Drug bioavailability evaluation
Solutions of seven drugs (Antipyrine, Propranolol hydrochloride, Hydrochlorothiazide, (±)-Sulpiride, and Ranitidine hydrochloride) were purchased from Shanghai Aladdin Biochemical Technology. Atenolol and Furosemide were purchased from Dalian Meilune Biochemical Technology. The drugs were prepared at a concentration of 2 μmol/ml in HBSS from Meilunbio. Prior to drug absorption evaluation, cells were washed twice with HBSS for 30 minutes. Then, 150 μL of the drug solution was added to the middle well, while 600 μL of HBSS was added to the lower well. After a 3-hour incubation, 500 μL of medium from the lower well was collected and centrifuged at 8000 rpm for 10 minutes. The supernatant was quantified by liquid chromatography (LC20A, Shimadzu, Japan) with a chromatographic column size of 250 mm*4.6 mm, 5 μm, C18. The injection volume was 10 μL. Antipyrine was detected at a wavelength of 254 nm, Propranolol hydrochloride at 223 nm, Verapamil at 278 nm, Hydrochlorothiazide at 270 nm, Ranitidine hydrochloride at 230 nm, Atenolol at 240 nm, (±)-Sulpiride at 230 nm, and Furosemide at 279 nm.