Abstract:
Background: Starch is one of the most extensively used pharmaceutical excipients with minimal
processing that could meet most of the requirements for excipients. Starch is the main component
in yams and they are cultivated as tuber crops in many areas of Sri Lanka.
Objectives: To characterize the necessary physicochemical parameters of starch extracted from
yams of Solenostemon rotundifolius (Innala) and Dioscorea pentaphylla (Katu Ala) in expounding
its appropriateness as excipients compared to maize starch BP
Methods: Yams of S. rotundifolius and D. pentaphylla were unpeeled, sliced, air-dried, and
powdered. Starches were extracted by mixing powdered yams with distilled water (1:2 w/v),
filtering, and drying the precipitate at 40°C. The extracted starches and commercially available
maize starch BP were characterized considering physicochemical properties such as pH, particle
size, bulk, tapped and true densities, Hausner’s ratio, Carr’s index, angle of repose, hydration
capacity, moisture sorption capacity, clarity, turbidity, Infrared spectroscopy analysis, and
microscopic analysis. Statistical analysis was performed using SPSS version 23.0.
Results: There was no significant difference between S. rotundifolius starch and maize starch BP
in terms of bulk density, tapped density, Hausner’s ratio, and turbidity while D. pentaphylla starch
did not report a significant difference in bulk density, clarity and turbidity compared to maize
starch BP (p>0.05). Both yam starches exhibited fair flow properties while maize starch BP had
poor flow properties. All these three starches exhibited identical IR spectra. Starch granule shapes
of D. pentaphylla, S. rotundifolius and maize starch BP were oval, dome and polyhedral,
respectively as per the microscopic analysis.
Conclusions: Both S. Rotundifolius and D. pentaphylla starches reported certain favourable
parameters compared to maize starch BP. Therefore, modifying extracted starches and extraction
techniques would enhance their properties.
