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Effect of particle size of
granules on some mechanical properties of paracetamol
tablets
Eichie, F. E.* and
Kudehinbu, A. O.
Department of Pharmaceutics and Pharmaceutical
Technology, University of Benin, Benin City, Nigeria.
*Corresponding author. E-mail:
eichiefe@yahoo.com.
Accepted
27 August, 2009 |
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Solid
dosage forms are invariably multiparticulate systems of
heterogenous particle size distribution. The purpose of this
study was to investigate the effect of particle size
distribution of paracetamol granules on some tablet
mechanical properties of paracetamol tablets. Granules were
formed by wet massing paracetamol powder (200 g) with 20%
(w/w) of maize starch mucilage as binder. Resulting granules
were classified into different size fractions (212 - 1700
µm) by sieve analysis and samples of granules from the
various size fractions were compressed into tablets of
weight 500 ± 4.3 mg, diameter 12.3 ± 2.3 mm and thickness
3.6 ± 1.2 mm, using a single punch tablet machine at a
compression pressure load of 7 arbitrary units on the load
scale. The tablets were equilibrated for 24 h before
evaluation. Tablet mechanical parameters evaluated were
packing fraction (Pf), tensile strength (T),
particle density, porosity and friability. The results
showed that T values and friability index decreased slightly
from 1.48 MNm-2 to 1.35 MNm-2 and 1.77
to 0.93%, respectively, following an increase in the granule
sizes from 212 to 1700 µm. These differences were, however,
not statistically significant. The packing fraction (Pf)
of the tablets increased from 0.853 to 0.960 significantly
following an increase in granule size from 212 to 1700 µm.
The indication is that there is a higher degree of
consolidation of the compacts formed from larger granules as
a result of plastic deformation and fragmentation than those
from smaller granules. The study showed that varying the
granule size distribution in a powdered bed affects some
tablet mechanical characteristics. The implication of this
is that the granule sizes should be controlled during
tableting and/or filling into capsule in order to avoid
weight and content variation while ensuring that only
tablets with desirable mechanical characteristics are
formed.
Key
words:
Particle size, paracetamol granule, tensile strength,
friability, tablet characteristics. |
