Abstract:
The processing technique for production of alpha and microcystalline cellulose using
Sorghum bicolor and Andropogon gayanus as starting materials was established. The
effect of reagent type and concentration, pH, temperature, digestion and bleaching time
on the quality and yield of the powdered cellulose grades &as studied. Acute toxicity
test on the derived polymers was investigated using albino mice. The physicotechnical
properties of the new polymeric materials were studied. A Carver hydraulic
hand press was used to determine the compression and compaction characteristics of
the cellulose products. The reworking potentials of the pure excipents in addition to
ihe critical excipient concentr&ions of SOMCC or AMCC in blends containing drugs
were determined. Formulations of acetaminophen, ascorbic acid and metronidazole at
polymer concentrations of 30, 33.3 and 33.3% respectively were compressed using
STC Tablet Machine Model THP (Shanghai).
., ,, . 4 . r . .#* , , . a
The yield of the white cellulose grades, sorghum microcrystalline cellulose (SOMCC)
and Andropogon microcrystalline cellulose (AMCC) was 32 and 34.5% respectively of
I, . .,.
the dried and powdered grass. Both SOMCC and AMCC had LD,, >1000mg/kg.
Starch and Dextrins were absent, pH was in the range of 5.8 to 6.5 and moisture
content was between 4.6-6.4%. The a-cellulose grades were approximately 4 times
vii
bulkier than the corresponding MCC grades, while hydration capacity (H,) ratio is
approximately 2: 1. Swelling capacity (S,) of the polymers obeyed a derived equation
, S,=(d,/n~.V ,)-1 where V, is volume of swollen material, d, is particle density and
m is weight of dry material. S, of the a-cellulose grade was approximately twice that
of the microcrystalline form in each case. The tensile strength profiles of the
polymers showed that compact strength is in the order SOMCC > AMCC > Avicel
pH 101. The determined yield pressures (P,) were 152.27 and 195.08MNm-2 for
SOMCC or AMCC. The P, of Avicel PHlOl was 151.24 MNm-2 which is quite
close to that of SOMCC. The percentage recompressibility was in the order SOMCC
'3 Avicel > AMCC. Acetaminophen, ascorbic acid and metronidazole were all found
to be compatible with SOMCC, AMCC or Avicel PH 101. A 25 to 40% w/w
concentration of AMCC, SOMCC, or Avicel PHlOl is required to produce noncapping
tablets of acetaminophen or ascorbic acid at compression pressure of 63.4 to
03.6 MNm-2 while that of metronidazole is 30-40 % at 93.4 to 124 MNrn-2.
., ,..,., r, .,' ,.'V$ ' 1:ormulations of these drugs were found to exhibit good tablet characteristics and
drug contents were within acceptable ranges. The t,, of acetaminophen tablets
Ior~nulated with the excipients and determined after 6 months of storage was in the
, I - .-
order SOMCC = AMCC < Avicel PHlOl, while that of metronidazole was Avicel
1'1-1 101 < SOMCC = AMCC. The findings in this work indicates that the two grades
of MCC can find wide application in pharmaceutical and allied industries.
