PHYSICO-CHEMICAL CHARACTERIZATION AND MODIFICATIONS OF SOME PLANTS MUCILAGE FOR INDUSTRIAL APPLICATIONS

Abstract

The mucilaginous components of Cissus populnea plant stem, Irvingia gabonensis (Wild-mango) seed and the Adansonia digitata fruit-pulp were effectively extracted and isolated to give high yield, off - white to brown, fluffy and voluminous powders named Cissus mucilage powder (CMP), wild-mango mucilage powder (WMP) and Adasonia fruit-pulp powder (APP) respectively. The chemical composition and elemental contents of the samples were examined by standard and validated techniques and methods. The samples were found to contain very high amount of carbohydrate and low amount of protein. Potassium, Calcium and magnesium were predominant macro-metals present in the CMP, WMP and APP samples respectively. The rheological studies of the samples indicated that they are pseudoplastic polymer, non-Newtonian and share thinning characteristic in nature at high shear rates. The thermal stability of the dry powders were determined by TGA and they were found to be stable to about 250 OC in inert environment and about 200 OC in the presence of oxygen. This implies that the dry powder can withstand industrial processes at high temperature to the limits mentioned. The peak decomposition temperature was 375 OC for CMP and APP while it was 325 OC for WMP. The low thermal stability of sample WMP was also implied from the decomposition activation energy of 8.87 kJ/mol and frequency factor (a measure of entropy) of 0.82 S-1. The structural properties of the sample were investigated by TLC, SEC, FTIR and GC-MS. The polymers appeared to be acidic polysaccharide complexes made of rhamnose, galactose, xylose, arabinose, glucose and glucuronic acids. The molecular weight distribution and confirmation in solution were determined by viscometry and the SEC. The samples were confirmed to be polydispersed with average molecular weight of 48.73 x 104 ± 4.38 (CMP), 31.36 x 104 ±5.70 (WMP) 46.73 x 104± 7.43 (APP) respectively. The molecular values obtained from SEC were not significantly different though lower. The chemical modifications adopted have enhanced the physicochemical properties such as viscosity and Swelling Index and hydration properties of the mucilage samples studied. The potential of the mucilage samples as pharmaceutical excipients were investigated by studying its effect as suspending agent in the formation of paracetamol suspension and as binding agent in the formulation of paracetamol tablets. Using simple validated techniques, the samples appeared to be a good suspending agents and flocculating agent and gave optimum stability profile in the concentration range of 2 to 6 % without the formation of compact cake. The developed paracetamol suspensions were as good as their corresponding commercial product and their physical stability and rheological properties appeared to be similar to those prepared with acacia and cashew gums. The hardness of the tablets for formulation prepared with the mucilage samples as binding agents were hard (>=4kg) and have comparable friability, disintegration time and dissolution time compared to those compounded with acacia and cashew gum were used. However, the tablet properties increase with the concentration of mucilage. The study has established the great potential of the samples as good raw material for industrial applications with inherent advantages.