Characteristics of Commercial Effervescent Tablets Using Selected Pharmacopeial and Novel Analytical Methods

Abstract

In the present study, we aimed to determine whether the shelf life of effervescent tablets may be assessed during storage using total directional hemispherical reflectance (THR). We also analyzed selected pharmacopeial parameters of the tablets and used X-ray microtomography to assess the internal structure of the tablets. Two types of effervescent tablets of one commercial product containing magnesium and vitamin B6 (expired and unexpired) were analyzed. In addition, randomly selected unexpired and expired tablets were dried in a vacuum oven for 24 h at 50 °C. The expired effervescent tablets disintegrated in a significantly shorter time than the unexpired tablets (68 s vs. 83 s, p = 0.016). The remaining pharmacopeial parameters did not differ between the two types of tablets. We observed that expired effervescent tablets showed lower mean values of THR in five spectral ranges, which indicates that a greater amount of radiation beam was transmitted into their inner structure than for unexpired tablets. The density of the inner structure assessed on the microtomographic scans differed significantly between all the analyzed tablets (p < 0.001). The highest mean density was observed in the case of the unexpired tablets dried in a vacuum oven (1.273 g/cm3), while the lowest density was observed in the case of the expired tablets (1.261 g/cm3). The expired tablets had a larger pore diameter compared to the unexpired tablets (0.095 mm vs. 0.074 mm, respectively; p = 0.007). Additionally, the percentage of porosity was higher in the expired tablets compared to the unexpired tablets (p < 0.001).