Multivariate calibration on designed mixtures of four pharmaceuticals

Abstract

The use of multivariate calibration for estimating the concentration of mixtures by electronic absorption spectroscopy, as illustrated by quinidine, labetalol, alprenolol and isoxsuprine, recorded at five concentration levels, is considered. The importance of designing calibration experiments is described, including weighing and dilution schemes, consideration about spectral overlap and the properties of the design matrix. Several calibration methods are applied. A function for weighted regression is proposed. The ability to predict small weighing errors is studied.