HealthyEarly Phase 1NCT07778472
Topical Tripelennamine 1% Cream Versus Diphenhydramine 1% Cream for the Relief of Histamine-Induced Itching: A Proof Concept Study in Healthy Adults.
A Early Phase 1 study testing Tripelennamine and Diphenhydramine in people with Healthy, run by Palm Beach Atlantic University at 1 site in United States.
Trial summary
The goal of this clinical trial is to determine whether topical tripelennamine 1% cream can relieve histamine-induced itching and whether it is more effective than diphenhydramine 1% cream in healthy adults aged 18 to 50 years. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Tripelennamine and Diphenhydramine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 37 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Feb 2025to 18 Sep 2025
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Must be in general good health with no disease or physical conditions that would impair evaluation of itch and pain perception.
- No history of chronic itch or pain.
- Must abstain from the use of any systemic or topical antihistamine, steroid, or pain relief medications from the week prior to the study till the completion of the study.
- Must abstain from the use of moisturizers on the arms 24 hours before study visit.
Who cannot join
- Inability to complete the required measures.
- The presence of an itchy skin disease.
- Diagnosis of disease that would affect itch or pain perception (e.g. neuropathies).
- Currently enrolled in any investigational study in which the subject is receiving any type of drug, biological, or non-drug therapy.
- Use of oral, topical analgesics, or other medications known to interfere with itch or pain perception in the week prior to the study and throughout the study (e.g. antihistamines, anesthetics, opioids, neuroleptics, etc.).
- Use of emollients on the arms a week prior to the study and throughout the study.
- Known allergies to tripelennamine and/or diphenhydramine.
- Pregnant women. (Women of childbearing potential will undergo an hCG pregnancy test).
Trial locations and contacts
1 site in 1 country.
United States1 site
Palm Beach Atlantic University
West Palm Beach, Florida, 33401
About this study
The goal of this clinical trial is to determine whether topical tripelennamine 1% cream can relieve histamine-induced itching and whether it is more effective than diphenhydramine 1% cream in healthy adults aged 18 to 50 years.
The main questions it aims to answer are:
Read more
- Does tripelennamine 1% cream reduce the intensity, duration, and peak severity of histamine-induced itch as measured by a visual analog scale (VAS)?
- Does tripelennamine 1% cream reduce the histamine-induced wheal and flare skin responses compared with diphenhydramine 1% cream and vehicle control? Researchers will compare tripelennamine 1% cream, diphenhydramine 1% cream, and a vehicle control cream base to see if tripelennamine provides greater relief of histamine-induced itching and skin reactions.
Participants will:
- Have four test areas marked on their forearms.
- Receive topical application of tripelennamine 1% cream, diphenhydramine 1% cream, and vehicle control cream to randomized test sites.
- Undergo a histamine challenge administered through iontophoresis after treatment application.
- Rate their itch intensity every minute using a 0 to 10 visual analog scale until the itch subsides.
- Have wheal and flare skin reactions assessed every 5 minutes for up to 20 minutes, including photographs and videos of the reactions.
- Report any adverse events for up to one week after study completion.
Read the detailed description
The goal of this clinical trial is to determine whether tripelennamine 1% topical cream is effective in relieving histamine-induced itching and skin reactions and whether it is more effective than diphenhydramine 1% topical cream in healthy adult volunteers aged 18 to 50 years with no history of chronic itch or conditions affecting itch perception. The study was conducted because there are limited over-the-counter topical medications that directly relieve acute itch, creating a need for more effective topical antipruritic treatments.
The main questions it aims to answer are:
- Does tripelennamine 1% cream reduce the intensity of histamine-induced itch, as measured by a visual analog scale (VAS), including overall itch intensity (area under the itch-time curve), peak itch severity, and duration of itching?
- Does tripelennamine 1% cream reduce histamine-induced skin reactions, specifically the magnitude and duration of flare and wheal responses, compared with diphenhydramine 1% cream and vehicle control? Researchers will compare tripelennamine 1% topical cream, diphenhydramine 1% topical cream, and a vehicle control cream base to determine whether tripelennamine provides superior relief of histamine-induced itch and associated skin reactions. The investigators hypothesized that participants treated with tripelennamine would experience significantly less itching and reduced flare and wheal responses following a histamine challenge than those treated with diphenhydramine or vehicle control.
Participants will:
- Provide informed consent and undergo screening to confirm eligibility.
- Have four 4 cm × 4 cm test areas marked on the inner surfaces of both forearms.
- Receive randomized, double-blinded applications of:
- Tripelennamine 1% topical cream,
- Diphenhydramine 1% topical cream, and
- Vehicle control cream base.
- Have approximately 0.2 g of each study cream applied to designated skin sites and left in place for 15 minutes.
- Undergo a histamine challenge at each treatment site using iontophoresis, a procedure that delivers histamine 1% gel through the skin using a low electrical current to induce itching and the characteristic histamine wheal-and-flare response.
- Rate the intensity of itching every minute using a 0 to 10 visual analog scale, where 0 represents "no itch" and 10 represents the "worst itch imaginable," until the sensation completely resolves.
- Have the duration and peak severity of itching recorded for each treatment condition.
- Have skin flare and wheal reactions assessed and scored every 5 minutes for up to 20 minutes after the histamine challenge.
- Have photographs and videos taken of the treatment sites to document flare and wheal responses over time.
- Be monitored for adverse events during the study and report any adverse effects for up to one week after study completion.
This was a single-center, randomized, double-blind, vehicle-controlled clinical trial conducted at Palm Beach Atlantic University. Thirty-seven healthy adults were enrolled and thirty-six participants completed all efficacy assessments included in the final analysis.
- Conditions
- Healthy
- Being tested
- Tripelennamine, Diphenhydramine, Vehicle Control Cream Base
- Keywords
- Tripelennamine, Diphenhydramine, Histamine, Itch, VAS, Iontophoresis
- Medical subject headings
- Pruritus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TripelennamineDrug
Also called Pyribenzamine
Tripelennamine 1% topical cream applied to the skin of one arm of an individual 15 minutes before the application of iontophoretically administered histamine 2% gel.
DiphenhydramineDrug
Diphenhydramine 1% topical cream applied to the skin of one arm of an individual 15 minutes before the application of iontophoretically administered histamine 2% gel.
Vehicle Control Cream BaseDrug
Approximately 0.2 g of vehicle cream base without antihistamine was applied topically to designated forearm test areas.
The cream remained on the skin for 15 minutes before histamine iontophoresis was performed.
| Study group | Role | What they receive |
|---|---|---|
| Vehicle control cream base | Placebo comparator | Participants received a single topical application of vehicle cream base prior to histamine iontophoresis to serve as a control condition. Receives: Drug: Vehicle Control Cream Base |
| Diphenhydramine 1% topical cream | Active comparator | Participants received a single topical application of diphenhydramine 1% cream prior to histamine iontophoresis to evaluate its effect on histamine-induced itch and skin reactions. Receives: Drug: Diphenhydramine |
| Tripelennamine 1% topical cream | Experimental | Participants received a single topical application of tripelennamine 1% cream prior to histamine iontophoresis to evaluate its effect on histamine-induced itch and skin reactions. Receives: Drug: Tripelennamine |
What is being measured
The primary outcome is the main question the study is designed to answer.
VAS
The effectiveness of tripelennamine 1% cream compared to diphenhydramine 1% cream in relieving histamine-induced itching was determined using a visual analogue scale for pruritus (VAS) as an endpoint. The following parameters were determined from the VAS itch score vs time curves: area under the curve, peak VAS itch score and duration of itch.
Measured: Subjects rated their itch intensity every 60 seconds until the itch sensation had completely subsided using a visual analog scale (VAS) for 60 minutes.
Secondary outcomes (1)
Histamine Triple Response
The effectiveness of tripelennamine 1% cream compared to diphenhydramine 1% cream in relieving the histamine-induced triple response was determined via the following endpoints:
- The magnitude of a wheal as a function of time.
- The magnitude of a flare as a function of time.
Measured: Research assistants rated the magnitude of the wheal and flare in 5-minute intervals for up to 20 minutes using a rating of 1-mild, 2-moderate, 3-severe.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Aug 2026
- Study start24 Feb 2025
- Primary completion18 Sep 2025
- Study completion18 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- randomized (to do with the arm of an individual, ie left or right arm), double-blind, vehicle-controlled crossover human study
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 37 participants (actual)
Sponsor and investigators
- Lead sponsor
- Palm Beach Atlantic University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Adwoa Olufunlayo Nornoo, Palm Beach Atlantic University
- Investigators
- David M Compton, PhD, Study chair, Palm Beach Atlantic University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07778472
- Sponsor's protocol ID
- IIIc, 01.21.2025
- Status last verified
- Aug 2026
- First submitted
- 17 Aug 2026
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified participant-level data supporting the published results, including demographics, VAS itch scores, itch duration, peak itch scores, wheal and flare assessments, treatment assignment, and adverse event data.
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Topical Tripelennamine 1% Cream Versus Diphenhydramine 1% Cream for the Relief of Histamine-Induced Itching: A Proof Concept Study in Healthy Adults.
- ClinicalTrials.gov ID
- NCT07778472
- Acronym / sponsor ID
- IIIc, 01.21.2025
- Conditions
- Healthy
- Keywords
- Tripelennamine, Diphenhydramine, Histamine, Itch, VAS, Iontophoresis
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 37 participants (actual)
- Lead sponsor
- Palm Beach Atlantic UniversityUniversity, hospital or other
- Study start
- 24 Feb 2025 (actual)
- Primary completion
- 18 Sep 2025 (actual)
- Study completion
- 18 Sep 2025 (actual)
- First posted
- 21 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to determine whether topical tripelennamine 1% cream can relieve histamine-induced itching and whether it is more effective than diphenhydramine 1% cream in healthy adults aged 18 to 50 years.
The main questions it aims to answer are:
- Does tripelennamine 1% cream reduce the intensity, duration, and peak severity of histamine-induced itch as measured by a visual analog scale (VAS)?
- Does tripelennamine 1% cream reduce the histamine-induced wheal and flare skin responses compared with diphenhydramine 1% cream and vehicle control? Researchers will compare tripelennamine 1% cream, diphenhydramine 1% cream, and a vehicle control cream base to see if tripelennamine provides greater relief of histamine-induced itching and skin reactions.
Participants will:
- Have four test areas marked on their forearms.
- Receive topical application of tripelennamine 1% cream, diphenhydramine 1% cream, and vehicle control cream to randomized test sites.
- Undergo a histamine challenge administered through iontophoresis after treatment application.
- Rate their itch intensity every minute using a 0 to 10 visual analog scale until the itch subsides.
- Have wheal and flare skin reactions assessed every 5 minutes for up to 20 minutes, including photographs and videos of the reactions.
- Report any adverse events for up to one week after study completion.
Detailed description
The goal of this clinical trial is to determine whether tripelennamine 1% topical cream is effective in relieving histamine-induced itching and skin reactions and whether it is more effective than diphenhydramine 1% topical cream in healthy adult volunteers aged 18 to 50 years with no history of chronic itch or conditions affecting itch perception. The study was conducted because there are limited over-the-counter topical medications that directly relieve acute itch, creating a need for more effective topical antipruritic treatments.
The main questions it aims to answer are:
- Does tripelennamine 1% cream reduce the intensity of histamine-induced itch, as measured by a visual analog scale (VAS), including overall itch intensity (area under the itch-time curve), peak itch severity, and duration of itching?
- Does tripelennamine 1% cream reduce histamine-induced skin reactions, specifically the magnitude and duration of flare and wheal responses, compared with diphenhydramine 1% cream and vehicle control? Researchers will compare tripelennamine 1% topical cream, diphenhydramine 1% topical cream, and a vehicle control cream base to determine whether tripelennamine provides superior relief of histamine-induced itch and associated skin reactions. The investigators hypothesized that participants treated with tripelennamine would experience significantly less itching and reduced flare and wheal responses following a histamine challenge than those treated with diphenhydramine or vehicle control.
Participants will:
- Provide informed consent and undergo screening to confirm eligibility.
- Have four 4 cm × 4 cm test areas marked on the inner surfaces of both forearms.
- Receive randomized, double-blinded applications of:
- Tripelennamine 1% topical cream,
- Diphenhydramine 1% topical cream, and
- Vehicle control cream base.
- Have approximately 0.2 g of each study cream applied to designated skin sites and left in place for 15 minutes.
- Undergo a histamine challenge at each treatment site using iontophoresis, a procedure that delivers histamine 1% gel through the skin using a low electrical current to induce itching and the characteristic histamine wheal-and-flare response.
- Rate the intensity of itching every minute using a 0 to 10 visual analog scale, where 0 represents "no itch" and 10 represents the "worst itch imaginable," until the sensation completely resolves.
- Have the duration and peak severity of itching recorded for each treatment condition.
- Have skin flare and wheal reactions assessed and scored every 5 minutes for up to 20 minutes after the histamine challenge.
- Have photographs and videos taken of the treatment sites to document flare and wheal responses over time.
- Be monitored for adverse events during the study and report any adverse effects for up to one week after study completion.
This was a single-center, randomized, double-blind, vehicle-controlled clinical trial conducted at Palm Beach Atlantic University. Thirty-seven healthy adults were enrolled and thirty-six participants completed all efficacy assessments included in the final analysis.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 3
- Model description
- randomized (to do with the arm of an individual, ie left or right arm), double-blind, vehicle-controlled crossover human study
| Arm | Type | Receives |
|---|---|---|
| Vehicle control cream base | Placebo comparator | Drug: Vehicle Control Cream BaseParticipants received a single topical application of vehicle cream base prior to histamine iontophoresis to serve as a control condition. |
| Diphenhydramine 1% topical cream | Active comparator | Drug: DiphenhydramineParticipants received a single topical application of diphenhydramine 1% cream prior to histamine iontophoresis to evaluate its effect on histamine-induced itch and skin reactions. |
| Tripelennamine 1% topical cream | Experimental | Drug: TripelennamineParticipants received a single topical application of tripelennamine 1% cream prior to histamine iontophoresis to evaluate its effect on histamine-induced itch and skin reactions. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Must be in general good health with no disease or physical conditions that would impair evaluation of itch and pain perception.
- No history of chronic itch or pain.
- Must abstain from the use of any systemic or topical antihistamine, steroid, or pain relief medications from the week prior to the study till the completion of the study.
- Must abstain from the use of moisturizers on the arms 24 hours before study visit.
Key exclusion criteria (8 listed)
- Inability to complete the required measures.
- The presence of an itchy skin disease.
- Diagnosis of disease that would affect itch or pain perception (e.g. neuropathies).
- Currently enrolled in any investigational study in which the subject is receiving any type of drug, biological, or non-drug therapy.
- Use of oral, topical analgesics, or other medications known to interfere with itch or pain perception in the week prior to the study and throughout the study (e.g. antihistamines, anesthetics, opioids, neuroleptics, etc.).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TripelennamineAlso: PyribenzamineTripelennamine 1% topical cream applied to the skin of one arm of an individual 15 minutes before the application of iontophoretically administered histamine 2% gel. | Drug | Tripelennamine 1% topical cream |
| DiphenhydramineDiphenhydramine 1% topical cream applied to the skin of one arm of an individual 15 minutes before the application of iontophoretically administered histamine 2% gel. | Drug | Diphenhydramine 1% topical cream |
| Vehicle Control Cream BaseApproximately 0.2 g of vehicle cream base without antihistamine was applied topically to designated forearm test areas. The cream remained on the skin for 15 minutes before histamine iontophoresis was performed. | Drug | Vehicle control cream base |
Primary outcome
VAS
Time frame: Subjects rated their itch intensity every 60 seconds until the itch sensation had completely subsided using a visual analog scale (VAS) for 60 minutes.
The effectiveness of tripelennamine 1% cream compared to diphenhydramine 1% cream in relieving histamine-induced itching was determined using a visual analogue scale for pruritus (VAS) as an endpoint. The following parameters were determined from the VAS itch score vs time curves: area under the curve, peak VAS itch score and duration of itch.
1 secondary outcome
Histamine Triple Response
Time frame: Research assistants rated the magnitude of the wheal and flare in 5-minute intervals for up to 20 minutes using a rating of 1-mild, 2-moderate, 3-severe.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2026.
- Individual participant dataSharing planned: Yes. De-identified participant-level data supporting the published results, including demographics, VAS itch scores, itch duration, peak itch scores, wheal and flare assessments, treatment assignment, and adverse event data.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
David M Compton, PhD study chair
Palm Beach Atlantic University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Tripelennamine and Diphenhydramine in people with Healthy, run by Palm Beach Atlantic University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
VAS (time frame: Subjects rated their itch intensity every 60 seconds until the itch sensation had completely subsided using a visual analog scale (VAS) for 60 minutes.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Aug 2026.