Physicochemical Properties, Colloidal Stability, and Encapsulation Efficiency of Lecithin-Based and Chitosan-Coated Liposomes Loaded with Cinnamomum zeylanicum Bioactives

Cinnamomum zeylanicum (C. zeylanicum) is rich in bioactives, such as cinnamaldehyde and phenols, which are susceptible to thermal degradation, volatilisation, and oxidative deterioration during processing and storage, thereby reducing chemical stability and limiting bioavailability. Encapsulation using lecithin and chitosan-based systems mitigates these instabilities by forming a protective barrier against oxygen, light, and heat while enhancing structural stability. In this study, freeze-dried extracts of C. zeylanicum were encapsulated into lecithin-based primary liposomes (PL) and chitosan-coated secondary liposomes (CH/L). The coating of liposomes with chitosan improves the liposome stability, mucoadhesion, and provides protection in the gastric pH while facilitating electrostatic bonding with the biological membrane. The high compatibility and low toxicity of chitosan also make it a suitable carrier in food and nutraceutical applications. The formed liposomes were characterised for particle size, polydispersity index, zeta potential, encapsulation efficiency (EE), and storage stability over 8 weeks. CH/L showed superior EE (89.027%) compared to the PL (84.154%; p < 0.05). The particle size, polydispersity index, and zeta potential of the cinnamon-loaded lecithin-based primary liposome (CZ-PL) upon formation were 161.93 nm, 0.13, and −37.597 mV. In comparison, those of the cinnamon-loaded chitosan-coated liposomes (CZ-CH/L) were 591.7 nm, 0.27, and +28.17 mV. The particle size of CZ-PL and CZ-CH/L was 175.90 and 588.60 nm after 8 weeks of storage. The TEM confirmed the spherical morphology of the liposomes. The differential scanning calorimetry analysis demonstrated the disappearance of the characteristic cinnamon melting peak and shifts in liposomal transition temperatures, confirming successful encapsulation. FTIR analysis showed reduction or disappearance of characteristic cinnamon fingerprint peaks and slight band shifts, indicating successful encapsulation and non-covalent interactions, including hydrogen bonding and electrostatic effects, within the liposomal systems. These findings imply that lecithin-based and chitosan-coated liposomes could be employed to successfully carry C. zeylanicum bioactives.