title: Sustained modelling ability of artificial neural networks in the analysis of two pharmaceuticals (dextropropoxyphene and dipyrone) present in unequal concentrations.
abstract: An improvement is presented on the simultaneous determination of two active ingredients present in unequal concentrations in injections. The analysis was carried out with spectrophotometric data and non-linear multivariate calibration methods, in particular artificial neural networks (ANNs). The presence of non-linearities caused by the major analyte concentrations which deviate from Beer's law was confirmed by plotting actual vs. predicted concentrations, and observing curvatures in the residuals for the estimated concentrations with linear methods. Mixtures of dextropropoxyphene and dipyrone have been analysed by using linear and non-linear partial least-squares (PLS and NPLSs) and ANNs. Notwithstanding the high degree of spectral overlap and the occurrence of non-linearities, rapid and simultaneous analysis has been achieved, with reasonably good accuracy and precision. A commercial sample was analysed by using the present methodology, and the obtained results show reasonably good agreement with those obtained by using high-performance liquid chromatography (HPLC) and a UV-spectrophotometric comparative methods.
authors.affiliation: Laboratorio de Control de Calidad de Medicamentos, Cátedra de Química Analítica I, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, 3000, Santa Fe, Argentina.
authors.forename: María S
authors.initials: MS
authors.lastname: Cámara
authors.forename: Félix M
authors.initials: FM
authors.lastname: Ferroni
authors.forename: Mercedes
authors.initials: M
authors.lastname: De Zan
authors.forename: Héctor C
authors.initials: HC
authors.lastname: Goicoechea
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis; D000996:Antitussive Agents / Q000032:analysis; D003198:Computer Simulation; D011431:Dextropropoxyphene / Q000032:analysis*; D004177:Dipyrone / Q000032:analysis*; D004563:Electrochemistry; D015394:Molecular Structure; D016571:Neural Networks, Computer; D017711:Nonlinear Dynamics; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000996:Antitussive Agents; D004364:Pharmaceutical Preparations; D004177:Dipyrone; D011431:Dextropropoxyphene