Crosslinking of Chrysophyllum albidum gum with calcium chloride to enhance its physicochemical, compressional and tableting properties

This work aims to evaluate the effect of cross-linking on the physicochemical and compressional characteristics of Chrysophyllum albidum gum and the mechanical and release properties of its metformin tablet formulation. The physicochemical properties of the native (NCAG) and cross-linked Chrysophyllum albidum gum (CCAG) were evaluated using established methods while the compressional characteristics were determined using density measurements and indices of plasticity derived from Heckel and Kawakita equations. The mechanical properties were evaluated and the time taken for 50 % (T50) and 90 % (T90) drug dissolution were determined. CCAG had better flow, lower bulk density and a swelling capacity almost twice as that of the NCAG. The DSC results reveal no potential interaction between the gum and the cross linking agent. The compressional properties show that CCAG had higher Py but lower Pk values than NCAG. This suggests that CCAG induced slower onset of plastic deformation than NCAG but its overall amount of plastic deformation was higher. Metformin tablets containing CCAG gum were softer and more friable. All the tablets formulated with both NCAG and CCAG passed the disintegration test. Generally, tablets formulated with CCAG had shorter disintegration time. The T50 and T90 values show that the formulation containing 7.5 % w/w cross-linked Chrysophyllum albidum gum had the least dissolution time. The result suggests that cross-linking of the gum resulted in improved physicochemical and compressional properties and a better release profile of its metformin tablet formulation. These improved properties could be explored in tablet formulation and production.