CLINICAL TRIALS PROFILE FOR CITRIC ACID; UREA C-13

505(b)(2) Clinical Trials for Citric Acid; Urea C-13

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
New Dosage	NCT01533090 ↗	Evaluation of Reduced-volume PEG Bowel Preparation Administered the Same Day of Colonoscopy	Completed	Catholic University of the Sacred Heart	N/A	2010-04-01	The conventional total dose of 4 L of polyethylene glycol (PEG) given the day before the procedure is safe and effective. It has been the standard cleansing regimen for the last 25 years. To overcome the difficulty in completing the bowel preparation due to large volume and/or taste, reduced-volume (mixed) bowel preparation of bisacodyl and 2 L of PEG have been shown to provide adequate colon cleansing and better tolerability. LoVol-esse is a reduced-volume PEG-based bowel preparation to be used in combination with bisacodyl and designed to improve patient tolerability and attitude toward bowel cleansing prior to colonoscopy thanks to the reduced volume and improved taste. The present study is intended to compare the new dosing regimen of the bowel lavage solution given the same day compared with standard PEG formulation (SELG 1000) given the day before colonoscopy.

All Clinical Trials for Citric Acid; Urea C-13

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00260143 ↗	Testosterone and Physical Function in HIV+ Men	Completed	Charles Drew University of Medicine and Science	Phase 2	2003-05-01	Men infected with the HIV virus (the virus that causes AIDS) often lose weight even though they may try to eat more food to gain weight. The reasons for this weight loss are not clear. Many men with HIV have low levels of testosterone in their blood. Testosterone is a hormone that is naturally produced in the bodies of both men and women and has important effects on building muscle and bone mass. The purpose of this study is to find out if providing additional testosterone to HIV infected men who have low testosterone can help them gain weight, increase their muscle mass, and feel better. The study will also help see if testosterone improves the efficiency with which your body produces and uses energy including fat. The dose of testosterone being used in this study will raise testosterone levels in the blood to higher than normal levels (2-3 times normal level).
NCT00260143 ↗	Testosterone and Physical Function in HIV+ Men	Completed	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Phase 2	2003-05-01	Men infected with the HIV virus (the virus that causes AIDS) often lose weight even though they may try to eat more food to gain weight. The reasons for this weight loss are not clear. Many men with HIV have low levels of testosterone in their blood. Testosterone is a hormone that is naturally produced in the bodies of both men and women and has important effects on building muscle and bone mass. The purpose of this study is to find out if providing additional testosterone to HIV infected men who have low testosterone can help them gain weight, increase their muscle mass, and feel better. The study will also help see if testosterone improves the efficiency with which your body produces and uses energy including fat. The dose of testosterone being used in this study will raise testosterone levels in the blood to higher than normal levels (2-3 times normal level).
NCT00466154 ↗	The Effect of Serum LDL Lowering on Aspirin Resistance	Completed	Ziv Hospital	N/A	2005-07-01	Aspirin resistance is the persistent platelet activation, demonstrated by platelet function tests (1). The hypothesis is that:LDL lowering by statin in patients with aspirin resistance can improve the effect of aspirin due to the potential decreasing of cholesterol content in the platelet membranes. Patients and methods:Forty hypercholesterolemic patients with aspirin resistance after 5 days of treatment with aspirin and high LDL and triglycerides
NCT00547846 ↗	A Phase II Clinical Study of PDC-748 in Patients With Acute Cough	Completed	PhytoHealth Corporation	Phase 2	2007-10-01	The pharmacological effects of PDC-748 were tested in numerous in vitro and in vivo studies. The existing pharmacologic findings suggest that PDC-748 possesses certain inhibitory activity to the citric acid- and capsaicin-induced cough reflex in guinea pigs with a dose-dependent manner. Furthermore, a previous Phase I/II uncontrolled, dose-escalating study has shown PDC-748 to be well tolerated and may help to alleviate daytime cough with a dose-responding manner.Hence, PhytoHealth Corporation intends to carry out a Phase II investigation to confirm the preliminary findings using placebo in the comparator group, and to further investigate PDC-748 with a dose escalating manner to establish the dose-response range for its antitussive effect, and if possible, to determine the maximal tolerable dose of PDC-748. This is a randomized, double-blind, placebo-controlled, dose escalating study to evaluate the safety and efficacy of the escalating dose levels of PDC-748 in patients with acute cough.
NCT00583765 ↗	Evaluation of a Simplified Protocol for Regional Citrate Anticoagulation in Continuous Venovenous Hemodiafiltration	Completed	Gambro Renal Products, Inc.		2005-04-01	Dialysis requires thinning of the blood to prevent clotting in the dialysis machine. Thinning of the blood is necessary but some forms of blood thinners may cause bleeding. Therefore, researchers are seeking ways to minimize bleeding risks and ensure effective dialysis. One medication used to thin the blood in the dialysis machine is citrate. Citrate has the advantage of having its blood-thinning properties quickly reversed by calcium in the patient's blood. As a consequence, only the blood in the machine is thinned, greatly reducing the risk of bleeding when dialysis is carried out using other blood thinners. Until now, most patients who received citrate for dialysis were administered the citrate in a separate infusion through an IV pump into the dialysis machine. This method requires complex monitoring and calculations. This study is about Prismocitrate which is a dialysis fluid very similar to the regular dialysis fluid that is used in this intensive care unit, except that this fluid already contains exactly the correct amount of citrate. Thus, this method does not require a separate pump for citrate and calculations to pump the citrate into the blood as it goes through the kidney machine. Having the citrate already contained in the dialysis fluid simplifies the procedure and reduces the possibility of calculation errors. This study seeks to determine if this simplified means of providing blood thinning in the kidney machine also results in the correct balance of blood salts.
NCT00583765 ↗	Evaluation of a Simplified Protocol for Regional Citrate Anticoagulation in Continuous Venovenous Hemodiafiltration	Completed	University of Alberta		2005-04-01	Dialysis requires thinning of the blood to prevent clotting in the dialysis machine. Thinning of the blood is necessary but some forms of blood thinners may cause bleeding. Therefore, researchers are seeking ways to minimize bleeding risks and ensure effective dialysis. One medication used to thin the blood in the dialysis machine is citrate. Citrate has the advantage of having its blood-thinning properties quickly reversed by calcium in the patient's blood. As a consequence, only the blood in the machine is thinned, greatly reducing the risk of bleeding when dialysis is carried out using other blood thinners. Until now, most patients who received citrate for dialysis were administered the citrate in a separate infusion through an IV pump into the dialysis machine. This method requires complex monitoring and calculations. This study is about Prismocitrate which is a dialysis fluid very similar to the regular dialysis fluid that is used in this intensive care unit, except that this fluid already contains exactly the correct amount of citrate. Thus, this method does not require a separate pump for citrate and calculations to pump the citrate into the blood as it goes through the kidney machine. Having the citrate already contained in the dialysis fluid simplifies the procedure and reduces the possibility of calculation errors. This study seeks to determine if this simplified means of providing blood thinning in the kidney machine also results in the correct balance of blood salts.

Clinical Trial Conditions for Citric Acid; Urea C-13

Condition Name

Condition Name for Citric Acid; Urea C-13
Intervention	Trials
Xerostomia	4
Cough	3
Bowel Preparation	3
Helicobacter Pylori Infection	3

Condition MeSH

Condition MeSH for Citric Acid; Urea C-13
Intervention	Trials
Cough	6
Xerostomia	5
Glycogen Storage Disease	3
Motion Sickness	2

Clinical Trial Locations for Citric Acid; Urea C-13

Trials by Country

Trials by Country for Citric Acid; Urea C-13
Location	Trials
United States	48
United Kingdom	7
Egypt	5
Israel	5
Spain	5

Trials by US State

Trials by US State for Citric Acid; Urea C-13
Location	Trials
Texas	6
California	5
New York	4
Connecticut	3
Ohio	3

Clinical Trial Progress for Citric Acid; Urea C-13

Clinical Trial Phase

Clinical Trial Phase for Citric Acid; Urea C-13
Clinical Trial Phase	Trials
PHASE4	3
PHASE2	2
PHASE1	5

Clinical Trial Status

Clinical Trial Status for Citric Acid; Urea C-13
Clinical Trial Phase	Trials
Completed	43
RECRUITING	8
Not yet recruiting	7

Clinical Trial Sponsors for Citric Acid; Urea C-13

Sponsor Name

Sponsor Name for Citric Acid; Urea C-13
Sponsor	Trials
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	4
Repurposed Therapeutics, Inc.	3
University of Texas Southwestern Medical Center	3

Sponsor Type

Sponsor Type for Citric Acid; Urea C-13
Sponsor	Trials
Other	93
Industry	30
NIH	7

Citric Acid; Urea C-13: Clinical Trials Update and Market Analysis With Projections

Last updated: April 26, 2026

What is citric acid; urea C-13 and what are the commercial use-cases?

Citric Acid; Urea C-13 is a diagnostic tracer combination used in urea breath testing (UBT) systems to assess Helicobacter pylori status. UBT measures urease activity after oral administration of a labeled urea substrate (here, ^13C-urea) with downstream detection of ^13CO2 in exhaled breath. Citric acid is used as a formulation component that supports the test preparation and delivery of the labeled substrate.

This product class competes in the diagnostic testing workflow for H. pylori, where providers evaluate:

• Access to test consumables (labeled substrate kits)
• Breath collection and analytics workflow (instrumentation compatibility where applicable)
• Throughput and patient preparation requirements
• Regulatory status and reimbursement coverage by geography

What is the clinical trials landscape for citric acid; urea C-13?

No complete, reliable set of public clinical trial records could be compiled in a way that supports a complete and accurate “clinical trials update” for this specific combination across major registries (e.g., ClinicalTrials.gov, EU CTR, WHO ICTRP) within the constraints of this response format.

What does the market look like for H. pylori diagnostic UBT using ^13C-labeled urea?

The relevant market is H. pylori diagnostic testing, with urea breath tests as a core noninvasive option. UBT is used for:

• Primary diagnosis in symptomatic or pre-treatment settings where appropriate
• Test-of-cure after eradication therapy
• Post-treatment confirmation to reduce false negatives relative to some alternatives

Market structure

Demand drivers

• Ongoing H. pylori prevalence in key geographies
• Use of test-of-cure strategies in clinical guidelines
• Uptake of noninvasive diagnostics versus endoscopy-based approaches

Customer segments

• Hospitals and ambulatory clinics
• Specialty gastroenterology practices
• Diagnostic labs and managed care networks using centralized testing
• Home/point-of-care pathways where available (limited by local reimbursement and logistics)

Procurement pattern

• Mix of “kit” consumption and (in some workflows) instrument utilization
• Multi-year contracting for supply continuity where large health systems standardize test platforms

Competitive set (product categories that benchmark this combination)

This combination competes with:

• Other ^13C-urea breath test formulations (different kit formulations and citric acid blends, where used)
• ^14C urea breath tests (jurisdiction dependent; lower regulatory friction in some regions, more constrained in others)
• Non-UBT diagnostics: stool antigen tests, serology (less used for test-of-cure), and endoscopy with biopsy-based tests

Economic model

UBT economics typically scale with:

• Patient volume and test-of-cure compliance
• Reimbursement rates and diagnostic pathway rules
• Operational efficiency (collection time, kit handling, and analytics throughput)
• Avoided downstream costs from correct eradication verification

Because citric acid; urea C-13 sits in a standardized workflow, pricing power depends on distribution footprint, platform compatibility, and reimbursement coverage rather than differentiation of clinical performance alone.

How big is the addressable market and what is the projection method?

A complete market sizing and projection requires hard baselines (current unit volume and reimbursement-adjusted revenue) and a way to attribute share to ^13C-UBT versus other modalities. Those inputs are not present in the source material available here in a way that supports an accurate numeric projection for this exact combination.

Given that limitation, the only defensible “projection” available within this response structure is a scenario framework describing drivers of growth rather than a numeric forecast.

Projection framework for citric acid; urea C-13 (directional)

Base case growth drivers

• Increased test-of-cure adherence after eradication regimens
• Continued substitution toward noninvasive confirmation when guideline-driven
• Competitive procurement based on price per test and workflow throughput

Upside drivers

• Expanded outpatient and clinic-based UBT adoption
• Platform standardization where instrument networks already exist
• Improved patient adherence and reduced collection burdens with kit formats

Downside drivers

• Reimbursement compression
• Shift to stool antigen or other modalities in certain payor policies
• Supply interruptions or substitution by competing ^13C-urea kits

What regulatory and reimbursement factors typically influence adoption?

The combination’s adoption is driven by:

• Marketing authorization status (by country)
• Coverage policies for H. pylori diagnosis and test-of-cure
• Clinical pathway rules (when UBT is required vs optional)

In practice, the highest volume occurs where UBT is a payer-supported alternative to endoscopy for confirmation and eradication verification.

Clinical trial signal: what should investors look for in this class?

For ^13C-urea breath testing products, the trial signal typically focuses on:

• Analytical accuracy (breath ^13CO2 detection performance)
• Clinical sensitivity and specificity for active infection and test-of-cure status
• Safety and tolerability
• Workflow outcomes (collection success rate, time to result)

Without a verifiable set of current trials for this exact combination, it is not possible to provide an evidence-based “trial-by-trial” update.

Market outlook by geography: directional view

A numeric geography split requires country-level prevalence, guideline adoption rates, and reimbursement coverage for ^13C-UBT and/or comparable UBT kits.

Directional patterns across the market include:

• Higher uptake in regions with strong outpatient gastroenterology infrastructure and payer acceptance of noninvasive diagnostics
• More substitution risk in settings where stool antigen has broader coverage or where endoscopy use is reimbursed without as much pathway friction
• Instrument platform effects where labs standardized on a specific breath analysis system

Key competitive differentiators that matter for citric acid; urea C-13 procurement

Procurement teams typically weight:

• Cost per completed test
• Compatibility with existing breath analysis workflows
• Packaging and stability for clinical operations
• Regulatory standing and ability to maintain consistent supply

Because the underlying diagnostic principle is shared across UBT products, differentiation is most often operational.

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Key Takeaways

• Citric acid; urea C-13 is a UBT diagnostic tracer used for H. pylori diagnosis and test-of-cure workflows.
• A complete clinical trials update for this exact combination cannot be produced from available source material in a way that meets the accuracy requirements of this format.
• Market growth is driven by test-of-cure adherence, outpatient adoption, and reimbursement support for noninvasive H. pylori diagnostics.
• The closest competitive frame is the ^13C-urea UBT kit set plus alternative noninvasive diagnostics such as stool antigen.
• Near-term investment and R&D attention should focus on workflow performance and reimbursement and distribution execution, not only on clinical claims.

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FAQs

1. Is citric acid; urea C-13 a treatment or a diagnostic?
   It is a diagnostic tracer for urea breath testing used to evaluate H. pylori status.

2. What does the “C-13” indicate in this product?
   ^13C labeling supports detection of ^13CO2 in exhaled breath after administration of ^13C-urea.

3. What clinical scenarios use this type of test?
   It is used for H. pylori diagnosis and test-of-cure after eradication therapy.

4. What drives market adoption for ^13C UBT kits?
   Reimbursement coverage, test-of-cure pathway adoption, and procurement economics (cost per test and workflow fit).

5. What are the key substitutes?
   Stool antigen testing and, in some pathways, endoscopy-based testing.

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References

[1] ClinicalTrials.gov. (n.d.). Database search results for citric acid; urea C-13. https://clinicaltrials.gov/
[2] WHO International Clinical Trials Registry Platform (ICTRP). (n.d.). Database. https://trialsearch.who.int/
[3] European Union Clinical Trials Register (EU CTR). (n.d.). Database. https://www.clinicaltrialsregister.eu/