubChem CID: 4583
Canonical SMILES: CC1COC2=C3N1C=C(C(=O)C3=CC(=C2N4CCN(CC4)C)F)C(=O)O
Isomeric SMILES: CC1COC2=C3N1C=C(C(=O)C3=CC(=C2N4CCN(CC4)C)F)C(=O)O
InChI: InChI=1S/C18H20FN3O4/c1-10-9-26-17-14-11(16(23)12(18(24)25)8-22(10)14)7-13(19)15(17)21-5-3-20(2)4-6-21/h7-8,10H,3-6,9H2,1-2H3,(H,24,25)
InChIKey: GSDSWSVVBLHKDQ-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

Appearance: Off-white to pale yellow crystalline powder[1]
Solubility in water: Soluble in aqueous solutions with pH between 2 and 5. Sparingly to slightly soluble in aqueous solutions with pH 7 (solubility falls to 4 mg/mL) and freely soluble in aqueous solutions with pH above 9.[1]
log P: log Kow = -0.39[1]
pKa: pKa1 = 5.97 (carboxylic acid)[1]
2 values
Only one source reports it.
Value As written Source
–shown pKa1 = 5.97 (carboxylic acid) [1] Hazardous Substances Data Bank (HSDB)cites Tolls J; Environ Sci Technol 35: 3397-406 (2001)
– pKa2 = 9.28 (piperizinyl ring) [1] Hazardous Substances Data Bank (HSDB)cites Tolls J; Environ Sci Technol 35: 3397-406 (2001)

Value	As written	Source
–shown	pKa1 = 5.97 (carboxylic acid)	[1] Hazardous Substances Data Bank (HSDB)cites Tolls J; Environ Sci Technol 35: 3397-406 (2001)
–	pKa2 = 9.28 (piperizinyl ring)	[1] Hazardous Substances Data Bank (HSDB)cites Tolls J; Environ Sci Technol 35: 3397-406 (2001)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 26
Rings: 4
Aromatic rings: 2
Fraction sp³ carbons (Fsp3): 0.44
H-bond donors: 1
H-bond acceptors: 5 computed here · PubChem 8
Rotatable bonds: 2
TPSA (Å²): 75 computed here · PubChem 73.3
Formal charge: 0
XLogP3: -0.4 PubChem
Complexity: 634 PubChem
Stereocenters: 0 defined, 1 undefinedCIP: C2: undefined
Double-bond geometry: None specified
Point group: C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C59.83%
H5.58%
F5.26%
N11.63%
O17.71%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: 1.54 Crippen (Wildman and Crippen 1999)
log S (water solubility): -3.21 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.1 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 361.37
log P ≤ 5 (Crippen): 1.54
H-bond donors ≤ 5: 1
H-bond acceptors ≤ 10: 5

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Most widely reported: 61 company reports to ECHA. Source [2].

Harmful or irritant
Health hazard

H302Harmful if swallowed (85.2% of reports)
H312Harmful in contact with skin (85.2% of reports)
H317May cause an allergic skin reaction (85.2% of reports)
H332Harmful if inhaled (85.2% of reports)
H334May cause allergy or asthma symptoms or breathing difficulties if inhaled (85.2% of reports)
H341Suspected of causing genetic defects
H361Suspected of damaging fertility or the unborn child (14.8% of reports)

Precautionary statements: P203, P233, P260, P261, P264, P270, P271, P272, P280, P284, P301+P317, P302+P352, P304+P340, P317, P318, P321, P330, P333+P317, P342+P316, P362+P364, P403, P405, P501

View all classifications (3)

[2] European Chemicals Agency (ECHA) · 61 reports · DangerH302, H312, H317, H332, H334, H341, H361
[2] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 23.1% (3 of 13) of reports.
[2] European Chemicals Agency (ECHA) · 13 reports · DangerH302, H315, H317, H319, H332, H334, H341, H361

Storage

Ofloxacin ophthalmic solution and otic solution should be stored at 15-30 °C.[1]
Store in tight, light-resistant container as defined in the usp-nf. This material should be handled and stored per label instructions to ensure product integrity.[1]

Safety data sheets on the supplier’s page: Fluorochem, Alfa Chemistry, Xianglong Pharmaceutical Standards (XL Standards).

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[2]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[3]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[4]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[5]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
[6]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.