Edible Gels with Cranberry Extract: Evaluation of Anthocyanin Release Kinetics

The bioactive compounds found in cranberry fruit are natural antioxidants, and their consumption reduces the risk of diabetes, cardiovascular disease, cancers, and urinary tract infections. Oral gels with cranberry fruit extract are a promising product that can ensure accurate dosage and release of the active compounds and are suitable for people with dysphagia. The aim of this study was to determine the effect of polymeric materials on the dissolution kinetics of cranberry fruit anthocyanins from gel formulations. Gel formulations were prepared using freeze-dried cranberry fruit extract with different gelling excipients: chitosan (G1-G3), sodium carboxymethylcellulose (G4-G6), and sodium carboxymethylcellulose combined with carbomers (G7-G9). The dissolution test showed that the release of anthocyanins from gel formulations G1-G6 and G9 was most intense within the first 10 min, with little change in the anthocyanin content of the acceptor medium afterwards. For the formulations based on carboxymethyl cellulose and carbomers G7 and G8, the amount of anthocyanins released into the acceptor medium gradually increased, which prolonged the release time of the active compounds. The test for the release of anthocyanins from the semi-solid systems through a hydrophilic membrane revealed that within the first hour, the total amount of anthocyanins released from the modeled gel formulations (G1-G9) was within the range of 6.02%-13.50%. The 1% chitosan (G1) gel formulation released the fastest and highest amount of anthocyanins (70% within 6 h). The other formulations showed a slower release of anthocyanins, and after 6 h, the amount of anthocyanins released from formulations G2-G9 was <57%.