Physicochemical Characterization of Sucrose And Formaldehyde Modified-Starches From Maize, Wheat And Rice For Pharmaceutical Use

Background: Starches have been shown to be important across various disciplines such as the pharmaceutical industries, food industries and also paper industries. Starch is basically a mixture of polymers consisting of a-D-glucose as the monomeric unit. The goal of this study is to modify the native starches which are gotten from Zea mays, Triticum estivum, and Oriza sativa through cross-linking using sucrose and formaldehyde at different concentrations, and assessing the utilisabilty of the modified starches as potential excipients [binder] for tabletting of Paracetamol tablets. Method: Starch was extracted from Maize, Wheat and Rice grains and defatted. A confirmatory test was carried out on the extracted starch. The starches were treated with ethanol and crosslinked with varied concentrations of sucrose and formaldehyde. Further characterizations were carried out such as the determination of moisture content, bulk and tapped densities, effect of electrolyte on swelling behavior, viscosity and pH . Results: Maize and rice starches cross linked with 2.5 % sucrose gave the least percentage moisture content. The batches cross-linked with 40% formaldehyde showed the highest moisture content. The densities (bulk and tapped) of maize wheat and rice starches showed a reduction with the increasing concentration of the cross-linking agent for sucrose, which is the reverse case for formaldehyde. The different concentrations of sucrose and formaldehyde cross-maize, wheat and rice starches had pH values between 4.50 and 5.52. The onset and end set of the glass transition temperatures were varied for all the starches modified with formaldehyde. The melting peak temperatures obtained indicated that the formaldehyde-modified rice starch had significantly lower melting temperature than those of wheat and maize starches.Conclusion: The result of all the studies carried out shows that the different concentrations of sucrose and formaldehyde had effects on the various qualities of the native starches used and that the chemical agents used also had effects on the original molecular conformations of the native samples though the amorphous and crystalline structures were still present. Cross linking agents made the starch molecule more surfaces active by causing a change in conformation of the molecules at the interface hence an increase in viscosity. The starches were denatured by the cross-linking agents and this could improve their suitability for human consumption as food, cosmetic materials and even drug [as excipients].