Supplement I to the Japanese Pharmacopoeia Fourteenth Edition

Supplement I, JP XIV
General Tests, Processes and Apparatus
1375
Add the following:
73. Determination of Bulk and
Tapped Densities
Determination of bulk and tapped densities is a method to
determine the bulk densities of powdered drugs under loose
and tapped packing conditions respectively. Loose packing
is deˆned as the state obtained by pouring a powder sample
into a vessel without any consolidation, and tapped packing
is deˆned as the state obtained when the vessel containing
the powder sample is to be repeatedly dropped a speciˆed
distance at a constant drop rate until the apparent volume of
sample in the vessel becomes almost constant. The bulk density
is expressed in mass per unit apparent volume of powder
(g/mL). Because the bulk density is one of the measures of
packing properties, compressibility and ‰ow properties, and
is dependent on the ``history'' of the powder, it is essential
to report the bulk density to specify how the determination
was made.
Bulk density
The bulk density is an apparent density obtained by pouring
a powder sample into a vessel without any consolidation.
The determination of bulk density is achieved by measuring
the apparent volume of a powder sample having a known
mass in a graduated cylinder (Method 1) or by measuring the
massofpowderinavesselhavingaknownvolume(Method
2).
Method 1 (Constant mass method)
Unless otherwise speciˆed, pass a quantity of sample
su‹cient to complete the test through a 1000-mm (No.16)
screen to break up agglomerates that may have formed during
storage. Weigh accurately about 30 g of test sample, and
pour it into a dry 100-mL graduated glass cylinder (readable
to 1 mL). Carefully level the powder without consolidation,
if necessary, and read the unsettled apparent volume, V 0 ,to
the nearest graduated unit. Calculate the bulk density r B by
the formula:
r B = M V 0
r B : Bulk density by constant mass method (g/mL)
M :Massofpowdersample(g)
V 0 : Apparent volume of powder sample (mL)
Record the average of 3 determinations using 3 diŠerent
powder samples. If a 30-g sample is too large to determine,
adjust the mass of sample so as to provide an apparent
volume of 60 – 100 mL.
Method 2 (Constant volume method)
Unless otherwise speciˆed, pass a quantity of sample
su‹cient to complete the test through a 1000-mm (No.16)
screen to break up agglomerates that may have formed during
storage. Allow an excess of sample powder to pour into
the measuring vessel having the volume of V and mass of
M 0 . Carefully scrape excess powder from the top of the vessel
by smoothly moving across it the edge of a slide glass or
other tool. Remove any material from the sides of the vessel,
and determine the total mass M t . Calculate the bulk density
r B by the formula:
r B = M t - M 0
V
r B : Bulk density by constant volume method (g/mL)
M t : Total mass of powder and measuring vessel (g)
M 0 : Mass of measuring vessel (g)
V : Volume of measuring vessel (mL)
Record the average of 3 determinations using 3 diŠerent
powder samples.
Tapped density
Tapped density is an apparent density obtained by
mechanically tapping a measuring vessel containing a powder
sample. The determination of tapped density is achieved
by measuring the apparent volume of a powder sample having
a known mass in a vessel after tapping (Method 1) or by
measuring the mass of powder in a vessel having a known
volume after tapping (Method 2).
Method 1 (Constant mass method)
Unless otherwise speciˆed, pass a quantity of sample
su‹cient to complete the test through a 1000-mm (No.16) or
a710-mm (No.22) screen to break up agglomerates that may
have formed during storage. Weigh accurately about 100 g
of test sample, and pour it into a 250-mL graduated glass
cylinder (readable to 2 mL) without consolidation. If it is not
possible to use 100 g, proceed according to the same procedure
as that described above by using a 100-mL graduated g-
lass cylinder (readable to 1 mL). It is essential to select appropriate
masses of the cylinder support, holder and cylinder
so as to ensure the dynamic stability of the apparatus
during tapping. After attaching the glass cylinder containing
the powder sample to the tapping apparatus, carry out tapping
under the measuring conditions (tapping rate and drop
height) speciˆed for each apparatus.
Unless otherwise speciˆed, repeat increments of 50 taps or
1 minute until the diŠerence between succeeding measurements
is less than 2z, and determine the ˆnal apparent
volume, V f . Calculate the tapped density r T by the formula:
r T = M V f
r T : Tapped density by constant mass method (g/mL)
M :Massofpowdersample(g)
V f : Final apparent volume of sample after tapping (mL)
Record the average of 3 determinations using 3 diŠerent
powder samples.
Method 2 (Constant volume method)
Unless otherwise speciˆed, pass a quantity of sample
su‹cient to complete the test through a 1000-mm (No.16)
screen to break up agglomerates that may have formed during
storage. Attach a supplementary cylinder to the stainless
steel measuring vessel having a known mass of M 0 and a
volume of V (Fig.1),andthenpouranexcessofthesample
into the vessel. After setting up the vessel in an adequate tap-