Ex Vivo and In Vivo Assessment of the Penetration of Topically Applied Anthocyanins Utilizing ATR-FTIR/PLS Regression Models and HPLC-PDA-MS

Anthocyanins are natural colorants with antioxidant properties, shown to inhibit photoaging reactions and reduce symptoms of some skin diseases. However, little is known about their penetration through the stratum corneum, a prerequisite for bioactivity. The aim was to investigate anthocyanin penetration from lipophilic cosmetic formulations through the skin using a porcine ear model and human volunteers. ATR-FTIR/PLS regression and HPLC-PDA-MS were used to analyze anthocyanin permeation through the stratum corneum. Penetration of all anthocyanins was evident and correlated with molecular weight and hydrophilicity. Lower-molecular-weight (MW) anthocyanins from elderberry (449–581 Da) were more permeable within the skin in both ex vivo and in vivo models (K_p = 2.3–2.4 × 10⁻⁴ cm h⁻¹) than the larger anthocyanins (933-1019 Da) from red radish (K_p = 2.0–2.1 × 10⁻⁴ cm h⁻¹). Elderberry and red radish anthocyanins were found at all levels of the stratum corneum and at depths for activity as bioactive ingredients for skin health.

Antioxidant, UV Protection, and Antiphotoaging Properties of Anthocyanin-Pigmented Lipstick Formulations

Consumer demand for foods and cosmetics containing naturally derived ingredients has been increasing. Naturally derived anthocyanins (ACNs), from fruits and vegetables, were previously demonstrated to provide a wide range of hues as lipstick colorants with high stability. Therefore, the objective of this study was to evaluate the use of ACNs as bioactive pigments in lipstick formulations. Commercially available sources of nonacylated and acylated derivatives of the six major ACN aglycones were incorporated into a commercial lipstick base. The ACN-containing lipsticks were evaluated for their ability to act as ultraviolet (UV) absorbers [a source of sun protection factor (SPF)], free radical scavengers against 2,2-diphenyl-1-picrylhydrazyl (DPPH), and preventers of melanin formation through tyrosinase inhibition. All formulas showed increased UV absorption over the lipstick base, and acylated ACNs contributed to the highest in vitro SPF (UVB) values (≥15.8) in formulations. All formulas exhibited high inhibition of DPPH free radicals and inhibition of melanin production by tyrosinase at microgram per milligram concentrations similar to or less than kojic acid (2.41 ± 0.06 µg/mg). This is physiologically relevant because lipstick use is on average 24 mg/day. This study suggests the potential for ACNs to be used as biologically active ingredients in lipstick formulations by acting as antioxidants and UV-protection and antiaging compounds.

Color profiles and stability of acylated and nonacylated anthocyanins as novel pigment sources in a lipstick model: A viable alternative to synthetic colorants

Cosmetics, such as lipstick, can affect an individual's perception of attractiveness and morale. Consumer concern with the safety of synthetic colorants has made the need for alternative natural color sources increasingly urgent. Our goal was to evaluate the feasibility of anthocyanin (ACN) extracts as colorants in lipstick formulations. Lipstick formulations were colored with ACN-rich materials. Accelerated environmental testing typical of the cosmetic industry were used: incubation at 20°, 37°, and 45°C for 12 weeks and temperature abuse cycles between 20°/37°C or -20°/20°C. Color (CIELab) and total monomeric ACN (pH-differential) changes were monitored to determine shelf stability of the product. All formulations exhibited acceptable color for lipsticks. Shelf stability was determined to exceed 2 year based on the accelerated testing conditions. Formulations containing cyanidin as their main ACN were the most stable (elderberry, purple corn, and purple sweet potato). ACNs could be used as suitable alternatives to synthetic colorants in lipid-based topical formulations.