Glacial acetic acid

Acetazolamide (ACZ) and polyethylene glycol (PEG8000) were purchased from Sigma–Aldrich (Madrid, Spain). Dimethylsulfoxide (DMSO), sodium acetate, sodium hydroxide, and dichloromethane (DCM) were obtained from Panreac (Madrid, Spain). Acetonitrile and glacial acetic acid were purchased from Lab-Scan (Gliwice, Poland). Propylene glycol (PG) was purchased from Abaran Materias Primas S.L. (Madrid, Spain). Ultrapure water was produced in the laboratory by a Milli-Q Water Purification System (Millipore Iberica SA, Madrid, Spain).

PLA Luminy L105, injection grade with D-lactide content lower than 1% (melt flow index (MFI): 30 g/10 min (2.16 kg 190 °C) were kindly supplied by Total Corbion PLA Co. Ltd., Thailand. PLA Ingeo 3251D, injection grade with 1.4% D-lactide content (MFI: 35 g/10 min (2.16 kg 190°C) was purchased from NatureWorks LLC, USA. Potassium dimethyl 5-sulfoisophthalate (also known as LAK-301) from Takemoto Oil & Fat Co., Japan was used as received. 5-sulfoisophthalic acid (HSIPA) was purchased from Wako Pure Chemical Industries Ltd. Methanol, Glacial acetic acid and Sodium hydroxide was obtained from RCI Labscan Ltd., Thailand.

The light air-cured leaves of N. tabaccum were received from Maejo Tobacco Experiment Station, Chiang Mai, Thailand, under the TOAT organization. The plant voucher specimen (No. 0023267) was deposited at the Herbarium of the Faculty of Pharmacy, Chiang Mai University (CMU), and authenticated by the CMU staff botanist. Chloroform, ethanol, glacial acetic acid, methanol, and sodium acetate were purchased from RCI Labscan Limited (Bangkok, Thailand). Sodium carbonate and sodium hydroxide were purchased from Merck (Darmstadt, Germany). ethanol (99% v/v) was purchased from Liquor Distillery Organization (Bangkok, Thailand). Trimethylamine was purchased from Loba Chemie Pvt, Ltd. (Mumbai, India). Nicotine standard was purchased from Sigma-Aldrich (St. Louis, MO, USA). Hydroxypropyl methylcellulose E15 (HPMC E15, AnyCoat^®-C AN15) was purchased from Lotte Fine Chemical Co., Ltd. (Seoul, Korea).

2,2′-Azinobis 3-ethylbenzothiazoline-6-sulphonate (ABTS), 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH), 2,4,6-tripyridyl-s-triazine (TPTZ), 6-hydroxy-2,5,7,8-tetramethyl chroman-2-carboxylic acid (Trolox), ammonium thiocyanate (NH₄SCN), ferrous chloride (FeCl₂), kojic acid, L-tyrosine, linoleic acid, oleanolic acid, ferrous sulfate (FeSO4), potassium persulfate (K₂S₂O₈), sodium acetate trihydrate (CH₃COONa.3H₂O), sodium chloride (NaCl), sodium sulfate anhydrous (Na₂SO₄), and tyrosinase from mushroom (EC 1.14.18.1) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Acetic acid, hydrochloric acid, ethanol, calcium chloride (CaCl₂), chloroform, de-ionized (DI) water, dimethyl sulfoxide (DMSO), glacial Acetic acid, petroleum ether, and sulfuric acid (H₂SO₄) were purchased from RCI Labscan Co., Ltd. (Bangkok, Thailand).

Materials: polyvinyl alcohol (PVA) and polyethylene glycol-1000 (PEG) were purchased from Xilong Scientific Co., Ltd. (Shantou, China). Chitosan (CS) and polyvinylpyrrolidone (PVP K30) were purchased from Shanghai Zhanyun Chemical Co., Ltd. (Shanghai, China). Glacial acetic acid (AA) was purchased from RCI Labscan (Bangkok, Thailand). All materials were used as received.
Synthesis of CS/PEG/PVA/PVP: To make a polymer blend, polymer stock solutions had to be made. The stock polymer was synthesized by adding dried 1 g PEG, 1 g PVA, and 1 g PVP in 50 mL DI water individually. Meanwhile, 0.5 g of CS was added to 48.5 mL of DI water and 1.5 mL of AA. The polymer stocks were stirred and heated at 80 °C for 1 h, or until the polymers were completely dissolved in water. Then, each stock polymer was mixed with additional DI at the volume shown in Table 1 and Table 2 in 15 mL plastic falcon tubes. Then, the mixture was shaken in an orbital incubator at 35 °C and 150 rpm for 20 h. All the experiments were repeated 3 times.