Synthesis, characterization, and functional properties of a novel sodium carboxymethyl starch obtained from matured seeds of

Background and objective

is an indigenous but underutilized legume crop in Nigeria. The aim of this study was to extract, purify, chemically modify, and characterize for its material and functional properties the starch from matured seeds of and determine its suitability as an excipient in solid oral dosage formulations.
Materials and methods
Starch was extracted, purified, and subjected to carboxymethylation using modified methods. Micromeritic and rheological properties of the starch products were evaluated using differential scanning calorimetry, powder radiograph diffraction (XRD), Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis techniques, which were used to characterize the preparations. Granules were prepared using the method of wetting and massing. The bulk properties, solubility, and the disintegrant properties were evaluated in isoniazid capsules and tablets.
Results and discussion
The results show good compressibility and excellent flow of the modified starch. The solubility of the modified starch was increased by 2–10 folds, whereas the swelling capacity of the native starch was increased up to 9.0–16 times. Both differential scanning calorimetry and XRD results have shown a reduction of crystallinity, whereas the Fourier-transform infrared spectroscopy indicated formation of carbonyl functional group and absence of interactions. Scanning electron microscopy revealed eruption and coalescence of starch granules after modification. XRD showed decreased thermal stability, and thermogravimetric analysis showed product decomposition at lower temperatures than the native starch. Disintegration was found to be faster with lower concentration of carboxymethylated starches.
Conclusion
The study concludes that derivatization of carboxymethylated starch from seed yielded starch products with unique functional properties that could be explored for the formulation of controlled-release systems.