Sodium alginate/carboxymethyl chitosan/gelatin-naringenin pH-responsive hydrogel beads for oral delivery of traditional Chinese herbal medicines.

Stomach disorders are a common category of digestive system diseases. With the increasing emphasis on traditional medicine, the use of herbal medicines in treating gastric diseases has attracted much attention. However, direct administration of herbal medicines with short half-life leads to low drug utilization. To address this problem, pH-responsive composite hydrogel beads consisting of sodium alginate/carboxymethyl chitosan/gelatin-naringenin (SA/CMCh/Gel-Nar) were designed in this study to encapsulate decocted herbal saddle decoctions (AZD) for use as sustained-release medications for gastrointestinal disorders. The SA/CMCh/Gel-Nar hydrogel beads have high drug loading capacity, strong adhesion (98.33 % retention), and excellent pH-responsive sustained-release properties. In SGF, 39 % of the drug was released within 2 h, ensuring rapid therapeutic efficacy, while in SIF, the remaining 61 % was gradually released within 23 h. With excellent antimicrobial efficacy (>93.4 %) and high biosafety (cell viability >97.21 %), these hydrogel beads provide a promising and safe platform for sustained drug delivery in the gastrointestinal tract.