Determination of paracetamol in intact tablets by use of near infrared transmittance spectroscopy

Near infrared transmittance spectroscopy was used to determine the analgesic paracetamol in a pharmaceutical preparation commercially available as tablets. Spectra were recorded on a dedicated instrument that measures the transmission of intact tablets over the wavelength range 600-1900 nm. Spectral data were processed by using two multivariate calibration methods, viz. stepwise multiple linear regression (SMLR) and partial least-squares regression (PLSR). The analgesic contents provided by the two calibration methods were comparable and differed by less than 1% from the reference (UV spectrophotometric) value. The calibration graphs constructed to determine the mean paracetamol content were used to analyse content uniformity in the tablets. (C) 1999 Published by Elsevier Science B.V. All rights reserved.