title: Simultaneous multivariate spectrophotometric analysis of paracetamol and minor components (diphenhydramine or phenylpropanolamine) in tablet preparations.
abstract: The use of multivariate spectrophotometric calibration is reported for the analysis of two decongestant tablets, where paracetamol is the principal component and diphenhydramine or phenylpropanolamine are the minor components. The resolution of these mixtures has been accomplished without prior separation or derivatisation, by using partial least-squares (PLS-1) regression analysis of electronic absorption spectral data. Although the molar ratios of paracetamol to the minor components were 38:1 and 25:1 respectively, the latter have been determined with high accuracy and precision, and with no interference from tablet excipients. PLS is able to take into account small deviations of paracetamol from linearity in the studied concentration range. The application of classical least-squares (CLS) analysis yields unsatisfactory results, due to the low absorbances of the minor components within the range where all components obey Beer's law.
authors.affiliation: Departamento de Química, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Paraje El Pozo, Santa Fe, Argentina.
authors.forename: H C
authors.initials: HC
authors.lastname: Goicoechea
authors.forename: A C
authors.initials: AC
authors.lastname: Olivieri
mesh_terms: D000082:Acetaminophen / Q000032:analysis*; D000465:Algorithms; D018712:Analgesics, Non-Narcotic / Q000032:analysis*; D000704:Analysis of Variance; D002138:Calibration; D004155:Diphenhydramine / Q000032:analysis*; D004338:Drug Combinations; D006634:Histamine H1 Antagonists / Q000032:analysis*; D007202:Indicators and Reagents; D016018:Least-Squares Analysis; D014663:Nasal Decongestants / Q000032:analysis*; D010665:Phenylpropanolamine / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets
chemical_list: D018712:Analgesics, Non-Narcotic; D004338:Drug Combinations; D006634:Histamine H1 Antagonists; D007202:Indicators and Reagents; D014663:Nasal Decongestants; D013607:Tablets; D010665:Phenylpropanolamine; D000082:Acetaminophen; D004155:Diphenhydramine