Glycerol gly

High- (average Mw: 1,500,000; batch number: 918VYH) and medium- (average Mw: 1,250,000; batch number: 889EMW) molecular-weight chitosan (CH) (≥90% degree of deacetylation) were purchased from Glentham Life Sciences LTD (Corsham, UK). Glycerol (Gly) (≥99.5%) was supplied by Merck (Darmstadt, Germany), whereas citric acid (CA) (Ph.Eur.8.0; batch number: BX1994654), PEG 400 (Ph.Eur.9.0; Lot No. EC1418626), and lidocaine as lidocaine hydrochloride monohydrate (Ph.Eur.9.0; Lot No. DG8019793; MW: 288.8 g/mol; pKa (amine): 7.9; solubility in water: 50 mg/mL) were purchased from Molar Chemicals Ltd. (Hungary). Enalapril as enalapril maleate (MW: 492.5 g/mol; pKa (acid): 3.0; pKa (amine): 5.5 (in salt form) or 8.0 (in base form); solubility in water: 25 mg/mL) was received as a gift from Richter Gedeon (Budapest, Hungary). Mucin Type II from porcine stomach was purchased from Sigma-Aldrich (Shanghai, China). Distilled water was used as a solvent in the preparation of the solutions.

PGA, purchased from Xi’an Fengzu Biological Technology Co., Ltd. (Xi’an City, Shaanxi province, China), was dissolved in distilled water (0.4 g/mL) and, when required, extensively dialyzed against distilled water until a conductivity of 9 mS/cm was reached. Spectra/Por^®3 dialysis membranes (standard regenerated cellulose tubing, 29 mm diameter; molecular weight cut-off 3.5 kDa) were from Sigma Chem. Co. (St. Louis, MO, USA). Glycerol (GLY, about 87%) was purchased from the Merck Chemical Company (Darmstadt, Germany). All other chemicals and solvents used in this study were analytical-grade commercial products.

Argan seeds were purchased from a local market in Marrakech (Morocco). Chemicals for electrophoresis were from Bio-Rad (Segrate, Milano, Italy). The reagents for cell viability testing, Dulbecco’s modified Eagle’s medium (DMEM), fetal bovine serum (FBS), penicillin, streptomycin, and fungizone, were purchased from M&M Biotech (Naples, Italy). Sodium hydroxide, hydrochloric acid, and glycerol (GLY) were purchased from Merck Chemical Company (Darmstadt, Germany). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and N-hexane (99%) were purchased from Sigma Chemical Co. (St. Louis, MO, USA). MaterBi^® and low density polyethylene (LDPE) films were from local market shopping bags (Naples, Italy). All other chemicals and solvents used in this study were of analytical grade unless specified.

4-methylimidazole (purity > 98%), 1-methylimidazole (1-MeI) and glycerol (GLY) were purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany). Ethylene glycol (EG), sodium chloride (NaCl), sodium hydroxide (NaOH), hydrochloric acid (HCl) and all other reagents (analytical grade) were purchased from Merck. Nitrogen gas (Sabalan Co., Tehran, Iran) with 99.999% purity was used for gas flow of GF-HS-SDME system. Stock solution of 4-MeI and 1-MeI were prepared by dissolving 1.0 g of each compound separately in 1 L of ethanol to obtain a concentration of 1000.0 mg L⁻¹. All solutions were kept at 4 °C in a dark place when not in use, being stable for 3 months [21 (link)].

The materials used for this study were: gelatin (Berthelet, Laval, QC, Canada), glycerol (GLY) (analytical grade, Sigma-Aldrich, Saint Louis, MO, USA), hydrophilic bentonite (Nanomer^® PGV, Sigma-Aldrich, Saint Louis, MO, USA), lignocellulosic microfiber from Agave angustifolia Haw, obtained from the method developed by Hernández et al. [14 (link)], potassium hydroxide, hydrochloric acid and silica gel (Hycel, Jalisco, Mexico), sodium bromide and sodium chloride (Fermont, Monterrey, Mexico). Distilled water (DW) was used in all formulations.

Hemp oilseed cakes, a generous gift of prof. Daniele Naviglio, were purchased from Consorzio Goji Italia (Andria, Italy). Egagropili sea balls were collected in the sardinian Poetto beach (Cagliari, Italy) and stored at 4 °C until used. Sodium hydroxide, hydrochloric acid, sodium chlorite, acetic acid glacial, potassium hydroxide, sulfuric acid and glycerol (GLY) were purchased from Sigma Chemical Co (St. Louis, MO, USA). All other chemicals were of analytical grade.