Functional and Mucoadhesive Properties of Native and Modified Eucalyptus Tereticornis Gum in Oral Chlorpheniramine Maleate Tablets

Abstract: As excipients, mucoadhesive polymers increase the resident times of drugs in the mucin/epithelial surface, which is significant for drugs with short half-lives. Native (ETG) and acetylated Eucalyptus tereticornis gum (AETG) were incorporated as excipients in directly compressed uncoated and matrix chlorpheniramine maleate tablets, and evaluated for their physicochemical, compressional, release functionalities and mucoadhesive properties. The gums were characterized using photo micrography, rheology, density and compression measurements, swelling capacity (27±0.50C and 80±0.50C) and FTIR spectroscopy as criteria, and incorporated as excipients (2.5-10.0%w/w) in chlorpheniramine maleate tablets for their compression and release properties, while the mucoadhesive properties of tablet matrix (10-80% w/w gum) were evaluated using pig and cow ilea in 0.1MHCL (pH 1.2). ETG and AETG were spherical to angular in shape. AETGhad higher breakdown (907±0.02cP), peak (930±0.01cP) and final (24±1.06cP) viscosities, but lower set back viscosity (3.50±0.03cP), with higher angle of repose, bulk and tapped desities, but lower Carr’s index and Hausner’s ratio. The ETG had lower deformation characteristics as evidenced by the higher Pk values and lower swelling capacities at both temperatures. FTIR spectra indicated significant presence of more functional groups at 757.13cm-1 and 427.66cm-1 in AETG due to strong aromatic N-H bond and C-S stretching of aliphatic halogenated compounds. Formulations containing AETG disintegrated and dissolved faster and showed better mucoadhesive profiles in pig ileum. Acetylation of Eucalyptus tereticornis gum exhibited better functional properties and generally showed better compressional, release and mucoadhesive properties when compared to the unmodified gum.