RESUMO

The use of multivariate spectrophotometric calibration for the simultaneous determination of dexamethasone and two typical excipients (creatinine and propylparaben) in injections is presented. The resolution of the three-component mixture in a matrix of excipients has been accomplished by using partial least-squares (PLS-1). Notwithstanding the elevated degree of spectral overlap, they have been rapidly and simultaneously determined with high accuracy and precision (comparable to the HPLC pharmacopeial method), with no interference, and without resorting to extraction procedures using non-aqueous solvents. A simple and fast method for wavelength selection in the calibration step is used, based on the minimisation of the predicted error sum of squares (PRESS) calculated as a function of a moving spectral window.

Assuntos

Creatinina/análise , Dexametasona/análise , Parabenos/análise , Calibragem , Cromatografia Líquida de Alta Pressão , Indicadores e Reagentes , Análise Multivariada , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta

RESUMO

The use of multivariate spectrophotometric calibration for the simultaneous determination of several active components and excipients in ophthalmic solutions is presented. The resolution of five-component mixtures of phenylephrine, chloramphenicol, antipyrine, methylparaben and thimerosal has been accomplished by using partial least-squares (PLS-1) and a variant of the so-called hybrid linear analysis (HLA). Notwithstanding the presence of a large number of components and their high degree of spectral overlap, they have been determined simultaneously with high accuracy and precision, with no interference, rapidly and without resorting to extraction procedures using non aqueous solvents. A simple and fast method for wavelength selection in the calibration step is presented, based on the minimisation of the predicted error sum of squares (PRESS) calculated as a function of a moving spectral window.