Absorption, Distribution and Excretion
Small amounts are absorbed through the bladder via intravesical instillation. Following intrauterine instillation, the majority of the medium within the uterine cavity is discharged into the vagina immediately upon termination of procedure. However, any medium retained in the uterine or peritoneal cavity is absorbed systemically within 60 minutes. May not be absorbed for up to 24 hours if tubes are obstructed and dilated.
Iohexol is absorbed from cerebrospinal fluid (CSF) into the bloodstream and is eliminated by renal excretion. No significant metabolism, deiodination, or biotransformation occurs.
350-849 mL/kg
109 mL/min [Adult patients receiving 16-18 ml of iohexol (180 mgI/mL) by lumbar intrathecal injection]

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Biological Half-Life
Intrathecal half-life is 3.4 hours (mean). Intravascular is approximately 2 hours (with normal renal function).

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Limited information indicates that maternal doses of iohexol up to 45.3 grams (containing 21 grams of iodine) produce low levels in milk. In addition, because iohexol is poorly absorbed orally, it is not likely to reach the bloodstream of the infant or cause any adverse effects in breastfed infants. The manufacturer states that withholding breastfeeding for 10 hours after administration to minimize the exposure of the infant; however, guidelines developed by several professional organizations state that breastfeeding need not be disrupted after a nursing mother receives an iodine-containing contrast medium.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

[1]. Development and validation of an HPLC-UV method for determination of iohexol in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Feb 25;816(1-2):339-43.

[2]. Hainfeld JF, Ridwan SM, Stanishevskiy Y, Smilowitz NR, Davis J, Smilowitz HM. Small, Long Blood Half-Life Iodine Nanoparticle for Vascular and Tumor Imaging. Sci Rep. 2018 Sep 14;8(1):13803.

[3]. The effects of the iodinated X-ray contrast media iodixanol, iohexol, iopromide, and ioversol on the rat kidney epithelial cell line NRK 52-E. Ren Fail. 2011;33(4):426-33.

[4]. Estimation of intestinal permeability in healthy dogs using the contrast medium iohexol. Vet Clin Pathol. 2009 Sep;38(3):353-60.

[5]. Population Pharmacokinetic Model of Iohexol in Dogs to Estimate Glomerular Filtration Rate and Optimize Sampling Time. Front Pharmacol. 2021 Apr 29;12:634404.

Iohexol is a benzenedicarboxamide compound having N-(2,3-dihydroxypropyl)carbamoyl groups at the 1- and 3-positions, iodo substituents at the 2-, 4- and 6-positions and an N-(2,3-dihydroxypropyl)acetamido group at the 5-position. It has a role as a radioopaque medium, an environmental contaminant and a xenobiotic. It is an organoiodine compound and a benzenedicarboxamide.
Iohexol is an effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.
Iohexol is a Radiographic Contrast Agent. The mechanism of action of iohexol is as a X-Ray Contrast Activity.
Iohexol is an X-ray contrast medium containing iohexol in various concentrations, from 140 to 350 milligrams of iodine per milliliter.
An effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.

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Drug Indication
Iohexol ia used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures.

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Mechanism of Action
Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. After intrathecal administration into the subarachnoid space, diffusion of iohexol in the CSF allows the visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, iohexol makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs.

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Pharmacodynamics
Iohexol is an effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.

C19H26I3N3O9

821.1379

820.88

66108-95-0

Iohexol-d5;928623-33-0

3730

White to off-white solid powder

2.2±0.1 g/cm3

891.5±65.0 °C at 760 mmHg

254-2560C

493.0±34.3 °C

0.0±0.3 mmHg at 25°C

1.724

-4.16

8

9

12

34

653

0

NTHXOOBQLCIOLC-UHFFFAOYSA-N

InChI=1S/C19H26I3N3O9/c1-8(29)25(4-11(32)7-28)17-15(21)12(18(33)23-2-9(30)5-26)14(20)13(16(17)22)19(34)24-3-10(31)6-27/h9-11,26-28,30-32H,2-7H2,1H3,(H,23,33)(H,24,34)

5-[acetyl(2,3-dihydroxypropyl)amino]-1-N,3-N-bis(2,3-dihydroxypropyl)-2,4,6-triiodobenzene-1,3-dicarboxamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

DMSO : ~50 mg/mL (~60.89 mM)
H2O : ≥ 50 mg/mL (~60.89 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (3.04 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (3.04 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (3.04 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 120 mg/mL (146.14 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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