In vitro safety evaluation of sunscreen formulation from nanostructured lipid carriers using human cells and skin model.

There is a risk of toxicological reactions due to systemic absorption and photo-instability of sunscreens. The study aimed to investigate the safety profile (cytotoxicity, phototoxicity, photostability, UV filter release profile, and skin irritation properties) of sunscreen (NLC-TRF sunscreen) produced from nanostructured lipid carriers (NLCs) and tocotrienol-rich fraction (TRF). The cytotoxicity and phototoxicity of the sunscreen were evaluated on normal human dermal fibroblast (NHDF) and skin irritation properties was tested on skin model. Besides, the photoprotection in pre- and post-UV irradiation were analysed to determine the photostability. Additionally, the release profile for UV filters (diethylamino hydroxybenzoyl hexyl benzoate (DHHB) and ethylhexyl triazone (EHT)) were evaluated. The NLC-TRF sunscreen demonstrated no cytotoxicity and skin irritation to cause cell death. It showed no phototoxic effect and high photostability up to 10 Minimal Erythema Dose (MED) to ensure high SPF value above 50 and broad-spectrum of UV absorption. The NLC-TRF sunscreen implies its safety for topical application with sustainable release profile for UV filter (cumulative release of 28% for DHHB and 40% for EHT after 8 h) due to the application of NLCs. The results suggest that the NLC-TRF sunscreen is an advanced formulation with improved stability and is safe for topical delivery.

In Vitro Antiaging Evaluation of Sunscreen Formulated from Nanostructured Lipid Carrier and Tocotrienol-Rich Fraction.

Chronic exposure to ultraviolet (UV) radiation leads to photoaging. There is a tremendous rise in products having a dual activity of photoprotection and antiaging. In vitro analysis in dermal fibroblasts and their biological mechanisms involved are critical to determine antiaging potential. The study aimed to investigate the antiaging potential of sunscreen formulated from nanostructured lipid carrier and tocotrienol-rich fraction (NLC-TRF sunscreen). The antioxidant activity of the NLC-TRF sunscreen was evaluated by radical scavenging and hydrogen peroxide inhibition properties. Also, collagenase, elastase and matrix metalloproteinase-1 (MMP-1) inhibition activities, and type I collagen and elastin protein expression were studied. Quantitative real-time polymerase chain reaction (qPCR) was used to evaluate the mRNA expression of fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), transforming growth factor-ß1 (TGF-ß1), type I collagen (COL1A1), elastin (ELN), MMP-1, MMP-2, and tissue inhibitor matrix metalloproteinase-1 (TIMP-1). The results suggested that NLC-TRF sunscreen is effective in radical, anti-hydrogen peroxide, and collagenase, elastase and MMP-1 inhibition activities. Besides, a significant increase for type I collagen (3.47-fold) and elastin (2.16-fold) protein and fibroblast regeneration genes (FGF (2.12-fold), VEGF (1.91-fold), TGF-ß1 (2.84-fold), TIMP-1 (1.42-fold), ELN (2.13-fold)) were observed after sample treatment. These findings support the therapeutic potential of NLC-TRF sunscreen in antiaging.

Preparation and Evaluation Pumpkin Seed Oil-based Vitamin E Cream Formulations for Topical Application.

Plant seed oil is often incorporated into the cream emulsions to provide multifunctional effects on the skin. In the current study, pumpkin seed oil (PSO) was used to develop a stable oil-in-water emulsion. The study aimed to optimise PSO cream formulation and determine the synergistic effect of the PSO with vitamin E oil added. The physical properties, antioxidant activities and storage stability of the formulations were analysed. Besides, the synergistic effect of the best formulation was analysed based on α-tocopherol content using ultra-high performance liquid chromatography (UHPLC). The storage stability test was assessed upon storing at 25 ± 2°C and 40 ± 2°C for 12 weeks. The best formulation (20% PSO, vitamin E oil and beeswax) selected showed physically and microbiologically stable. The incorporation of vitamin E oil into the formulation produced with PSO was found to be compatible, as it showed a synergistic effect in the amount of α-tocopherol content (combination index (CI) = 0.98). Thus, PSO had shown its potency to be incorporated into the topical products with a promising potential in delivering additional properties that can nourish the skin.