title: Simultaneous estimation of amlodipine and atenolol in human plasma: a sensitive LC-MS/MS method validation and its application to a clinical PK study.
abstract: BACKGROUND
  A highly sensitive, specific and rapid LC-ESI-MS/MS method has been developed and validated for simultaneous quantification of amlodipine (AMD) and atenolol (ATL) in human plasma (200 µl) using AMD-d4 and ATL-d7, respectively, as an internal standard (IS) as per the regulatory guidelines.
  
  
  RESULTS
  The SPE method was used to extract the analytes and IS from human plasma. The chromatographic resolution of AMD, ATL and corresponding IS was achieved using an isocratic flow on a C18 column. The total chromatographic run time was 3 min. A linear response function was established for the range of concentrations 50-8000 pg/ml and 10-800 ng/ml for AMD and ATL, respectively, in human plasma.
  
  
  CONCLUSIONS
  The intra- and inter-day accuracy and precision values for AMD and ATL met the acceptance as per regulatory guidelines. The validated assay was applied to a fixed-dose combination of AMD and ATL (Adopin-AT(®)) PK study in humans.
authors.affiliation: College of Pharmaceutical Sciences, Andhra University, Visakhapatnam 530 003, AP, India.
authors.forename: Raja Reddy
authors.initials: RR
authors.lastname: Kallem
authors.forename: Ramesh
authors.initials: R
authors.lastname: Mullangi
authors.forename: Kishore Kumar
authors.initials: KK
authors.lastname: Hotha
authors.forename: L K
authors.initials: LK
authors.lastname: Ravindranath
authors.forename: Y N
authors.initials: YN
authors.lastname: Spoorthy
authors.forename: J V L N
authors.initials: JV
authors.lastname: Seshagirirao
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D017311:Amlodipine / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D001262:Atenolol / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D017311:Amlodipine; D001262:Atenolol