Development of a Raft-Forming System Using Plantago major Mucilage as a Natural Polymer for Sustained Gastric Release of Artemisia annua L. Phenolic Extract.

Background/Objectives: Alginate-based rafts are typically used for antacids and provide a floating, gastric-retaining gel in the stomach that acts as a barrier to the entrance of stomach acid into the esophagus. Various technologies have been developed to enhance the sustained release of drugs and bioactive components and overcome challenges associated with gastric retention. Modern methods, such as the alginate raft, not only function as an antacid in gastroesophageal reflux disease but also can serve as a delivery system that extends the drug release time in gastric medium. This study assessed the effects of biocompatible natural polymers, such as Plantago major mucilage (PMM), on raft formation instead of synthetic polymers, such as Carbomer. Methods: PMM was substituted in the raft formulation at concentrations of 0.5% and 1%. The formed rafts were analyzed for their physicochemical, mechanical, and structural properties. To evaluate the sustained release potential of the optimized raft formulation, the aqueous extract of Artemisia annua L. was incorporated into coconut protein nanoparticles and loaded into the optimized raft at three different concentrations of 1%, 2%, and 3%. Results: The rafts formulated with PMM 0.5% revealed excellent stability of the suspension, as well as improved physicochemical properties of the developed rafts compared to the raft that included Carbomer. The results illustrated that the inclusion of PMM in the raft system enhances antacid capacity, swelling percentage, resilience time, strength, and a stiffer gel with a higher G'. Conclusions: The optimized PMM raft was able to prolong the in vitro release of phenolic extracts and reach the cumulative release of less than 30% after 6 h.