Directional Hemispherical Reflectance in the Analysis of Expired and Unexpired Tablets Containing Nifuroxazide—The Results of a Pilot Study †

Abstract

This study aimed to assess the possible usage of total directional hemispherical reflectance (DHR) in terms of the stability of tablets during storage. Expired and unexpired coating tablets containing nifuroxazide were analyzed. Reflectance was determined in seven wavelength bands using an SOC-410 Directional Hemispherical Reflectometer (Surface Optics Corporation, USA). Significantly lower (p < 0.001) mean total DHR was observed for expired tablets in comparison to unexpired tablets for all the spectral bands, apart from one in the infrared range (i.e., 1000–1700 nm). The results indicated that total reflectance lowered during the storage in all spectral bands, except infrared.