Development of Phytocosmeceutical Microemulgel Containing Flaxseed Extract and Its In Vitro and In Vivo Characterization

Abstract

Antioxidants from natural sources are extensively attaining consideration to avert the skin from damage and aging caused by free radicals. Flaxseed (Linum usitatissimum L.), a natural therapeutic agent, was meant to be explored cosmeceutical by quantifying its potential phytoconstituents and to be incorporated into a microemulgel for topical use. Hydroalcoholic fractions (both methanolic and ethanolic; 80%) flaxseed extracts were subjected to phytochemical screening by quantifying total phenolic content (TPC), total flavonoid content (TFC), and high-performance liquid chromatography-ultraviolet (HPLC-UV), and for biological activities through 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, tyrosinase inhibition assay, and sun protection factor (SPF). Ethanolic fraction was selected for further study by TPC (18.75 mg gallic acid equivalent/g) and TFC (1.34 mg quercetin equivalent/g). HPLC-UV analysis showed the existence of benzoic, quercetin, caffeic, vanillic, p-coumaric, gallic, cinnamic, syringic, and sinapic acids. Biological activities showed 87.00%, 72.00%, and 21.75 values for DPPH assay, tyrosinase inhibition, and SPF assays, respectively. An oil-in-water (OW) microemulsion containing the flaxseed extract, with 99.20 nm Zeta size, −19.3 Zeta potential and 0.434 polydispersity index was developed and incorporated in Carbopol-940 gel matrix to formulate an active microemulgel with 59.15% release in in vitro studies. The successfully formulated stable active microemulgel produced statistically significant effects (p < 0.05), in comparison to a placebo, on skin erythema, melanin, sebum, moisture, and elasticity, in a noninvasive in vivo study performed on 13 healthy human female volunteers. Other cosmeceutical products can also be formulated from flaxseed, making it a considerable candidate for further utilization in the pharmaceutical industry.