Cinnamyl O-amine functionalized chitosan as a new excipient in direct compressed tablets with improved drug delivery

The use of chitosan as a potential excipient in pharmaceutical formulations for the delivery of drugs produced via direct compression tableting has been investigated. Chitosan, N-cinnamyl substituted O-amine functionalized chitosan (cinnamyl-chitosan) and microcrystalline cellulose (MCC) were formulated, alongside acetaminophen as the active pharmaceutical ingredient (API), and magnesium stearate (Mg-St) as lubricant in a series of formulated blends. A control blend of MCC, acetaminophen (20 wt%) and Mg-St (0.5 wt%) was studied alongside two chitosan-bearing blends, containing 20 wt% chitosan and 20 wt% cinnamyl-chitosan separately. Particle size, shape and morphology of the raw powders were studied along with flowability of both raw powders and formulated powder blends. A single-punch tablet machine was used for tablet compaction. The relationship between tablet hardness and compression pressure was evaluated, while the plasticity factor (PF) and elasticity factor (EF) were derived from force-displacement curves. Disintegration and dissolution studies were also carried out to investigate the drug delivery potential of the blends. Blends containing chitosan and cinnamyl-chitosan possess good compaction properties with high elasticity due to their large particle sizes, and show excellent dissolution properties, releasing >80% API within 30 min. With good mechanical strength and superior drug delivery performance, in addition to its enhanced antibacterial and antioxidative effect gained though chemical modification, cinnamyl-chitosan exhibits potential to be used as a new cost-effective pharmaceutical excipient in direct compression tableting.