Argan oil-in-water emulsions: Preparation and stabilization

Investigation of the synergistic effect of nonionic surfactants on emulsion resolution using response surface methodology

The production of crude oil is always accompanied by water production, which may create severe separation problems. It is important to understand the stabilization mechanism and parameters contributing to the formation of emulsion, specifically the synergy mixing of surfactants. These factors have not been studied primarily in previous studies. The main objective of the current work was to assess the influence of synergy mixing of nonionic surfactants, sorbitan monooleate (hexitol) and polysorbate 80 (glycol), which are mainly affecting the stability of oil-in-water emulsions. Several factors, such as the mixing rate, mixing time, and aging time of the studied emulsions were also investigated. Response surface methodology (RSM), and central composite design (CCD) were employed to design the experiments. Emulsion stability was measured through a static bottle test over a range of time (1–7 days) at a temperature of 60 °C. A model was established with a coefficient of determination value at 0.8814 and the highest emulsion stability achieved was 42.83%. The least water separation was observed at 0.5 v/v% hexitol, 1.5 v/v% glycol, 15 000 rpm mixing rate in 5 minutes, and seven-day ageing time to achieve ∼41.56% emulsion stability. The minimum emulsion stability of ∼25.0% was observed using 0.5 v/v% of sorbitan monooleate and polysorbate 80 at 5000 rpm of mixing rate in 15 min and under seven days of observation. The results also revealed that the mixing time and ageing time do not affect the stability of the prepared emulsions. Hexitol, mixing rate, synergy mixing of nonionic surfactants and polysorbate 80, and mixing speed significantly influence emulsion stability. The R² value of 88.14% verified that the model is well-fitted and the optimal values for the input variables were successfully obtained using RSM.

Response surface methodology (RSM) plot of formulation optimization showing the effect of variables on hexitol and glycol. Response surface plots of the predicted stability as a function of hexitol and glycol.

Floristic biodiversity, biogeographical significance, and importance of Morocco's Arganeraie Biosphere Reserve

The coastal and subcoastal areas of west-central Morocco (Safi to Draa River, the Souss Valley, and the southern part of the western High Atlas and northern and southern slopes of the western Anti-Atlas) are characterized by typical Infra-Mediterranean vegetation ranking them amongst the important of the remarkable borderlands of North Africa. The flora is determined by complex historical and environmental factors occurring since the Tertiary period. The originality of this sector is due to the presence of the argan tree (Argania spinosa (L.) Skeels), Moroccan gum (Acacia gummifera Willd), olive trees (Olea europaea L. subsp. maroccana (Greuter & Burdet) P. Vargas & al.), a thermophilic flora adapted to an arid climate with several endemic species. This flora constitutes the final barrier against the desert and is of environmental and socioeconomical interest. Leaves and fruits provide forage material, while wood is used for fuel. Argan fruits are collected for their oily constitutes and for nutritional, cosmetic, and medicinal properties. Additionally, many species of Argan ecosystems are used in medicine and cosmetics. Recognizing its ecological value and local economic importance, the Argan region was declared a UNESCO Biosphere Reserve in 1998. Despite their biogeographical, historical, and socioeconomic value, vegetation structures in west-central Morocco are vulnerable and threatened by human activities. They exhibit high levels of degradation due to increasing clearance, overgrazing, and overexploitation. The area requires high conservation priority and sustainable management strategies for key species and genetic diversity.

Enhancement of Chemical Stability and Dermal Delivery of Cordyceps militaris Extracts by Nanoemulsion

This study aimed to develop nanoemulsions for enhancing chemical stability and dermal delivery of Cordyceps militaris extracts. C. militaris was extracted by maceration and infusion. The extracts were investigated for cordycepin, phenolic, and flavonoid content. The antioxidant activity was investigated by in vitro spectrophotometric methods. The irritation profile was investigated by hen's egg-chorioallantoic membrane test. Nanoemulsions were developed using high-pressure homogenizer. C. militaris extract was incorporated into the nanoemulsion and investigated for safety, release profile, permeation, and skin retention. The results demonstrated that water extract (CW) contained the significantly highest content of cordycepin, phenolics, and flavonoids, which were responsible for antioxidant activity. CW was the most potent antioxidant. CW possessed comparable 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity and lipid peroxidation inhibition to l-ascorbic acid (96.9 ± 3.1%) and alpha-tocopherol (87.2 ± 1.0%). Consequently, ten mg/mL of CW was incorporated into nanoemulsions composing of sugar squalene, Tween® 85, and deionized water. Nanoemulsion, which had the smallest internal droplet size (157.1 ± 2.6 nm), enhanced the stability of CW, had no cytotoxicity effect and no skin irritation, released the most CW (0.9 ± 0.0% w/w after 24 h), and delivered the highest CW into the skin layer (33.5 ± 0.7% w/w). Therefore, nanoemulsion was suggested for enhancing the stability and dermal delivery of CW.