Irritant Contact Dermatitis
Conditions
Brief summary
Irritant dermatitis is one of the most common inflammatory skin disorders, caused by exposure to external substances that induce inflammation and immune activation. Standard management includes avoidance of irritants, restoration of the skin barrier using emollients, and the application of anti-inflammatory drugs such as topical corticosteroids. However, due to the risks associated with long-term corticosteroid use, there is an interest in developing emollient formulations enriched with bioactive compounds possessing anti-inflammatory properties. Among those promising compounds is glycyrrhetinic acid. 18β-Glycyrrhetinic acid, a bioactive component of licorice root extract, exhibits potent anti-inflammatory and antioxidant effects. Topical application has demonstrated beneficial outcomes in conditions such as atopic dermatitis, acne, pruritus, and UVB-induced skin damage. Its proposed mechanisms of action include inhibition of key inflammatory enzymes (COX, 5-LOX, iNOS) and promotion of skin regeneration through stimulation of aquaporin-3 expression and enhancement of epidermal turnover. Topical application of formulations containing 18β-glycyrrhetinic acid will improve skin parameter disturbances caused by irritation induced with sodium lauryl sulfate. This study aims to evaluate the effects of 18β-glycyrrhetinic acid on human skin parameters in an acute irritant dermatitis model induced by sodium lauryl sulfate, providing further insight into its potential role as an anti-inflammatory and barrier-restoring agent. Funding: Funded by the European Union - NextGenerationEU. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them.
Interventions
PROCEDURESLS induced irritation
Skin irritation will be induced on 4 defined test sites on one forearm (randomly selected forearm) using 60 uL of 1% w/v sodium lauryl sulfate (SLS) aqueous solution under occlusion for a defined period to create a controlled model of acute irritant dermatitis. The contralateral forearm will remain untreated and serve as intact skin for comparison. Following the induction phase, all test products (placebo and active formulations) will be applied to both irritated and intact sites according to the treatment allocation.
OTHERNo Treatment
Designated test area with no topical application after irritation (on the irritated forearm) and on corresponding intact skin (on the non-irritated forearm). Serves as a baseline reference for spontaneous recovery and physiological skin variability.
OTHERPlacebo
Topical formulation identical in composition to the active preparations but without glycyrrhetinic acid. Used to evaluate the effect of the formulation vehicle on skin parameters. Applied daily to designated test sites on both irritated and intact forearm areas for the duration of the study.
OTHERLow Dose Glycyrrhetinic Acid Formulation
Topical formulation containing a low concentration of 18β-glycyrrhetinic acid. Designed to assess the effects of the active compound at a low dose on skin barrier recovery and skin parameters following SLS-induced irritation. The formulation is applied daily to designated test sites on both irritated and intact forearm areas for the duration of the study.
OTHERHigh Dose Glycyrrhetinic Acid Formulation
Topical formulation containing a high concentration of 18β-glycyrrhetinic acid. Designed to assess the effects of the active compound at a high dose on skin barrier recovery and skin parameters following SLS-induced irritation. The formulation is applied daily to designated test sites on both irritated and intact forearm areas for the duration of the study.
OTHERIntermediate Dose Glycyrrhetinic Acid Formulation
Topical formulation containing an intermediate concentration of 18β-glycyrrhetinic acid. Designed to assess the effects of the active compound at an intermediate dose on skin barrier recovery and skin parameters following SLS-induced irritation. The formulation is applied daily to designated test sites on both irritated and intact forearm areas for the duration of the study.
Sponsors
University of Split, School of Medicine
European Union
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Healthy adult participants aged 18 years or older, of any sex. * Intact, healthy skin at the test sites. * No use of systemic or topical corticosteroids, immunomodulators, or antihistamines within the previous three months. * No use of topical emollients on the test sites within the previous seven days.
Exclusion criteria
* Pregnant women, women suspected of being pregnant, and breastfeeding women. * Non-compliance with the study protocol. * Voluntary withdrawal or personal decision not to continue participation.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Erythema | 1st, 2nd, 3rd, 4th, 5th, 8th and 10th day of the trial | Mexameter will be used to assess erythema. It is a relative measurement and uses arbitrary units (AU). |
| Skin elasticity | 1st, 2nd, 3rd, 4th, 5th, 8th and 10th day of the trial | Cutometer will be used to assess skin elasticity. |
| Transepidermal water loss | 1st, 2nd, 3rd, 4th, 5th, 8th and 10th day of the trial | Tewameter will be used to assess skin barrier function as a measurement of the water loss (g/m2/h). |
| Hydration | 1st, 2nd, 3rd, 4th, 5th, 8th and 10th day of the trial | Corneometer will be used to estimate skin dryness. It is a relative measurement and uses arbitrary units (AU). |
Countries
Croatia
Outcome results
None listed