Absorption, Distribution and Excretion
A small amount of the drug can be absorbed via bladder instillation. After intrauterine instillation, most of the drug is expelled into the vagina immediately after the procedure. However, any drug remaining in the uterine or peritoneal cavity will be absorbed systemically within 60 minutes. If the fallopian tubes are blocked or dilated, absorption may not occur for up to 24 hours. Iohexol is absorbed into the bloodstream from cerebrospinal fluid (CSF) and excreted via the kidneys. No significant metabolism, deiodination, or biotransformation occurs. 350-849 mL/kg 109 mL/min [Adult patients receive 16-18 ml of iohexol (180 mgI/mL) via intrathecal injection in the lumbar spine] Biological Half-Life The intrathecal half-life is 3.4 hours (average). The intravascular half-life is approximately 2 hours (with normal renal function).

Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation
Limited information indicates that breast milk contains low levels of iohexol after a mother takes up to 45.3 grams (containing 21 grams of iodine). Furthermore, due to poor oral absorption of iohexol, it is unlikely to enter the infant's bloodstream and therefore will not have any adverse effects on breastfed infants. The manufacturer recommends discontinuing breastfeeding for 10 hours after administration to minimize infant exposure; however, guidelines from multiple professional organizations indicate that breastfeeding mothers do not need to interrupt breastfeeding after receiving iodine-containing contrast agents. ◉ Effects on Breastfed Infants
No published information found as of the revision date. ◉ Effects on Breastfeeding and Breast Milk
No published information 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 phthalamide compound with N-(2,3-dihydroxypropyl)carbamoyl groups at positions 1 and 3, iodine substituents at positions 2, 4, and 6, and an N-(2,3-dihydroxypropyl)acetamide group at position 5. It can be used as a radioactive contrast agent, an environmental pollutant, and an exogenous substance. It is an organic iodine compound and a phthalamide compound. Iohexol is an effective non-ionic, water-soluble contrast agent used for myelography, arthrography, renal angiography, arteriography, and other radiological examinations. Its low systemic toxicity is a result of both low chemical toxicity and low osmotic pressure. Iohexol is a radioactive contrast agent. Its mechanism of action is as an X-ray contrast agent. Iohexol is an X-ray contrast agent containing varying concentrations of iodine, ranging from 140 to 350 mg per milliliter.
It is an effective non-ionic, water-soluble contrast agent used for myelography, arthrography, renal angiography, arteriography, and other radiological examinations. Its low systemic toxicity is a result of both low chemical toxicity and low osmotic pressure.
Drug Indications

Iohexol is used for myelography, arthrography, renal angiography, arteriography, and other radiological examinations.
Mechanism of Action

Organic iodine compounds block X-rays as they pass through the body, thus creating a clear contrast between iodine-containing and non-iodine-containing surface structures. The degree of visualization produced by these compounds is proportional to the total amount (concentration and volume) of iodinated contrast agent in the X-ray path. Intrathecal injection into the subarachnoid space allows ioohexol to diffuse in the cerebrospinal fluid, visualizing the subarachnoid space of the head and spinal canals. Intravascular administration of ioohexol visualizes the flowing blood vessels, allowing observation of internal vascular structures until significant hemodilution occurs.

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Pharmacodynamics
Iohexol is an effective non-ionic, water-soluble contrast agent used for myelography, arthrography, renal angiography, arteriography, and other radiological examinations. Its low systemic toxicity is a result of the combined effects of low chemical toxicity and low osmotic pressure.

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.)