Effects of viscosity on power and hand injection of iso-osmolar iodinated contrast media through thin catheters

BACKGROUND

It can be challenging to achieve adequate vessel opacification during percutaneous coronary interventions when using thin catheters, hand injection, and iso-osmolar contrast media (CM) such as iodixanol (Visipaque™).

PURPOSE

To explore these limitations and the possibility to overcome them with iosimenol, a novel CM.

MATERIAL AND METHODS

Three X-ray contrast media with different concentrations were used in this study. A series of in vitro experiments established the relationship between injection pressure and flow rate in angiography catheters under various conditions. The experiments were conducted with power and hand injections and included a double-blind evaluation of user perception.

RESULTS

By using hand injection, it was generally not possible to reach a maximum injection pressure exceeding 50 psi. The time within which volunteers were able to complete the injections, the area under the pressure-time curve (AUC), and assessment of ease of injection all were in favor of iosimenol compared with iodixanol, especially when using the 4F thin catheter. Within the pressure ranges tested, the power injections demonstrated that the amount of iodine delivered at a fixed pressure was strongly related to viscosity but unrelated to iodine concentration.

CONCLUSION

There are substantial limitations to the amount of iodine that can be delivered through thin catheters by hand injection when iso-osmolar CM with high viscosity is used. The only viable solution, besides increasing the injection pressure, is to use a CM with lower viscosity, since the cost of increasing the concentration, in terms of increased viscosity and consequent reduction in flow, is too high. Iosimenol, an iso-osmolar CM with lower viscosity than iodixanol might therefore be a better alternative when thinner catheters are preferred, especially when the radial artery is used as the access site.

Intra-arterial and intravenous applications of Iosimenol 340 injection, a new non-ionic, dimeric, iso-osmolar radiographic contrast medium: phase 2 experience

BACKGROUND

Iosimenol 340 injection is a new, dimeric, iso-osmolar, iodinated contrast medium for X-ray angiography.

PURPOSE

To compare the safety and efficacy of iosimenol injection to iodixanol injection in two randomized, controlled phase 2 trials.

MATERIAL AND METHODS

One hundred and forty-four adult patients were enrolled in the two trials, one for evaluation during arteriography and the other for evaluation during computed tomography. Safety was compared by assessing adverse events, vital signs, ECGs, and laboratory parameters. Efficacy was assessed as X-ray attenuation in the computed tomography (CT) trial and as the quality of contrast enhancement in the arteriography trial.

RESULTS

There were no statistically significant differences in terms of safety or efficacy between the two contrast media. Both were well tolerated upon intravenous as well as intra-arterial injection. The most common adverse event was a feeling of warmth (observed in 35.1% of the patients with Iosimenol injection and 44.3% with iodixanol injection).

CONCLUSION

Iosimenol upon intravenous as well as upon intra-arterial injection exhibits a safety profile and shows an efficacy similar to that of iodixanol.

The pharmacokinetic profile, tolerability and safety of the iodinated, non-ionic, dimeric contrast medium Iosimenol 340 injection in healthy human subjects

Background

Iosimenol 340 injection is a new isotonic iodinated contrast medium for X-ray angiography.

Purpose

To investigate the pharmacokinetics and biotransformation, tolerability, and safety of Iosimenol 340 in healthy human subjects.

Material and Methods

Twenty-four subjects were enrolled and randomized to receive either Iosimenol 340 (0.5, 1.5 or 3.0 mL/kg) or placebo (0.9% saline). In each dosing group, six subjects received Iosimenol 340 and two subjects received placebo. Safety was assessed by physical examination, vital signs, electrocardiography, and laboratory tests. Adverse events were recorded throughout the study up to 14 days after dosing. Blood samples were collected from 10 min before until 48 h after the start of dosing and urine samples were collected from 15 min before until 96 h after the start of dosing. Iosimenol was quantified in plasma and urine by measuring iodine concentrations with X-ray fluorescence. High-performance liquid chromatography was used to assess iosimenol biotransformation.

Results

Mean half-lives (mean ± standard deviation [SD]) of iosimenol were 0.17 ± 0.08 h (10.2 ± 4.8 min) and 2.01 ± 0.32 h for distribution and terminal elimination phases, respectively. The apparent volume of distribution was 0.27 ± 0.05 L/kg, indicating distribution to the extracellular fluid volume. Iosimenol was excreted within 24 h without any sign of metabolic transformation. Thirty-two adverse events were observed in 14 subjects. All were mild or moderate, and were transient in nature.

Conclusion

Iosimenol was not metabolized, had a distribution volume corresponding to the extracellular space, and was rapidly excreted through the kidneys by glomerular filtration. The area under the plasma concentration curve and the peak plasma concentration was proportional to dose, while clearance was independent of dose. Iosimenol 340 was well tolerated.

Hemodialysis clearance of iosimenol, a novel iso-osmolar radiographic contrast medium

BACKGROUND

Iodinated contrast media (CM) have molecular and pharmacokinetic properties likely to make them highly dialyzable. Controlled clinical studies allowing for comparisons of hemodialysis clearance between different test substances and in multiple hemodialysis filters are, however, complex and not always practically feasible. A miniaturized in vitro method was therefore developed to evaluate the dialyzability of a new CM.

PURPOSE

To evaluate hemodialysis clearance of iosimenol, a novel iso-osmolar contrast medium (CM), in a select variety of hemodialysis filters and in comparison to commercially available CM.

MATERIAL AND METHODS

Three different high-flux and one low-flux membrane were used in miniaturized dialyzers to evaluate the in vitro blood clearance of iosimenol. Commercially available CM (iodixanol and iohexol) served as control substances. In vitro dialysis parameters were then used to predict clinical hemodialysis clearances. Residual ratios of endogenous substances (inorganic phosphate, urea nitrogen, creatinine, total bilirubin, and albumin) were used as proof of reliability of the in vitro dialysis system.

RESULTS

Dialyzable small endogenous molecules were readily eliminated in all membranes. The removal ratios of iosimenol were generally similar to that of iodixanol in all membranes except the high-flux polysulfone but were consistently lower than that of iohexol. The blood clearance of iosimenol during clinical hemodialysis was predicted as, on average, approximately 85 mL/min with the high-flux membranes and 47 mL/min with the low-flux membrane.

CONCLUSION

The dialyzability of iosimenol was evaluated using a newly developed in vitro dialysis system, and iosimenol was readily cleared from blood with all four tested membranes. And it is suggested that the dialysis parameters can predict clinical hemodialysis clearance of CM.

Electrocardiographic response to intravenous and intraarterial injection of iosimenol (a new, iodinated, non-ionic, iso-osmolar contrast medium)

Serious arrhythmias, sometimes related to the injection of iodinated contrast media, are known complications of cardiac angiography. A new, iodine-based, non-ionic, iso-osmolar x-ray contrast media is in development for use in these procedures. This contrast medium, iosimenol, has a lower viscosity, higher electrolyte content, and higher iodine concentration than other available iso-osmolar contrast media. The present study is a retrospective re-read and centralized analysis of the electrocardiographic response to intravenous and non-cardiac intraarterial injections of iosimenol, placebo, or iodixanol (Visipaque; GE Healthcare, Inc) in a total of 167 healthy subjects and patients enrolled in early clinical trials. No clinically relevant changes in heart rate and rhythm, morphology, atrioventricular conduction, or ventricular repolarization were noted after injection of any of the test articles in these studies. These results, despite the limited number of patients in these trials, suggest that iosimenol can be used safely in larger populations.