title: Bioequivalence of nifedipine softgel and capsule in healthy Chinese volunteers by liquid chromatography-mass spectrometry.
abstract: The study aimed to compare and evaluate the bioequivalence of Calcigard-10 softgel and Adalat 10 capsule in healthy Chinese volunteers in a randomized, two-way cross over study design with a washout period of 7 days. A sensitive and reproducible electro-spray ionization liquid chromatography-mass spectrometry (ESI-LCMS) assay was developed and validated to determine nifedipine in human plasma using nitrendipine as internal standard. Nifedipine and nitrendipine were extracted from plasma using liquid-liquid extraction with methylene chloride as extraction solvent. The separation was performed by a Diamonsil ODS column (150 x 4.6 mm, 5 microm). The mobile phase was consisted of acetonitrile-5 mM ammonium acetate (52:48, v/v), delivered at flow rate of 1 mL/min. The 90% confidence intervals for the ratio values of logarithmic transformed Cmax and AUC were calculated to evaluate the bioequivalence of two preparations. The values of Cmax (92.3-112.7%), AUC0-t (84.5-95.1%) and AUC0-inf (84.4-95.5%) are within the interval criterion of 70-143% for Cmax and 80-125% for AUC. The Calcigard-10 softgel and Adalat 10 capsule are bioequivalent.
authors.affiliation: Institute of Clinical Pharmacology, Qilu Hospital of Shandong University, Jinan 250012, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Hao-Jing
authors.initials: HJ
authors.lastname: Song
authors.forename: Fan-Long
authors.initials: FL
authors.lastname: Bu
authors.forename: Chun-Min
authors.initials: CM
authors.lastname: Wei
authors.forename: Gui-Yan
authors.initials: GY
authors.lastname: Yuan
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Liu
authors.forename: Ben-Jie
authors.initials: BJ
authors.lastname: Wang
authors.forename: Rui-Chen
authors.initials: RC
authors.lastname: Guo
mesh_terms: D000328:Adult; D044466:Asian People; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D018592:Cross-Over Studies; D004304:Dosage Forms; D006801:Humans; D008297:Male; D009543:Nifedipine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D013810:Therapeutic Equivalency
chemical_list: D002121:Calcium Channel Blockers; D004304:Dosage Forms; D009543:Nifedipine