Sodium citrate hydrate

Pyrogallol (C₆H₃(OH)₃, > 99%), sodium citrate hydrate (C₆H₅Na₃O₇·2H₂O, > 99%), polyvinpyrrolidone (PVP, > 99%), methanol (CH₃OH, > 99.8%), sodium hydroxide (NaOH, > 97%), potassium hydroxide (KOH, > 85%), lead (II) nitrate (Pb(NO₃)₂, > 99.9%), and nitric acid (HNO₃, 69%) were purchased from Wako Pure Chemical Industries, Ltd. All chemical were used as received without further purification. Deionized water with a specific resistance of 18.2 MΩ cm was obtained by reverse osmosis followed by ion exchange and filtration.

1,2-Distearoyl-sn-glycero-3-phosphocholin (DSPC; COATSOME MC-8080), 1,2-distearoyl-sn-glycero-3-phosphoglycerol, sodium salt (DSPG-Na; COATSOME MG-8080LS), and 1,2-distearoyl-rac-glycero-3-methylpolyoxyethylene, for which the PEG molecular weight is 2000 (PEG2000-DSG; SUNBRIGHT GS-020), were gifts from NOF Co., Ltd. (Tokyo, Japan). Paclitaxel, cholesterol, sucrose, lactic acid, sodium lactate, chloroform, and methanol were purchased from FUJIFILM Wako Pure Chemical Corp. (Osaka, Japan). Methyl cellulose 15, methyl cellulose 400, sodium citrate hydrate, and macrogol 4000 were also purchased from FUJIFILM Wako Pure Chemical Corp. (Osaka, Japan). Cell counting kit-8 was purchased from Dojindo Laboratories (Kumamoto, Japan). RPMI-1640 medium “Nissui” was obtained from Nissui Pharmaceutical Co., Ltd. (Tokyo, Japan). In addition, 2-mercaptoethanol was purchased from Nakalai Tesque (Kyoto, Japan). All other chemicals were commercially obtained products of reagent grade.