Influence of Polymers Diversity on the Dissolution Kinetics of Encapsulated p-Coumaric Acid in Oral Systems

<i>p</i>-coumaric acid is a natural phenolic compound with antioxidant activity, but its poor solubility and low bioavailability limit its practical use in oral formulations. The aim of this study is to evaluate how different polymers affect the dissolution and antioxidant properties of <i>p</i>-coumaric acid when incorporated into capsules and gels. Nine capsule compositions were prepared using poloxamer 407 (C1 group), sodium carboxymethyl cellulose (C2 group), chitosan (C3 group) and 5 hydrogels (G group) with the same polymers. The results indicate that <i>p</i>-coumaric acid is poorly soluble in aqueous solvents. The selected polymers modified the solubility of <i>p</i>-coumaric acid. The best solubility of <i>p</i>-coumaric acid was observed in mixtures containing 14.3% Poloxamer 407 (P407). The results showed that the polymers significantly affected the release kinetics of <i>p</i>-coumaric acid from the modeled capsules and gels. It was observed that capsules containing 14.3% P407 and gels with 14% P407 exhibited the best dissolution kinetics of <i>p</i>-coumaric acid. Antioxidant activity was strongest in formulations that released more <i>p</i>-coumaric acid. The results of this study confirm that the type and amount of excipients significantly affect the quality of capsules and gels. <i>p</i>-coumaric acid has the potential to be used in food supplements as a natural antioxidant, but further research is needed to improve its bioavailability and ensure safety.