Tocopherol succinate-loaded ethosomal gel synthesized by cold method technique: Deeper biophysical characterizations for translational application on human skin.

BACKGROUND: Tocopherols are well-known antioxidant and moisturizing agent. Tocopherol succinate (TS) are widely used in many skin products especially used in anti-aging and skin whitening product formulation. AIM: We previously reported the successful synthesis and preliminary characterizations of stable TS ethosomal gels (TSEG) (DOI: 10.1111/jocd.14907). Herein, we develop and further characterize TSEG to enhance the stability of the developed formulation with increased permeation through skin. METHODS: Cold method technique was used to prepare TS ethosomes. The developed ethosomal vesicle size was 250 nm, which allowed TS to penetrate through the stratum corneum layer and act on melanocytes. For stability study was assessed by thermogravimetric analysis (TGA) by placing TSEG and unloaded/control ethosomal gel (CEG) at various temperature conditions, that is, 8°C, 25°C, 40°C, and 40°C ± 75% RH for 3 months. Organoleptic evaluation was done in terms of color, odor, and phase separation. Transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FTIR), x-ray diffraction spectroscopy (XRD), zeta potential (ZP) and particle size (PS) was used for TSEG physical characterizations. In vitro dissolution and ex-vivo permeation studies (using Franz diffusion cell) were performed for both TSEG and CEG formulations. Human women (N = 34) were used to evaluate in vivo biophysical parameters including erythema, melanin, moisture content, sebum level, and skin elasticity. RESULTS: Developed formulation was highly thermostable during the 3 months. Erythema, melanin, and sebum level decreased while marked improvement (p < 0.05) in moisture content and elasticity have been observed for the developed TSEG. CONCLUSION: The developed TSEG formulation was found to be efficient, safe (no adverse effects observed), stable (at least for 3 months), and easy to use for topical application with improved skin complexation and skin integrity.

Nanostructured Ethosomal Gel Loaded with Arctostaphylosuva-Ursi Extract; In-Vitro/In-Vivo Evaluation as a Cosmeceutical Product for Skin Rejuvenation.

BACKGROUND: Arctostaphylosuva-ursi(AUU) being rich in polyphenols and arbutin is known to have promising biological activities and can be a potential candidate as a cosmaceutical. Ethosomes encourage the formation of lamellar-shaped vesicles with improved solubility and entrapment of many drugs including plant extracts. OBJECTIVE: The objective of this work was to develop an optimized nanostructured ethosomal gel formulation loaded with AUU extract and evaluated for skin rejuvenation and depigmentation. METHODS: AUU extract was tested for phenolic and flavonoid content, radical scavenging potential, reducing power activity, and in-vitro SPF (sun protection factor) estimation. AUU loaded 12 formulations were prepared and characterized by SEM (Scanning Electron Microscopy), vesicular size, zeta potential, and Entrapment Efficiency (%EE). The optimized formulation was subjected to noninvasive in-vivo investigations after incorporating it into the gel system and ensuring its stability and skin permeation. RESULTS: Ethosomal vesicles were spherical in shape and Zeta size, zeta potential, PDI (Polydispersity Index), percentages of EE and in-vitro skin permeation of optimized formulation (F3) were found to be 114.7nm, -18.9mV, 0.492, 97.51±0.023%, and 79.88±0.013% respectively. AUU loaded ethosomal gel formulation was stable physicochemically and exhibited non-Newtonian behavior rheologically. Moreover, it significantly reduced skin erythema, melanin as well as sebum level and improved skin hydration and elasticity. CONCLUSION: A stable AUU based ethosomal gel formulation could be a better vehicle for phytoextracts than conventional formulations for cosmeceutical applications such as for skin rejuvenation and depigmentation.