Chlorzoxazone

Chlorzoxazone (lot: LC90O72) was purchased from J&K Scientific Corporation (Beijing, China). Caffeine (lot: 20071224) was obtained from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Rat CYP1A2 and CYP2E1 ELISA Kits (lot: 20180511, 20180321) were purchased from Fangcheng Beijing Technology Co., Ltd. (Beijing, China). Biochemical reagents kits were purchased from Jiangxi Tekang Technology Co., Ltd.: alanine phosphatases (lot: 1707110), transaminases GPT (lot: 1707136), transaminases GOT (lot: 1707132), total bilirubin (lot: 1707113), direct bilirubin (lot: 1707128), indirect bilirubin (lot: 1707126), total protein (lot: 1707131), albumin (lot: 1707127), globulin (lot: 1707108), creatinine assay kit (lot: 1707129), and uric acid (lot: 1707125). HPLC-grade methanol (lot: 20170507) was purchased from Shandong Yuwang Company Inc. (Jinan, China). All other chemicals and solvents were obtained from commercial sources at the highest grade available. HEPES were obtained from AMRESCO Company Inc. (Boise, USA). RNAiso Plus (lot: 9109), Prime-Script™ RT Reagent (Lot: K1622), and SYBR premix EX Taq™ II (lot:AK6401) were obtained from Takara (Kyoto, Japan). Primers used for real-time PCR were synthesized by Takara.

Phenacetin, bupropion, tolbutamide, dextromethorphan, midazolam, chlorzoxazone, and the diazepam (all purity> 98%) that used as internal standards (ISs) were purchased from J&K Scientific Ltd. (Beijing, China). Vonoprazan was purchased from Beijing Sunflower Scientific Ltd. (Beijing, China). Hydroxybupropion and hydroxymidazolam were purchased from Sigma-Aldrich (St Louis, USA). Dextrorphan, hydroxytolbutamide, hydroxychlorzoxazone, and 4-acetamidophenol were purchased from Toronto Research Chemicals (Toronto, Canada). Reduced nicotinamide adenine dinucleotide phosphate (NADPH) was acquired from Roche Pharmaceuticals Ltd. (Basel, Switzerland). Ultra-pure water was produced by Milli-Q, a reagent-standard water purification system (Millipore, Bedford, USA). Acetonitrile and methanol that of high performance liquid chromatography (HPLC) grade were obtained from Merck Company (Darmstadt, Germany).

(±)-Doxazosin mesylate [(±)-DOX], (+)-doxazosin mesylate [(+)-DOX], and (−)-doxazosin mesylate [(−)-DOX] standards (>99.9% purity) were provided by the New Drug Research and Development Center of the North China Pharmaceutical Group Corporation (Shijiazhuang, China). β-Nicotinamide adenine dinucleotide phosphate hydrate (NADP), glucose-6-phosphate dehydrogenase from Baker’s yeast (S. cerevisiae), glucose-6-phosphate, prazosin (internal standard, IS), phenacetin, tolbutamide, and human CYP enzymes (CYP3A4, CYP2D6, CYP2C19, CYP2C8, CYP1A2, CYP2E1, and CYP2C9) were purchased from Sigma-Aldrich (St Louis, USA). Dextromethorphan hydrobromide, paclitaxel, and testosterone were provided by TCI Shanghai (Shanghai, China). Chlorzoxazone and omeprazole were purchased from J&K Chemical (Beijing, China). Heparin sodium injection was provided by the Jiangsu Wanbang Biochemical Pharmaceutical Group Co., Ltd. (Xuzhou, China). Human and rat liver microsomes were purchased from BD Gentest (Franklin, USA). Tris base and MgCl₂ were purchased from Tianjin Yongda Chemical Reagent Co., Ltd. (Tianjin, China). Ultrapure water was prepared by Thermo Scientific Nanopure Water Purifier (Waltham, USA). HPLC-grade methanol and acetonitrile were purchased from Thermo Fisher Scientific (Ottawa, ON, Canada). All the other chemicals were of analytical grade.