COMPRESSIONAL AND MECHANICAL PROPERTIES OF NATIVE AND MODIFIED STARCHES OF Solenostemon rotundifolius COMPARED WITH GELATIN AND Zea mays
Keywords:
Compressional, Mechanical, Solenostemon rotundifolius starch, Maize starch.Abstract
The aim of this study is to determine the compressional and mechanical properties of native and
modified starches of Solenostemon rotundifolius compared with gelatin and Zea mays. 500 mg
compacts of Solenostemon rotundifolius starch (SRS), Water – prepared pregelatinised starch
(PGSW), Alcohol – dehydrated pregelatinised starch (PGSA), Gelatin (GLT) and Maize starch
(MZS) were made using a hydraulic press at various tableting pressures (56.6-169.9MNm-2) and
investigated for deformation characteristics and tensile strength. The ability of a powder bed to be
compressed and consequently be reduced in volume is referred to as compression, which depends
on the mechanical strength of the material. It plays an important role in the manufacturing of
tablets. The ranking order for mean yield pressure, PY was PGSA>MZS>GLT>SRS>PGSW; total
plastic deformation, DA, was SRS<GLT<PGSW<MZS<PGSA showing that SRS and PGSW
deforms plastically with fast onset of deformation while PGSA has tendency to show
fragmentation before plastic deformation. The tensile strength results for SRS (0.22-0.70MNm-2),
PGSW (0.29-0.79MNm-2), PGSA (1.76-1.82MNm-2) and MZS (0.71-1.50-1.44MNm-2) which
were in agreement with compression studies showed that SRS and the modified starches produced
harder and more compact tablets compared with Maize starch B.P. Hence, SRS, PGSW and PGSA
could be useful in formulation of tablets with desired mechanical properties.
