title: Error structure for the HPLC analysis for atenolol, metoprolol and propranolol: a useful weighting method in parameter estimation.
abstract: Three reversed-phase high performance liquid chromatography (HPLC) methods with UV detection were developed and fully validated for the quantification of three beta-blockers: atenolol, metoprolol and propranolol. After validation, error structures for the HPLC analysis were established using a convenient and practical procedure. The mean percentage of relative standard deviation (RSD) of the experimental concentrations (C), were less than 4.29% for proportionality and less than 3.68% for precision for any of the drugs, which allowed the quantitation of beta-blockers assayed at concentrations in the range 25-0.78 micrograms.ml-1. The error structures for the HPLC analysis were: SD (micrograms.ml-1) = 5.02 x 10(-2) C for atenolol, SD (micrograms.ml-1) = 4.55 x 10(-2) + 0.63 x 10(-2) C - 7.58 x 10(-6) C3 for metoprolol and SD (micrograms.ml-1) = 2.73 x 10(-2) C - 3.49 x 10(-4) C2 for propranolol. The reciprocal of the square of the SD of the drug concentrations measured within the calibration curve could be used as weighting methods in parameter estimation by non-linear regression.
authors.affiliation: Department of Pharmacy, Faculty of Pharmacy, University of Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Modamio
authors.forename: C F
authors.initials: CF
authors.lastname: Lastra
authors.forename: E L
authors.initials: EL
authors.lastname: Mariño
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000032:analysis* / Q000737:chemistry; D001262:Atenolol / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005069:Evaluation Studies as Topic; D008790:Metoprolol / Q000032:analysis* / Q000737:chemistry; D011433:Propranolol / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D000319:Adrenergic beta-Antagonists; D001262:Atenolol; D011433:Propranolol; D008790:Metoprolol