## 1 Introduction
It also prevents hepatocyte damage in rats under various environmental conditions. Silymarin has been found to have an anti-inflammatory effect not only in the liver but also in mice, preventing septic shock and reducing the secretion of nitric oxide, reactive oxygen species, interleukin-1\(\beta\), and prostaglandin E2. It has also been shown to protect neurons by inhibiting the release of nitric oxide, TNF-\(\alpha\), and superoxide anion radicals by microglia cells. This protective effect may be beneficial in preventing inflammatory neurodegenerative conditions like Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Silymarin has also been found to inhibit UV-induced NF-kB activation in keratinocytes, potentially preventing sunburn, inflammation, and skin damage induced by UV exposure, which may lead to cancer. Silybin can be used to create products that shield the skin from UV rays, such as cosmetic creams, and is of significant interest in the cosmetics industry, particularly for anti-aging and anti-free radical products. In the presence of phospholipids, silybin can undergo transformations, forming complexes better able to traverse the biomembrane [17; 18; 19; 20; 21; 22]. Gels used as vehicles for active substances show a few advantages: their ease of preparation, limited amount of excipients, low overall cost of producing the finished formulation, increased resistance to moisture, organic nature that prevents the development of microbial contaminants, increased skin penetration and facilitated particle transport, generally low toxicity, and non-irritant nature when introducing hydrophilic and lipophilic compounds into the vehicle [23; 24; 25; 26; 27; 28]. Permeability is mostly determined by the skin barrier. The largest obstruction to the flow of molecules and the transfer of active substances is the _stratum corneum_, the outermost layer of the skin. Its chemical composition is mostly composed of ceramides, fatty acids, cholesterol and its derivatives, and minute quantities of phospholipids. The low solubility of silymarin in aqueous solutions, which leads to limited bioavailability and low absorption rates, is a major barrier to investigating new uses for it. A few studies have addressed the biodegradation of formulations containing silymarin, extract, and bio-ferment using activated sludge. The use of microorganism activity in our experiment is to assess the ability of formulations to degrade (in aerobic conditions) and determine whether they have a high degree of persistence in the environment. The OECD suggested a technique for testing the capacity for aerobic degradation, which is evaluated by measuring the CO\({}_{2}\) emitted. The formulations are categorized as easily or weakly biodegradable. This kind of vehicle is crucial for obtaining the bioavailability, high solubility, and permeability of active substances. Organogels and hydrogels are employed in this research study as vehicles. This study aims to find suitable vehicle(s) for silymarin, extract, and bio-ferment of milk thistle due to silymarin's poor skin permeability and low solubility. The originality of this study consists in its in-depth analysis of hydrogel and organogel formulations' biodegradation processes, as well as its evaluation of their environmental effects. The most appropriate vehicle(s) that are bioavailable and improve silymarin solubility and skin permeability can be chosen because of this investigation. Moreover, the use of the extract and bio-ferment from _Silybum marianum_ in cosmetic preparations increased the antioxidant potential of the obtained formulations. Our evaluation of the pig skin permeation of the main components of bio-ferment and extract, which are part of the silymarin complex, showed the influence of the type of carrier on the transdermal absorption and retention of silibinin and taxifolin in the skin.