Sodium phosphate monobasic monohydrate

Ketoprofen USP was purchased from Letco Medical (Decatur, AL, USA). Eudragit^® E PO was received as a gift sample from Evonik Degussa Corporation (Parsippany, NJ, USA). Calcium chloride dihydrate, magnesium chloride hexahydrate, sodium chloride, potassium carbonate, sodium phosphate dibasic heptahydrate, sodium phosphate monobasic monohydrate, and all other chemicals used in this study were of analytical grade and purchased from Fisher Scientific (Norcross, GA, USA).

Two neutral compounds (BOH and THBP), HPLC-grade acetonitrile (ACN), ammonium formate (99%, NH₄COOH), formic acid (95%), acetic acid (99%), dimethyl sulfoxide (99%, DMSO) and TM-β-CD (90%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). The other two neutral compounds (TFAE and TSO) were purchased from TCI AMERICA (Tokyo, Japan). Sodium acetate (NaOAc), sodium hydroxide (NaOH) (50% w/w), sodium phosphate dibasic heptahydrate and sodium phosphate monobasic monohydrate were purchased from Fisher Scientific (Fair Lawn, NJ, USA). Triply deionized (DI) water used in this experiment was obtained from Barnstead Nanopure II water system (Barnstead International, Dubuque, IA, USA).
The reagents ω-undecylenyl alcohol, 2-bromoethylamine hydrobromide, pyridine anhydrous, L-leucinol, L-alaninol, L-valinol, L-isoleucinol, (1S,2R)-ephedrine hydrochloride, formic acid (≥95), formaldehyde (37% (wt/wt) solution in water) used for the synthesis of ILs were all purchased from Sigma-Aldrich (St. Louis, MO, USA). Triphosgene was obtained from TCI AMERICA (Tokyo, Japan). Sodium sulfate anhydrous and sodium bicarbonate were purchased from Fisher Scientific (Fair Lawn, NJ, USA).

Copovidone (Plasdone™ S-630), hydroxypropylcellulose (Klucel™ ELF, EF, & HF), ethylcellulose (Aqualon™ N7), Polyplasdone™ XL & XL-10 and Sildenafil Citrate were kindly gifted by Ashland Specialty Ingredients (Wilmington, DE). Mannitol (Pearlitol™ 300-DC) was donated by Roquette America Inc. (Keokuk, IA). Sucralose was gifted from JK Sucralose (Jiangsu Provence, China). Monoammonium Glycyrrhizinate (Magnasweet®) was donated by Mafco Worldwide CORP. (Camden, NJ). Butylated hydroxytoluene (BHT) was purchased from Sigma-Aldrich (St. Louis, MO). Magnesium Stearate was purchased from Spectrum Laboratory Products Inc. (Gardena, CA.). Calcium carbonate, magnesium oxide, calcium chloride dihydrate, magnesium chloride hexahydrate, sodium chloride, potassium carbonate, sodium phosphate dibasic heptahydrate, sodium phosphate monobasic monohydrate as well as all solvents used in these studies (analytical grade methanol, acetonitrile & water), were purchased from Fisher Scientific (Norcross, GA). Natural & artificial mint flavoring was gifted by Flavors of North America (Carol Stream, IL).

The maltose binding protein (MBP) was obtained from MyBioSource (San Diego, CA). Human full-length β-2-microglobulin (β2m) was purchased from Lee Biosolutions (Maryland Heights, MO). Lysozyme from chicken egg white and the following chemicals were obtained from MilliporeSigma (St.Louis, MO): DL-dithiothreitol (DTT), diethylpyrocarbonate (DEPC), dimethyl(2-hydroxy-5-nitrobenzyl)sulfonium bromide (HNSB), epigallocatechin gallate (EGCG), guanidine hydrochloride (GuHCl), imidazole, iodoacetamide, maltose monohydrate, MOPS, MOPS sodium salt, N,N’,N” triacetylchitotriose (NAG₃), L-tryptophan, and urea. Acetonitrile, copper sulfate (CuSO₄), formic acid, potassium acetate, sodium phosphate, sodium phosphate monobasic monohydrate, HPLC grade water, and a 1 M Tris buffer (pH 8) stock solution were all purchased from Fisher Scientific (Fair Lawn, NJ). Centricon molecular weight cutoff (MWCO) filters were obtained from Millipore (Burlington, MA). Sequencing grade modified trypsin and sequencing grade chymotrypsin were obtained from Promega (Madison, WI).

1,2-dimyristoyl-sn-glycero-3-phospho-(1’-rac-glycerol) (sodium salt) (DMPG, T_m= 23°C), 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (sodium salt) (DMPS, T_m= 35°C), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC, T_m= 24°C) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE, T_m= 63°C) were purchased in powder form (>99% purity, Avanti Polar Lipids, Inc, Alabaster, AL, USA). Lipid stock solutions of desired concentrations (<5 mg/ml) were prepared by dissolving the powders in 9:1 volume % chloroform: methanol. Sodium nitrate (NaNO₃, 99.995% purity, Sigma, St. Louis, MO, USA) was used to prepare monovalent electrolyte solutions used in surface force measurements and low salt zeta potential measurements. Sodium phosphate dibasic heptahydrate (Na₂HPO₄.7H₂O, >99+% purity, ACROS Organics, NJ, USA), sodium phosphate monobasic monohydrate and sodium chloride (NaH₂PO₄.H₂O, 99.2% purity, NaCl, 99.9% purity, Fisher Scientific, Waltham, MA, USA) were used to prepare the phosphate buffer for zeta potential measurements. Water used in experiments was purified with a MilliQ Gradient water purification system with a resistivity of 18.0 MΩ·cm.