The integration of vegetable oils rich in polyunsaturated fatty acids (PUFAs) into cosmetic formulations offers significant benefits for skin health, such as improving membrane fluidity and barrier function. However, these unsaturated lipids are highly susceptible to oxidative degradation and lipid peroxidation, which can lead to the formation of reactive oxygen species (ROS) that contribute to skin aging. To address this issue, researchers developed the Andean Skin Care (ASC) Cream, a solution incorporating extracts and oils from Peruvian biodiversity, including Croton lechleri (sangre de grado) and oils from aguaje, aguaymanto, and sacha inchi. These specific natural sources were selected because their high concentrations of phenolic compounds and tocopherols act as natural antioxidants, potentially stabilizing the formulation and protecting the sensitive lipid components from thermal and oxidative stress.
Methods
The researchers subjected the ASC Cream to accelerated stability testing at 40°C for six months to simulate a real-time shelf life and evaluate its functional durability. FTIR-ATR spectroscopy was utilized to characterize the chemical structure and identify functional groups at the initial time point and after the stability period. Antioxidant capacity was quantitatively assessed using DPPH and ABTS radical scavenging assays, with the results statistically compared to a premium commercial reference cream. These methodologies allowed for a comprehensive evaluation of both the structural integrity and the functional efficacy of the formulation under stress conditions.
Key Findings
- High Structural Stability: FTIR-ATR analysis revealed that the spectral curves before and after the stability period were almost completely superimposed, showing a 0.9825 correlation coefficient, indicating no significant changes in the chemical structure.
- Preserved Antioxidant Efficacy: After six months of accelerated stability (ASC T6), the formulation maintained a DPPH radical inhibitory capacity (IC50 of 5744.86 µg/mL) that was statistically comparable to the commercial reference product (5641.16 µg/mL).
- Functional Group Integrity: The study confirmed the preservation of essential hydroxyl, carbonyl, and ether functional groups, which are critical for the stability of the lipid-polymeric emulsifying system.
- Synergistic Protection: The maintenance of antioxidant activity is attributed to the synergistic interactions between the phenolic compounds in the plant extracts and the lipophilic antioxidants naturally present in the Peruvian vegetable oils.
- Dose-Dependent Response: Both the initial and stabilized versions of the cream exhibited a clear linear relationship between concentration and radical inhibition, confirming reliable in vitro performance.
The novelty of this research lies in its demonstration that a natural cosmetic matrix derived from Peruvian biodiversity can achieve a functional shelf life and structural stability comparable to high-end international commercial products. Unlike many studies that only evaluate initial antioxidant activity, this research provides “added value” by predicting the long-term functional efficacy of the formulation under thermal stress. The future implications of these findings suggest that species like Plukenetia huayllabambana and Mauritia flexuosa are viable, sustainable alternatives for the global “clean beauty” industry. Moving forward, the researchers recommend optimizing the formulation with additional complementary antioxidants and performing in vivo instrumental assessments to further validate the cream’s efficacy and safety on human skin.
Link to the study: https://www.mdpi.com/2079-9284/13/2/57
