RESUMEN
In this study, nitrogen-doped carbon quantum dots CQDs, synthesized from malic acid and EDTA, were encapsulated using sodium alginate. Different parameters affecting loading capacity (such as capsules' sizes, complexation solution's concentration and encapsulation method) were investigated. After that, ibuprofen (Ibu), taken as a model drug, was tagged by CQDs to form Ibu-CQDs adduct, and then encapsulated using sodium alginate. The results showed high values of loading capacity of CQDs, ibu and Ibu-CQDs capsules; 86.3%, 92% and 67%, respectively. It was proved that Ibu-CQDs release could be tracked using spectrofluorometry and UV-vis spectroscopy. The maximum release of Ibu-CQDs was 42% after 24 h. Temperature's effect on drug release was also studied and it was found that the best release was achieved at higher temperatures (40 °C), which corresponds to the illness state. Release medium's pH was also varied to simulate the pH of different parts of the gastrointestinal tract, and it was found that the best drug release can occur in the duodenum instead of the stomach. The current Ibu-CQDs capsules hold great promise for further studies in drug release and bioimaging applications.