FREE SHIPPING on orders over $150
Track My Order Manage Subscription Sign In Contact Us
Back to 3 MIN READ
Clinical Skin Compatibility Evaluation of a Multi-Active Cosmetic Serum

AVL Face Serum

Clinical Skin Compatibility Evaluation of a Multi-Active Cosmetic Serum

Single-Application Occlusive Patch Test in Sensitive and Normal Skin Cohorts.

Background

Advanced cosmetic formulations increasingly integrate multiple active ingredients to deliver multi-dimensional skin benefits. Responsible innovation requires that performance-driven design be accompanied by rigorous compatibility validation.

Objective

To confirm the skin compatibility of Eye Cream — a complex multi-active formulation containing 17 active ingredients and 21 amino acids — using standardized single-application occlusive patch testing and quantitative irritation scoring via the M.C.I.I.

Methods

Two independent monocentric, simple-blind patch test studies were conducted under dermatological supervision at an external clinical investigation center. The product was applied pure (undiluted) under 48-hour occlusion. Irritation was quantified using the Mean Cumulative Irritation Index (M.C.I.I.).

Results

The serum demonstrated M.C.I.I. values of 0.06 (sensitive skin cohort, n=54) and 0.12 (normal skin cohort, n=55), both classified as Non-irritating (<0.25).

Conclusion

Despite its formulation complexity (16 active ingredients and a full spectrum of 21 amino acids), the tested serum exhibited low acute irritation potential under high-challenge occlusive conditions.

Introduction

Skincare formulas are getting more complex

Modern dermocosmetic formulations increasingly combine multiple active ingredients to enhance performance. However, combining numerous bioactive components - particularly at meaningful concentrations - introduces potential concerns regarding cumulative or synergistic irritation effects.

The scientific question is straightforward
Does increasing formulation complexity proportionally increase irritation risk?

Patch testing represents one of the most robust first-line assessments of skin compatibility because it:

  • Standardizes dose, exposure time, and assessment criteria
  • Creates a high-challenge scenario (48-hour occlusion)
  • Quantifies reactions using a validated irritation index

As such, single-application occlusive patch testing functions as a critical skin-compatibility gate prior to broader consumer use testing.

The present study evaluates the skin compatibility of a complex multi-active facial serum containing: 16 active ingredients

  • A complete set of 21 amino acids
  • Given this formulation density, structured irritation assessment was essential.

Materials and methods

Safety Assessment & Application Protocol

Safety Assessment & Application Protocol

Study Design

Type: Single-application occlusive patch test

Design: Monocentric, simple-blind

Supervision: Dermatological control

Setting: Independent external clinical investigation center

Application Protocol

Dose: 20 µL

Product state: Pure (undiluted)

Application system: Occlusive Finn Chamber® (8 mm / 50 mm²)

Exposure duration: 48 hours

Assessment timepoints:

  • 30 minutes post-removal
  • 24 hours post-removal

Outcome Measure

Skin reactions were evaluated according to predefined numerical grading scales for:

  • Erythema (E) — redness

Oedema (O) — swelling

AVL Face Serum

Skin Compatibilty Results

M.C.I.I. provides a quantitative measure of irritation potential under the specific study conditions

Results chart
Cohorts Age Range Phototypes Subjects M.C.I.I Classification
Sensitive Skin 18–70 I–IV 54 0.06 Non-irritating
Normal Skin 18–70 I–IV 55 0.12 Non-irritating

* Interpretation Scale (Max possible value: 6)

Results data
Results data

* Both cohorts independently met the Non-irritating classification threshold (<0.25).

Regulatory and Ethical Compliance

The studies were conducted:

  • Under dermatological supervision
  • In accordance with the Declaration of Helsinki (1964) and subsequent updates
  • Following ICH E6 (R2) Good Clinical Practice principles
  • Within the framework of Regulation (EC) No 1223/2009 on Cosmetic Products
  • In alignment with Commission Regulation (EU) No 655/2013 (cosmetic claims)
  • Under GDPR compliance (Regulation (EU) 2016/679)
  • Within a documented quality management system consistent with internationally recognized standards (e.g., ISO 9001)

Results Discussion

Innovation in skincare increasingly relies on intelligent multi-active systems designed to address multiple biological pathways simultaneously. However, high- performance design must be accompanied by equally rigorous validation.

The tested Face Serum integrates:

  • 16 active ingredients
  • A complete profile of 21 amino acids

Rather than assuming compatibility based on ingredient-level safety, the finished formulation was evaluated under controlled, standardized conditions using a 48- hour occlusive patch-test model - a recognized high-challenge scenario for assessing acute irritation potential.

The observed M.C.I.I. values of 0.06 (sensitive skin) and 0.12 (normal skin) fall well below the 0.25 threshold for Non-irritating classification. These results were consistent across two independent cohorts representing different skin reactivity profiles.

Tested at Full Strength

PATCH TESTING IS ONE OF THE CLEANEST FIRST ANSWERS BECAUSE IT:

✓ Pure (Undiluted)
✓ Under Occlusion
✓ Uredefined classification thresholds
✓ Using predefined classification thresholds With quantitative scoring methodology

These Findings demonstrate that formulation complexity, when engineered with precision and balance, can coexist with excellent skin compatibility. The study reinforces a core development principle: Performance and gentleness are not opposing goals they are complementary outcomes of disciplined formulation science.

References

  1. European Parliament & Council. (2009). Regulation (EC) No. 1223/2009 on Cosmetic Products, Official Journal of the European Union. This regulation sets out the legal framework for cosmetic safety assessment in the EU, including requirements for demonstrating product safety prior to market placement.
  2. Scientific Committee on Consumer Safety (SCCS). (2021). Notes of Guidance for the Testing of Cosmetic Ingredients and Their Safety Evaluation (11th Revision, SCCS/1628/21). European Commission. Provides scientific guidance on safety evaluation of cosmetics and ingredients under EU law, including considerations on human data for local effects.
  3. Api, A. M., et al. (2021). Draize human repeat insult patch test (HRIPT): Seven decades of protocols and standardization challenges. Toxicology in Vitro. Highlights variability and historical evolution of HRIPT approaches relevant to skin compatibility assessment.