Study Set Content:
150 – 1000
Coarse powder range
1000 – 3360
Average granule size
>1000
Very coarse
355 – 1000
Coarse
180 – 355
Moderately fine
125 – 180
Fine
90 – 125
Very fine
Other methods that can be used to determine particle size
Optical Microscopy
Sieving
Sedimentation
Particle Volume Measurement
Importance of particle size in a certain formulation to improve:
Release and dissolution.
- Absorption and drug action.
- Physical stability.
- Dose uniformity
is the ratio of the mass of an untapped powder sample and its volume including the contribution of the inter-particulate void volume
Bulk density of a powder
units of bulk density of powder
g/ml =(g/cm3)
\= 1000 kg/m3
are dependent upon the preparation, treatment and storage of the sample, i.e. how it was handled.
bulking properties of a powder
he bulk density of a powder is determined by measuring the
volume of a known mass of powder sample
The bulk density of a powder is determined by measuring the volume of a known mass of powder sample, that may have been passed through a sieve
into a graduated cylinder
or by measuring the
mass of a known volume of powder
or by measuring the mass of a known volume of powder that has been passed through a
volumeter
or by measuring the mass of a known volume of powder that has been passed through a volumeter into a
cup or a measuring vessel.
A uniform particle size distribution ensures a uniform
dissolution rate.
Reducing particle size
Communition
rubbing or grinding in a mortar and pestle; used for hard, fracturable powders
Trituration
