Effects of carboxymethylated gum obtained from Entandophragma angolense tree on the compressional and release properties of ibuprofen tablets

The incorporation of modified polymers in drug formulations is primarily due to their low toxicity, affordability, availability, compatibility with biological membranes, economic feasibility and bio-degradability.This study investigated the compressional and release characteristics of ibuprofen tablet formulations containing natural and modified Entandophragma angolense gum. Entandophragma angolense gum (ENTA) was extracted and modified by carboxymethylation to yield CENTA. Ibuprofen tablets containing varying binder concentrations (2.5-10% w/w) of ENTA and CENTA (compared with gelatin BP) were formulated by wet granulation. Crushing strength (CS) and friability (FR) were used in assessing the mechanical properties of the tablets, while disintegration and dissolution times accounted for drug release parameters. Density measurements, Kawakita equations and Heckel plots were used to assess the compressional properties of the formulations. The results were analysed using ANOVA at ɑ0.05. Generally, there was a direct relationship between the concentration of the polymers and the CS of the tablets, while an inverse relationship was observed for FR. The CS ranked ENTA > CENTA > gelatin BP. Carboxymethylation of ENTA enhanced drug release (t30% and t80%). Formulations containing CENTA had a slower and faster onset of plastic deformation; mean yield pressure (Py), ranked ENTA > CENTA > gelatin BP. A measure of the rearrangement phase at the early stages of compression (DB) was highest for CENTA at all concentrations. CENTA compared favourably with gelatin BP and showed better mechanical and release characteristics than ENTA. Also, CENTA shows good potential as a binder in fast disintegrating ibuprofen tablets, especially when incorporated at low concentrations.