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Not yet recruitingNCT07873632Updated Oct 14, 2026

Study to Evaluate the Effects of Oral Glyceryl Guiacolate (Guaifenesin, GGE) on Sputum Rheology in Subjects With Mucus Hypersecretion

A Phase 4 interventional study of Glycerol Guiacolate and SOC (Standard of care) in Bronchitis and Bronchitis, Chronic, sponsored by University of North Carolina, Chapel Hill. Not yet recruiting at 1 site in United States. Open to participants aged 40 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-14.

Sponsored by University of North Carolina, Chapel Hill · Phase 4, Interventional, and Treatment

Updated Oct 14, 2026Newly registeredGo to Updates ↓
Phase
Phase 4
Study type
Interventional
Enrollment
40
Allocation
Randomized
Ages
40 Years to 75 Years
Sex
All
01

Study summary

A Randomized, Dosing vs Standard of Care, Single-Center, Multiple Dose Study to Evaluate the Effects of Oral Glyceryl Guiacolate (Guaifenesin, GGE) on Sputum Rheology in Subjects With Mucus Hypersecretion

Read the detailed description

The objective is to confirm GGE's impact on transforming mucus to optimal form that facilitates its loosening from airway walls and improves mucociliary clearance. The investigators propose a standard of care (SOC defined as all current medications prescription and non-prescription drugs and supplements) controlled clinical trial involving 40 participants (20 GGE / 20 SOC) with stable chronic bronchitis ((defined as subjects with chronic productive cough that occurs daily for at least 3 months in 2 consecutive years, in a patient who has not had an acute exacerbation within the previous 4 weeks; where an acute exacerbation of chronic bronchitis is defined as an acute worsening of a patient's symptoms, beyond normal day-to-day variations, necessitating a change in treatment with antibiotics and/or corticosteroids)). The trial will collect sputum samples before (baseline) and after 14 \& 28 days of daily GGE/SOC administration and assess rheological properties to quantify changes in sputum viscosity, elasticity, and flow properties. These measurements will be evaluated to elucidate whether GGE reduces mucus rigidity and adhesiveness, facilitating clearance by cilia and coughing, while providing insights into its molecular and physiological effects. Mucus plugging will be assessed by CT lung imaging to determine if lung imaging could act as an outcome measure of the effect of GGE/SOC. This integrated approach aims to advance understanding of outcomes to assess GGE's therapeutic potential and guide future research for respiratory diseases characterized by thickened mucus.

02

Conditions studied

  • Bronchitis
  • Bronchitis, Chronic

Keywords

  • Mucinex
  • Stable Chronic Bronchitis
  • Mucus Rheology
  • Mucus Plugging
03

In context

Bronchitis

272 studies on the registry are indexed under Bronchitis; 27 are open to participants now.

This study's planned enrollment of 40 is below the median of 120 across 188 interventional studies indexed under Bronchitis.

Browse Bronchitis studies →

Lead sponsor

University of North Carolina, Chapel Hill is the lead sponsor of 1,366 studies on the registry; 133 are open to participants now.

Of its 158 completed or terminated interventional studies of FDA-regulated products, 139 (88%) have results posted.

Browse University of North Carolina, Chapel Hill studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
40 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

    • Confirmed diagnosis of stable chronic bronchitis (defined as subjects with chronic productive cough that occurs daily for at least 3 months in 2 consecutive years, in a patient who has not had an acute exacerbation within the previous 4 weeks; where an acute exacerbation of chronic bronchitis is defined as an acute worsening of a patient's symptoms, beyond normal day-to-day variations, necessitating a change in treatment with antibiotics and/or corticosteroids).

      • Ability to produce spontaneous sputum and non-reactive to hypertonic saline for induced sputum collection.
      • Stable disease (no exacerbations requiring hospitalization in the past 28 days).
      • A Pulmonary Function Test with Forced Expiratory Volume in 1st second (FEV1) FEV1/Forced Vital Capacity (FVC) less than 0.7 (70%) but greater than 0.4 (40%) at the time of enrollment and at least a 10-year history of cigarette use.
      • Participants who have not used guaifenesin-containing products within one month of the time of study enrollment.
      • Adults age 40-75 with stable chronic bronchitis with persistent cough.

Exclusion criteria

Exclusion Criteria:

    • Current use of mucolytics (e.g., N-acetylcysteine), corticosteroids, or other GGEs known to alter mucus properties.

      • Severe comorbidities (e.g., Gastroesophageal Reflux Disease (GERD), heart failure, advanced Chronic Obstructive Pulmonary Disease (COPD,) or cystic fibrosis).
      • Smokers (within the past year). Note: Participants with a positive cotinine test at the baseline visit will be dropped from the study.
      • Recent viral infection or other pulmonary exacerbation (\< 1 month).
      • Participants who are pregnant or breastfeeding.
      • Pulmonary diagnosis other than Chronic Bronchitis (CB) (such as cystic fibrosis, alpha-1 antitrypsin deficiency, bronchiectasis, or pulmonary fibrosis) or active lung cancer.
      • Participation in another study involving an investigational product within 30 days of the baseline visit.
      • Known allergy to the study GGE or its components.
      • History of alcohol and/or drug abuse within one year of study start.
      • Participants taking intermittent antibiotics and participants taking oral and systemic corticosteroids (e.g., prednisone at a dose of > 10 mg/day). (Note: Participants on a chronic stable dose of macrolide antibiotics at the start of the study may be included at the discretion of the Principal Investigator.)
      • Participants who had an acute exacerbation of chronic bronchitis within one month of starting the study that required systemic steroids or antibiotics.
      • Hypersensitivity to hypertonic saline, guaifenesin, or any other excipient listed in the product.
      • Inability to provide informed consent.
05

Study design

Phase
Phase 4
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
40 participants (estimated)

Study arms

  • Experimental
    Glycerol Guiacolate

    Glycerol Guiacolate (Mucinex) Extended release 2 x 600 mg tablets bis in die (BID)

    Drug: Glycerol Guiacolate

  • Other
    Standard of Care

    Current medication Participant is currently using

    Drug: SOC (Standard of care)

Interventions

  • DrugGlycerol Guiacolate

    Participants will receive 28 days (+3 days for flexible scheduling) dosing of Glycerol Guiacolate (GGE) (2 x 600 mg for a total of 1200mg) taken twice daily (total of 2400 mg) in addition to current medications.

    Also known as: Mucinex

  • DrugSOC (Standard of care)

    Current medication excluding mucolytics or steroids

06

What researchers measure

Primary outcomes

  1. Change in mucus viscosity

    measurement of mucus viscosity

    Time frame: Baseline to end of treatment (Day 28)

  2. Change in mucus elasticity

    measurement of mucus elasticity

    Time frame: Baseline to end of treatment (Day 28)

  3. Change in mucus concentration

    measurement of mucus concentration

    Time frame: Baseline to end of treatment (Day 28)

Secondary outcomes

  1. CT Quantitation of airway mucus plugs

    Change in mucus plug score from baseline to day 28. Segments will be scored as 0 (absent) or 1 (present) for mucus plugs. A total segment score ranging from 0 to 18 for each patient will be calculated. A decrease in the mucus plug score reflects a beneficial finding.

    Time frame: Baseline to day 28.

07

Study locations

1 site
08

References and documents

Individual participant data

Plan to share: Yes — Deidentified individual data that supports the results will be shared beginning 9 and continuing for 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with UNC.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form

Time frame: beginning 9 and continuing for 36 months following publication

Access criteria: Investigator has approved IRB, IEC, or REB and an executed data use/sharing agreement with UNC.

No publications or documents are linked to this record.

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Start is estimated for Oct 2026; primary completion for Dec 2027, 14 months later.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 30, 2026
First posted
Oct 14, 2026
StartEst.
Oct 2026
Primary completionEst.
Dec 31, 2027
CompletionEst.
Mar 31, 2028
Last update
Oct 14, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Registered
First appeared on the registry. No changes since
Oct 14, 2026
Show all 1 update
  1. Oct 14, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07873632
Lead sponsor
University of North Carolina, Chapel Hill
Collaborators
Reckitt Benckiser Healthcare (UK) Limited
Responsible party
Sponsor
First posted
Oct 14, 2026
Start date
Oct 2026 (estimated)
Primary completion
Dec 31, 2027 (estimated)
Completion
Mar 31, 2028 (estimated)
Last update
Oct 14, 2026

Study contacts

Brian Button, PhD
Contact
brian_button@med.unc.edu
919-966-8073
Carole Robinette, MS, CPFT, ACSM:CEP
Contact
carole_robinette@med.unc.edu
919-966-5638
Brian Button, PhD
principal investigator · University of North Carolina, Chapel Hill

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.

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