Novel spectral data for effervescent tablets according to shelf life.

To ensure the safety of pharmacotherapy, stability tests are carried out throughout the shelf life of all medicines. An interesting alternative to conventional methods of monitoring the quality of medicinal products is the measurement of reflectance and emissivity. The study aimed to assess the change in emissivity and reflectance for different types of effervescent tablets containing paracetamol and vitamin C. In the study, three types of effervescent tablets of the same product were analysed i.e., unexpired, expired, and stressed tablets. The accelerated aging test was performed for 7 days in a Solarbox 1500 chamber (Italy), in which the tablets were irradiated with simulated sunlight and a temperature of 26⁰C. The reflectance had similar values for both unexpired and expired tablets, but these were higher than for the stressed tablets. The emissivity analyses showed that tablets exposed to UV radiation for 7 days had the highest emissivity value of all types in the spectral range of 1.5-21.0 µm. Using a hyperspectral camera, the differences between the maximum and minimum reflectance values were assessed, as this may reflect the homogeneity of the sample. Homogeneity was similar for unexpired tablets, expired tablets, and tablets stressed for 3 days, they showed better homogeneity than tablets stressed for 7 days. It can be speculated that UV radiation increases the reflectance of the tablets and decreases the homogeneity of the tablets tested.