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Iohexol’s story stretches back to the rise of medical imaging in the late twentieth century. Before non-ionic contrast agents appeared, imaging often meant using high-osmolar ionic compounds that brought a lot of discomfort and unwanted reactions. Radiologists needed something safer and better tolerated, and that’s how iohexol caught my attention during my time in an academic radiology department. The compound first came to market in the early 1980s. Its structure balanced high water solubility with minimal toxicity, which stood out compared to almost everything available at the time. Over the decades, product refinements tracked the evolving needs of clinicians and researchers. By the 2000s, iohexol had become common in hospitals around the world, not just for imaging, but as an analytical standard and reagent, reflecting a trusted track record built on real clinical cases.
Iohexol offers a unique combination of properties critical for medical and analytical applications. With high aqueous solubility and neutral charge, it bolsters its compatibility with the human body. This sets iohexol apart from earlier ionic agents which often triggered adverse events, especially in sensitive patients. Many commercial names—Omnipaque standing out as the global flagship—can be found on pharmacy and laboratory shelves. In reagent-grade form, it appears as a white to off-white powder, dissolving fast without problematic residues. A wide range of concentrations—two to three hundred milligrams of iodine per milliliter, depending on the intended use—make it versatile. I remember working with technologists trying to match the right batch and labeling with patient and experiment need; with its clear standards, iohexol streamlined the workflow and prompted fewer mistakes.
A molecular formula of C19H26I3N3O9 and a molar mass over 800 grams per mole lend iohexol its unique radiopacity. The molecule packs three iodine atoms, so it shines on X-ray images and CT scans. At room temperature, iohexol appears solid and crystalline but dissolves completely in water to form clear, colorless solutions. It holds a nearly neutral pH in the range of 6.8 to 7.7, so living tissues tolerate it well. Its viscosity, lower than the old ionic agents, means reduced injection pressures and smoother delivery for both patients and laboratory equipment. Boiling and melting points don’t often factor in clinical use, but stability at room temperature simplifies storage and distribution.
Iohexol’s technical labels spell out specifics in detail—critical when matching reagent to application. Each bottle or vial includes information on iodine concentration, batch number, expiration date, and sterilization method. Quality control sheets report endotoxin and contamination checks, since even a trace of impurities can skew imaging or chemical assay results. Product labels include safety icons and detailed instructions for handling and reconstitution. In many institutions, digital inventory tracking now links each lot number to a patient or experiment dataset. Such traceability cuts down on error rates and supports data integrity during audits or publication review.
Manufacturing iohexol follows a stepwise synthetic pathway, starting from simpler iodinated aromatic compounds. Each stage adds functional groups through reactions like nitration, amidation, and etherification, finishing with purification steps that strip away side-products and contaminants. Modern production often uses continuous flow reactors to maintain consistent yields and tighter quality metrics. Once the bulk material reaches proper purity, technicians dissolve it in sterile water to create injectable or standard solutions. I once visited a manufacturing line where chemists obsessively monitored every parameter—temperature, pressure, pH—to ensure each lot met strict pharmacopoeial requirements. Such vigilance demonstrates the industry’s focus on minimizing risks for both patients and researchers.
Iohexol’s backbone favors chemical stability, making it less likely to degrade or interact unexpectedly during storage or use. The molecule does not easily undergo hydrolysis or oxidation in typical storage conditions. Analytical chemists sometimes derivatize iohexol for specialized detection or extraction methods, for example, tagging with radioisotopes or fluorescent markers. In my hands, iohexol proved robust in buffer solutions, with minimal signal loss during high-performance liquid chromatography, making it a dependable choice as an internal standard. Its structure reacts only under substantial energy input, so routine handling does not risk dangerous transformations or side-product formation.
Pharmacies and labs around the world encounter iohexol under names like Omnipaque (the market leader), Accupaque, and Exypaque. Chemical suppliers may list it as Iohexolum, 2,4,6-Triiodo-N,N′-bis(2,3-dihydroxypropyl)-5-(N-methylacetamido)-1,3-benzenedicarboxamide, or by registry numbers like CAS 66108-23-0. For those in research, it pays to double-check product codes before ordering; once, I received a mislabeled vial, and the batch number saved the day when I needed to troubleshoot. Application context often shapes which synonym gets used, but they all refer to this single, highly trusted molecule.
Hospitals, labs, and manufacturers all enforce strict safety protocols around iohexol. Technicians wear gloves and goggles to avoid skin and eye contact, as with any reagent, and follow spill-control procedures in case of accidental release. Iohexol’s low volatility and stable formulation lower the risk of inhalation exposure. Medical guidelines repeatedly emphasize slow injection and patient monitoring, since even rare allergic reactions can turn severe. Safety data sheets document all known hazards, including rare but serious responses like nephrotoxicity, especially in those with compromised kidney function. I have seen informed consent procedures and patient screening prevent more harm than any chemical property alone. Beyond patient care, transport and storage teams follow temperature and light protection rules, supporting long-term product integrity.
Iohexol now anchors diagnostic imaging, from standard CT scans to advanced angiography. Each radiologist I’ve spoken to values its clarity and consistency—arteries, tissues, and organs show up sharper, and patients recover faster post-procedure. Outside medicine, iohexol wins points as a marker in permeability and GFR studies, tracing kidney filtration in both clinical and research settings. Analytical chemists use it as a standard in chromatographic methods, especially where iodine’s detectability supports precision measurements. Water treatment and environmental labs occasionally rely on iohexol to simulate contaminant flow, since its movement mirrors real-world substances but with less ecological footprint.
The scientific landscape around iohexol is far from static. Ongoing projects test new formulations, including mini-dosed oral and intrathecal versions designed for special populations like infants and the elderly. Researchers explore analogs with tweaks toward faster elimination or even less immunogenicity. Big hospitals partner with tech firms to modernize automated dose-injection and tracking systems, shaving precious minutes off prep time and cutting down on error. I’ve watched university teams, funded by public grants, dissect the pharmacokinetics in diverse populations, aiming to close data gaps for groups historically underrepresented in clinical trials. That open sharing of methodologies and results pushes down barriers for newcomers in both diagnostics and basic research.
Iohexol boasts an impressive toxicity profile, but nothing is free from risk. Early trials showed clear improvement over prior agents, especially around cardiac and renal safety. That said, nephrotoxicity can still impact patients with pre-existing kidney impairment, so new protocols favor pre-screening and hydration before and after administration. Allergic-type reactions, ranging from simple rashes to severe anaphylaxis, do still occur, prompting new efforts in predictive screening and rapid response training. Animal models and cell studies continue, focusing on chronic exposure and very high-dose scenarios to map safety limits in lab and industrial contexts; these experiments offer reassurance, but they also remind everyone to respect even a reliable reagent.
Demand for non-ionic, low-toxicity imaging compounds shows no sign of fading. Next-generation diagnostic technologies require smarter, even safer reagents, and digital workflows need products with traceability and compatibility at the molecular level. Innovators test customized delivery systems—microspheres, gels, slow-release devices—hoping to make iohexol more accessible and useful beyond the CT suite. As imaging expands in developing countries, manufacturers and public health programs face the challenge of scaling up affordable, high-quality supply. Digital health records and “big data” analytics now draw on iohexol-enhanced images, so security and interoperability standards press new demands on suppliers. I see rich ground for collaboration between chemists, doctors, engineers, and informatics experts, each building on strong safety, clear labeling, and decades of real-world trust to shape the next stage of chemical reagent development.
Iohexol is often known as a contrast agent in radiology departments, but behind the scenes, it earns its stripes in research and clinical labs. The way scientists use iohexol goes beyond pictures on a monitor. It steps in when labs need a precise tool to measure how well our kidneys clear waste from the blood.
Back in my early biochemistry days, teachers drummed in that kidney health tells you a lot about the whole body. GFR is one of those gold-standard numbers doctors and researchers chase. Traditional tests like serum creatinine sometimes paint a fuzzy picture, especially in people with odd muscle mass or chronic illness. Iohexol gives a sharper image. It runs through the bloodstream, untouched and unbroken down, then the kidneys simply filter it out. By tracking its fate, the lab can pull a number that reflects kidney function in real-time.
Unlike older substances such as inulin, which require complex protocols and lots of patient cooperation, iohexol simplifies things. Give a dose, collect a few blood samples, and labs have what they need. Modern labs favor iohexol because high-performance liquid chromatography (HPLC) or mass spectrometry methods bring accuracy to the table without much hassle.
Our aging population and the global diabetes pandemic put kidney health under the microscope. Clinical trials and epidemiological studies depend on repeatable, unbiased data. Iohexol-based GFR testing becomes crucial here. With data in hand, policy makers can fine-tune public health strategies, and doctors can spot issues faster. Iohexol’s role in pinpointing damage early on means fewer surprises and better management of CKD.
Labs studying new kidney drugs in animals trust iohexol too. Its safety profile and consistent results grant it a spot in preclinical studies. In veterinary labs, cats and dogs facing chronic kidney issues now benefit from the same precision once reserved for people.
Safety always crops up whenever chemicals enter the scene. Iohexol is less likely to cause an allergic reaction or kidney harm compared to some other contrast agents. In the lab, using small doses lets technicians keep risks low for patients and lab workers. Still, waste management cannot take a back seat. Used contrast can pollute water sources. Responsible disposal and staff training keep the environmental impact in check.
Iohexol’s benefits sometimes get lost where resources run thin. In rural clinics and underfunded hospitals, the price of fancy analyzers can stall progress. Nonprofits and research partnerships can bridge the technology and training gap, making sure accurate kidney function testing reaches beyond big-city hospitals. Public sharing of protocols and open-access research go a long way, especially when experts from around the world compare data.
Iohexol shows how simple molecules can drive big changes in healthcare. Its story isn’t about glamorous technology; it’s about everyday people getting the right answer when it counts. Careful lab practices, ongoing education, and better logistics let iohexol do what it does best—deliver clear answers about kidney health.
Iohexol stands out on the pharmacy shelf not just for what it does, but what’s inside it. This isn’t just another chemical—this is a radiological tool packed with three iodine atoms arranged around a benzene ring. That iodine load matters. Hospitals depend on these atoms to help make blood vessels, organs, even problematic tumors pop on a CT scan. The way those iodine atoms anchor themselves to the structure lets iohexol do its job without crashing the kidneys every time.
Chemists see iohexol as a 2,4,6-triiodinated benzene ring. Each iodine grabs its own spot on the ring, with the rest packed with various side chains that manage water solubility, stability, and patient safety. There’s a pair of N-(2,3-dihydroxypropyl)carbamoyl groups and one N-(2-hydroxyethyl)carbamoyl group stuck on the other positions. Each of those odd-sounding attachments serves a purpose: breaking up water tension so the compound flows easily, and keeping the molecule from sticking to cell walls where nobody wants a dye stain.
The exact molecular formula looks like C19H26I3N3O9. A quick glance at that mix and someone can see heavy atomic weight, lots of oxygen for solubility, and nitrogen groups for safely slipping through the bloodstream. Water solubility remains a key point for any intravenous agent; no one wants particles clumping or clogging tiny blood vessels. That’s why pharmaceutical companies chased after non-ionic, low-osmolar agents like iohexol in the first place.
Looking at iohexol under the microscope tells a bigger story—one every patient getting a CT scan should know about. Chemical design reduces the risk of bad reactions. Iohexol avoids the charged particles and high-osmolar concentrations that led older dyes to trigger everything from hot flashes to severe kidney stress. Patients with weak kidneys, diabetes, or heart disease feel the benefits every day. Data show that non-ionic, low-osmolar contrast agents like iohexol cause far fewer cases of contrast-induced nephropathy than the old high-osmolar choices.
Every iodine atom in iohexol’s structure has a job: helping X-rays bounce, highlighting trouble. Too much iodine, or the wrong attachments, would mean higher viscosity, poor clearance, and bad outcomes. Iohexol’s scientists built it light enough to travel through narrow capillaries and stable enough not to fall apart in the bloodstream. Its elaborate architecture reflects decades of lessons—side effects, emergencies, recalls, and incremental breakthroughs.
Iohexol is good, but not perfect. Patients with severely compromised kidneys remain at risk for contrast-induced injury. Researchers explore new side chains, different functional groups, and alternative ring structures, looking for a blend of clarity, safety, and speed of clearance. Ongoing trials compare tweaks to chemical structure against actual health outcomes—trying to predict, and prevent, the rare, but life-changing, complications that still happen.
Iohexol’s chemical structure deserves attention not just from chemists, but from everyone involved in patient care. The lines drawn in the lab affect real families, every day. Each new improvement in design means one less reaction, one more safe scan, and—hopefully—less worry for those who need answers from their doctors and radiologists.
Keeping Iohexol in top condition isn’t just about following a checklist. It’s about ensuring that every patient scan brings clear results and no one’s health falls through the cracks. My first job in a hospital pharmacy brought that message home. I remember carting contrast agents to storage rooms. The rush between departments made temperature logs easy to overlook. But small missteps can wreck a vial’s usefulness and mean retesting a patient.
Temperature sets the bar for Iohexol. The manufacturer’s label usually recommends keeping the vials in a range of 15 to 30°C. Refrigerators seem like a safe bet in many hospital storage closets. Yet, with Iohexol, chilling a vial might cause crystallization. Once crystals show up, that vial can’t safely go into a patient’s veins. Shaking or reheating can’t undo the damage. A few degrees off for too long means tossing expensive product and disappointing both staff and patients.
From experience, most stock rooms play it safe by maintaining ambient temperature right between 20 and 25°C. This way, techs don’t risk either freezing or overheating. I’ve seen drug cabinets fitted with digital thermometers and alarms. When heat from nearby lights or equipment sneaks up, someone always catches it.
Leaving vials out in direct sunlight used to be rare. These days, even well-lit prep rooms pose a risk. Iohexol’s label warns against excess light. Fading labels or yellowing solutions hint that light exposure has changed something inside the vial. Clear containers seem innocent enough on a shelf, but UV rays slipping through windows will degrade sensitive compounds over time.
I used to think wipes and gloves were only about patient safety. Turns out, dusty vials invite contamination. Dust leads to mold spores and can even alter the reagent’s properties. Hospitals I worked in kept contrast agents shelved in clean, well-ventilated cabinets, not next to mop closets or maintenance rooms. Staff clean spills right away, since even small splashes cause labels to peel or let bacteria sneak under caps.
Accepting expired reagents just to save a few dollars undermines everyone’s effort. Iohexol comes stamped with a firm expiration date. Never trust cloudy or colored vials, no matter what the paperwork says. We learned the hard way that quick “visual inspections” at delivery didn’t catch everything. Setting up a rotation with fresh stock means old vials get used first. Techs in high-volume clinics keep logs for each vial. Even a week past the end date, reagents land in the waste bin, not on the CT table.
Sometimes, the best fix involves plain communication—pharmacy, imaging room, and receiving staff check storage spaces twice a week. Reports of temperature swings or power outages go straight to a supervisor. Anyone feeling tempted to bend the rules gets a reminder: one contaminated or degraded dose in the supply chain can derail a diagnostic process for a real person.
Iohexol isn’t just another chemical. It’s a lifeline for thousands of diagnostic scans every day. Hospitals and imaging centers juggle tight budgets, staff shortages, and equipment failures. Every good habit—temperature checks, daily shelf cleanings, prompt disposal—keeps patients safer and helps organizations keep their hard-earned reputations. Anyone in healthcare learns fast: reliable storage means confidence in the results and real trust from patients counting on answers.
Iohexol shows up in many chem labs, hospitals, and research centers. Anyone screening for kidney function or developing pharmaceuticals probably has seen it in the fridge. Iohexol’s main job happens in radiology as a contrast agent, but many analytical labs rely on it for reference standards and stability studies.
Many may ask, can you use iohexol with any instrument in the lab? Here’s where experience actually matters. Instruments are picky. They do not treat all chemicals the same. Iohexol’s molecular structure (C19H26I3N3O9) makes it highly water soluble and non-ionic, great for what radiologists need, but working with it on a range of analytical platforms presents both opportunities and limits.
I spent years working in clinical and analytical labs. Sometimes a new standard hits the bench, and the run to validation starts. Iohexol often passes the “dissolves in water” test. It looks like it should run through everything—HPLC, LC-MS, UV-Vis, maybe even GC. The truth is more complicated.
On HPLC, most teams find iohexol behaves nicely, especially with reverse-phase columns and aqueous buffers. Its robust solubility supports repeatable chromatograms. LC-MS users see another story. High iodine content can mess up ionization. The heavy atoms introduce ion suppression and, in some platforms, leave the spectra messy. Even seasoned analysts notice dramatic drops in sensitivity or signal noise.UV-Vis analysis benefits from iohexol’s clear absorbance bands, letting teams quantify with reasonable certainty. Ionic strength and possible matrix effects still lurk. Trying to use iohexol with GC usually ends badly. Iohexol decomposes at elevated temperatures, which means no reliable peaks appear and columns risk contamination.
Auto-samplers and injectors face another challenge. Iohexol’s high viscosity, even at standard concentrations, gums up some smaller bore systems. I have seen pipette tips clog and valve systems jam. Water-based mobile phases don’t always flush iohexol well, so residue cleanup becomes part of the routine.
Everything in an analysis depends on good data. Iohexol standards that fail to run cleanly waste time and risk batch rejection. Far worse, residues gumming up valves or sticking to inlets cost labs money, as maintenance escalates and downtime stretches out. In a busy clinical setting, that kind of glitch delays results for patients and eats at confidence.
The heavy atom effect in mass spectrometry deserves real attention. Iohexol’s iodine doesn’t just swamp the analyzer, it skews calibration and distorts internal standards. Teams using iohexol for pharmacokinetic work or biomarker validation often swap columns, adjust gradients, or rely on instruments with robust decontamination cycles. Sometimes a different contrast agent, such as iopamidol, gets the nod because it creates fewer artifacts.
Working with iohexol tests flexibility, not just compliance. Teams who screen methods up front, checking column compatibility and injection stability, dodge many of these headaches. Communication with service engineers, sharing chromatograms and spectra, keeps method development honest and maintenance cycles under control.
Some simple fixes pay dividends: using high-purity water with matched buffers, routinely cleaning all sample-contacting parts, setting up instrument-specific methods rather than one-size-fits-all. Training analytical staff on iohexol’s quirks ensures fewer late-night reruns and fewer critical errors.
Relying only on specs or vendor claims often lets problems slip through the cracks. Experience in the lab, handling iohexol alongside other common contrast agents, draws sharp lines between what works and what slows everything to a crawl. One right tool does not fit every job—and in analytical science, that lesson keeps echoing.
Iohexol earns a crucial spot in hospitals as a contrast agent for imaging. It helps radiologists spot what might otherwise hide on a scan. Despite its medical value, the compound deserves careful handling. Stories in clinical practice remind us that a busy hospital is no excuse for skipping safety steps. I’ve watched even seasoned techs skip gloves or overlook checking for leaks, and then pay the price with rashes or coughs a few hours later. Security for both patients and staff depends on consistent routines.
Gloves are the bare minimum. Impermeable ones stop splashes from reaching the skin. For syringes or vials, accidental drips can hit hands, wrists, and even forearms. So always grab a fresh pair. Goggles protect against a stray squirt, and lab coats or scrubs add another layer. I’ve seen how easy it is to forget goggles, and one eye splash can derail a shift. Respiratory masks don’t usually see much use, but a spill during reconstitution or transfer can put droplets in the air. Protection costs little compared to dealing with an exposure incident.
Keep any workspace for Iohexol clear of clutter and with proper air flow. A well-designed fume hood isn’t just overkill—it grabs and moves any airborne droplets or vapors out. Clinics and imaging rooms without specialized ventilation risk invisible buildup, especially in smaller spaces where repeated prep happens fast. Simple fixes like opening a window or running localized exhaust fans lower the stakes. Hospital rooms can be unpredictable, and it takes everyone’s diligence to keep these spaces safe.
Iohexol solutions belong in dedicated disposal containers after use. Regular bins aren’t built to contain contamination. Label them for hazardous pharmaceutical waste. If there’s a spill, act fast. Absorb the liquid using wipes or absorbent pads, then clean the surface with plenty of water. Dispose of everything in the labeled waste, not the general trash. Years in hospital environments show that staff training around spill kits and disposal makes a difference. A good habit here is reviewing the clinic’s spill protocol every few months.
Before giving Iohexol to a patient, two things matter most. Check for a history of allergic reactions and kidney problems. Allergic responses to contrast agents can rise out of nowhere, so stand ready with emergency supplies during administration. Monitoring doesn’t stop after the injection—patients sometimes react later. My time in imaging suites taught me that extra rounds with nurses after procedures pick up on those rare delayed reactions.
Medical staff see plenty of training mandates, but refresher courses on chemical handling don’t just tick boxes. They build a routine. Hands-on walk-throughs in real workspaces catch shortcuts or outdated habits before they become dangerous. New materials or changing protocols mean that what worked last year may not work now.
Iohexol has earned trust in medical imaging, but only through careful, methodical handling. Safety isn’t a one-time act; it runs on vigilance, readiness, and setting the expectation that every staff member respects these chemicals every time.
| Names | |
| Preferred IUPAC name | 5-((2,3-Dihydroxypropyl)amino)-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-1,3-benzenedicarboxamide |
| Other names |
Iohexolum Iohexol, solution iohexolo Iohexol-127I Omnipaque Omnipaque 240 Omnipaque 300 Omnipaque 350 |
| Pronunciation | /aɪˈhɛksɒl/ |
| Identifiers | |
| CAS Number | 66108-95-0 |
| 3D model (JSmol) | `3D model (JSmol)` string for Iohexol: ``` CC1(C(=O)N(C(=O)CN(C(=O)COC2C(C(C(C(O2)CO)O)O)O)C1(CI)I)CO)I ``` |
| Beilstein Reference | 4211062 |
| ChEBI | CHEBI:6015 |
| ChEMBL | CHEMBL1201201 |
| ChemSpider | 5590 |
| DrugBank | DB01362 |
| ECHA InfoCard | 03b33ae5-7e7d-4aa1-8911-bf92bbba6beb |
| EC Number | EC 259-912-1 |
| Gmelin Reference | 1166705 |
| KEGG | D08041 |
| MeSH | D007012 |
| PubChem CID | 3730 |
| RTECS number | TC9800000 |
| UNII | EC2JL3B0ZF |
| UN number | UN3248 |
| Properties | |
| Chemical formula | C19H26I3N3O9 |
| Molar mass | 821.13 g/mol |
| Appearance | White crystalline powder |
| Odor | Odorless |
| Density | 1.410 g/cm³ |
| Solubility in water | Very soluble in water |
| log P | -1.4 |
| Vapor pressure | <0.00001 hPa at 20 °C |
| Acidity (pKa) | pKa = 4.4 |
| Basicity (pKb) | pKb ~ 5.2 |
| Magnetic susceptibility (χ) | -11.0e-6 cm^3/mol |
| Refractive index (nD) | 1.450 |
| Viscosity | 10.4 to 15.1 cP |
| Dipole moment | 5.39 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 393.6 J·mol⁻¹·K⁻¹ |
| Pharmacology | |
| ATC code | V08AA01 |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes serious eye irritation. Causes skin irritation. May cause damage to organs through prolonged or repeated exposure. |
| GHS labelling | GHS07; GHS Signal Word: Warning; H317; H319 |
| Pictograms | GHS07, GHS08 |
| Signal word | Warning |
| Hazard statements | Hazard statements: Causes serious eye irritation. May cause respiratory irritation. |
| Precautionary statements | P261, P264, P271, P272, P273, P280, P302+P352, P305+P351+P338, P312, P337+P313, P362+P364, P501 |
| Lethal dose or concentration | LD50 (rat, oral): > 10,000 mg/kg |
| LD50 (median dose) | Intravenous LD50 (mouse): 22 g/kg |
| PEL (Permissible) | Not established |
| REL (Recommended) | REL (Recommended Exposure Limit) : Not established |
| IDLH (Immediate danger) | NIOSH has not established an IDLH value for Iohexol. |
| Related compounds | |
| Related compounds |
Iodixanol Iopamidol Iopromide Ioversol Iomeprol |
