## 4 Discussion
Such formulations can be obtained by modifying their method of preparation or by adding microcapsules and solid dispersions to the formulation [13; 14; 28; 29; 30]. In the present study, we used a commercial formulation that contains citric acid and sodium carbonates as acidity regulators; magnesium carbonate, fructose, cyclamates, and saccharin as sweeteners; aroma; vitamin B6; and riboflavin as a dye. Magnesium is one of the essential ions for the functioning of the body and plays a vital role in the functioning of the brain, heart, and skeletal muscles. It is a cofactor involved in more than 600 biochemical reactions, and its deficiency can result in serious dysfunction [31; 32]. Decreased levels of magnesium have been shown to be associated with anxiety, depressive disorders, and mood changes [33]. It has been observed that vitamin B6 acts as a cofactor in more than 160 enzyme reactions [34]. A previous experimental study based on a rat model showed that the administration of high doses of vitamin B6 increased magnesium concentration [35]. Sodium bicarbonate, included in the formulation of effervescent tablets, facilitates the disintegration of the tablet and enhances gastric emptying, resulting in the API reaching the site of absorption faster and appearing in the blood in a shorter time [1; 36; 37; 38; 39]. In addition, the contact time of the drug with the gastric mucosa and the possibility of its inactivation in an acidic environment are reduced [40]. Many studies have proven significant differences in the pharmacokinetic parameters of API released from an effervescent tablet compared to conventional oral preparations [41; 42; 43]. Unfortunately, effervescent components are hygroscopic and moisture-labile, and storing tablets at temperatures above 25 \({}^{\circ}\)C accelerates the decomposition of bicarbonate into carbonate. A stable production process allows obtaining a pharmaceutical product that retains its quality characteristics throughout its shelf life. During the production of tablets or other drug forms, data can be obtained using various types of devices used to control and monitor the process. These measurements can be carried out using different methods: \"at-line\", \"on-line\", and \"in-line\". Each manufactured batch of tablets is tested for compliance with the requirements of the specification. Of the entire batches, only randomly selected samples are tested through the most often time-consuming tests. The assessment of the quality of tablets includes the following tests: organoleptic, dimensions, content of medicinal substances and possibly decomposition products, disintegration time, resistance to abrasion and crushing of tablets, and microbiological purity. The use of spectroscopic techniques may allow obtaining new spatial information about the sample. Particularly noteworthy are modern, non-destructive analytical techniques, including NIR, Raman spectroscopy, X-ray fluorescence, terahertz spectroscopy, and others. Previously, such studies were conducted [11; 27; 44; 45], although they are still not standard procedures. In addition, using these methods, it is possible to control the quality of the samples from a given batch in a non-destructive, non-invasive, fast, and time-saving manner. These methods can also be used during the storage of a pharmaceutical product to gain new knowledge about the degradation processes occurring in the tablet, enabling the data obtained from them to be correlated with data from pharmacopeial tests. We found a few studies analyzing effervescent tablets during storage [12; 13; 14; 46; 47]. [PERSON] et al. [46] analyzed effervescent tablets containing alendronate sodium and vitamin D3 and observed no significant change in physiochemical properties after storage at various temperatures and humidity conditions for one month and then for three months. The hardness and solution time of the tablets showed a tendency to be higher after three months of storage, but the changes were insignificant.