Pain Induced by m-Cresol as Preservative

NCT07600814 | Not Yet Recruiting Early Phase 1

• 1 other identifier: EK1688/2024
• Study Type: interventional
• Target: 18
• Locations: 0 countries
• Sites: N/A

Brief Summary

Preservatives such as m-Cresol are essential components in many subcutaneously injected medications, including insulin or human growth hormone, to prevent bacterial growth. However, clinical reports have suggested that these preservatives may cause local discomfort or pain at the injection site, which can negatively impact treatment adherence. While m-Cresol is widely used, its direct contribution to injection-site pain has not yet been investigated in a prospective clinical trial. This study aims to investigate whether subcutaneous injection of m-Cresol at concentrations commonly used in clinical practice (0.1% and 0.25%) cause significantly more pain than a preservative-free control solution. In a randomized, double-blind crossover design, healthy volunteers will receive three separate injections in a belly fold. Participants will rate their pain every 5 seconds until it subsides. The findings will help determine if m-Cresol is a primary source of injection-site pain and could lead to the development of more comfortable drug formulations.

Conditions

Pain; Acute Pain; Healthy Volunteer Study

Keywords

m-Cresol; Preservative; Subcutaneous Injection; Human Pain Models; Experimental Pain Models; Nociception

Outcome Measures

Primary Outcomes (1)

• Area Under the Curve (AUC) of Pain Intensity

  Total pain burden calculated as the Area Under the Curve of serial pain ratings (0-100 numerical pain rating scale) recorded every 5 seconds from the start of injection until no pain is reported for 30 seconds.

  From injection start until pain subsides (approximately 15-60 seconds per injection).

Study Arms (3)

m-Cresol 0.1%

EXPERIMENTAL

Participants receive a 300 µl subcutaneous injection of m-Cresol at a concentration of 0.1%.

Other: m-Cresol 0.1%

m-Cresol 0.25%

EXPERIMENTAL

Participants receive a 300 µl subcutaneous injection of m-Cresol at a concentration of 0.25%.

Other: m-Cresol 0.25%

Control solution

PLACEBO COMPARATOR

Participants receive a 300 µl subcutaneous injection of control solution.

Other: Control Solution

Interventions

m-Cresol 0.1% OTHER

A preservative administered subcutaneously at 0.1%, a common concentration used in medicines.

m-Cresol 0.1%

m-Cresol 0.25% OTHER

A preservative administered subcutaneously at 0.25%, a common concentration used in medicines.

m-Cresol 0.25%

Control Solution OTHER

A control solution administered subcutaneously.

Control solution

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 70 years

You may not qualify if:

• Participant of another study, ongoing or within the last four weeks
• Current medication intake (except hormonal contraception) or drug abuse
• Female subjects: Positive pregnancy test or breastfeeding
• Body temperature above 38°C, verified by infrared thermometer
• Known allergic diseases, in particular asthmatic disorders and skin diseases
• Sensory deficit, skin disease or hematoma of unknown origin in the examination of the test site

Sponsors & Collaborators

• Medical University of Vienna: lead

MeSH Terms

Conditions

Pain; Acute Pain

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Michael J.M. Fischer

  Medical University of Vienna

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Felix J. Resch

CONTACT

+43 1 40160 31419; felix.resch@meduniwien.ac.at

Michael J.M. Fischer

CONTACT

+43 1 40160 31410; michael.jm.fischer@meduniwien.ac.at

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 15, 2026
• First Posted: May 22, 2026
• Study Start (Estimated): May 25, 2026
• Primary Completion (Estimated): June 8, 2026
• Study Completion (Estimated): June 8, 2026
• Last Updated: May 22, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: IPD will be made available at the time of publication of the primary resultsarticle, as a supplementary file.
• Access Criteria: All individuals who have access to the published article will be able to access the individual participant data (IPD) and supporting information as supplementary material. No special request or data use agreement is required.