This document outlines quality control tests performed on suppositories, including: visual inspection of appearance, shape, color, and odor; weight uniformity testing; breaking/fragility tests to determine mechanical strength; disintegration testing using a basket rack apparatus; melting range/liquefaction time tests to ensure proper dissolution temperature; and assays to confirm average active ingredient content per suppository is within specified limits. The tests are designed to ensure suppositories meet standards for patient use and administration.

1. QUAITY CONTROL TESTS
FOR SUPPOSITORIES
Chapter # 5

2. Suppositories
 Solid dosage forms intended for
insertion into body orifices (rectum,
vagina, and urethra) where they melt,
soften, or dissolve and exert a local or
systemic effect.

3. QC TESTS OF
SUPPOSITORIES
1. Appearance/Visual examination.
2. Weight Uniformity.
3. Breaking/Fragility Test.
(Hardness/Mechanical
Strength/Crushing Test)
4. Disintegration Test.
5. Melting Range Test.
6. Liquefaction Time Test.
7. Assay of active ingredients

4. 1. Appearance/Visual
examination
 Colour & surface characteristics – are
assessed.
 Can be observed by splitting (cutting)
them longitudinally.
 This includes odor, colour, surface
condition and shape.

5. Shape
 Shape is checked to see – if it is
consistent.
Surface condition
 Checked for; brilliance, dullness,
mottling, cracks, dark regions, axial
cavities, air bubbles, holes, etc.

6. Colour
 Intensity, nature and homogeneity of the
colour should be verified.
Odor
 Verification of odor can prevent
confusion when similar suppositories are
being processed.
 Change in the odor may be – indicative
of a degradation process.

7. 2. Weight Uniformity
 Weigh all suppositories together = W.
Calculate average weight = W/20.
 Weigh 20 suppositories individually. w1,
w2, w3….w20
 Compare individual weights with average
weight in terms of % deviation.

8. Limits:
 Not more than 2 suppositories
◦ Deviation allowed from avg. wt = ±5%
 No suppository
◦ Deviation allowed from avg. wt = ± 10%.

9. 3. Breaking/Fragility Test
 Designed as a method for measuring
the fragility or brittleness of
suppositories.
 Suppositories – classified as brittle or
elastic;
◦ by evaluating mechanical force required
to break them.
 Measure the mass (in kgs) that a
suppository can bear without breaking.

10.  Good result = at least 1.8– 2 kg
pressure.
 Suppository is positioned in an upright
position in apparatus.
 Increasing weights – placed on it until it
loses its structure & collapses.
 Purpose;
◦ to verify suppository transportation &
handling &
◦ administration to patient.

11. Mechanical strength/breaking apparatus

12. Procedure;
1. Suppository is placed in the instrument.
2. Add 600 g; leave it for one min. (use a
stop watch).
3. If not broken, add 200 g every one min;
◦ until suppository is broken.

13. Calculations:
 Hardness of suppository – calculated by
adding weights together.
◦ If suppository broken before end of last min – last
weight cancelled.
 Different types of suppositories have different
breaking points.
 Value of breaking strength (point) of
suppository (in Kg);
◦ compared with value given in official monograph.

14. 4. Disintegration test
 Used to measure that whether
suppository will disintegrate within the
time limit;
◦ specified in official monograph.
 Apparatus used: B.P disintegration test
apparatus.

15. Apparatus
 Consists of cylinder of glass or rigid
transparent plastic;
◦ open at both ends
◦ height =60mm
◦ internal diameter = 52mm
◦ wall thickness = 8mm
 Cylinder – fitted internally with two
horizontal, parallel, perforated stainless
steel plates;
◦ held 30mm apart by 3 stainless steel metal
straps.

16.  Plates
◦ 50 mm in diameter
◦ perforated with 38 equally spaced holes;
 each 4 mm in diameter.
 Arranged in rings containing 6, 12, & 20 holes about a
central hole.
 Cylinder – suspended in water-bath;
◦ Water bath capacity = 4 litre
◦ containing water at temperature of 37±1 ºC.
◦ fitted with slow stirrer &
◦ device – hold cylinder, to be inverted every 10
minutes.
 (without its emerging from water).

17. Suppository Disintegration Apparatus
B.P

18. Method
 Take 3 suppositories.
 Place a suppository on the lower
perforated plate.
 Insert cylinder in water-bath,
 Operate apparatus for 30 minutes.
◦ or such other time as is specified in the
monograph.

19.  Suppository is disintegrated when:
1. completely dissolved or dispersed into
its component part, or
2. disintegration products have fallen
through perforated plate or raised to
surface of water, or
3. any solid matter remaining between
plates is completely melted & no longer
has a solid core.

20.  Repeat the test with two further
suppositories;
 If all three suppositories disintegrate
within 30 minutes,
◦ then the test is passed.
◦ unless otherwise specified in the
monograph.

21. 5. Melting Range Test
 Time taken by entire suppository to melt &
 Temperature at which suppositories melt;
◦ too much important for drug release.
 Melting range is the time taken by entire
suppository to melt,
◦ when immersed in constant temp. (37 ºC)
water bath.

22.  Melting range: time difference b/w initial
time when melting starts & final time,
when complete melting occurs.
◦ also called the macro melting range test.
 In contrast, micro melting range test is
melting range measured in capillary tubes
for fatty base only.

23. Apparatus
 Commonly used is a B.P suppository
disintegration apparatus.
 Suppository is constantly immersed in
constant water bath (37º), &
◦ Time for entire suppository to melt or
dispersed in surrounding water is
measured.

24.  Suppositories should melt at a
temperature below body temperature
(i.e. 37 ºC).

25. 6. Liquefaction Time Test
 Also called – Softening Time test
 Provides information on behaviour of
suppository;
◦ when subjected to a maximum temperature
of 37◦C.
 Test measures time required for
suppository to liquefy under pressures;
◦ similar to those found in rectum
(approximately 30 g) in presence of water at
37 ºC.

26.  In general, liquefaction should take no
longer than 30 minutes.

27. Apparatus & method
 Apparatus used – cellophane bag
liquefaction time apparatus;
◦ that simulates the in vivo condition.
 Consists of glass cylinder/ condenser;
◦ with external diameter of 50mm,
◦ narrowing down to 22mm at either end for a
length of 30mm.
 A dialysis membrane, i.e. cellophane tube
is tied to both ends of a condenser;
◦ with each end of tube open.

28.  Condenser – provided with 2 ports on one
side to circulate water at 37 ºC through the
apparatus,
◦ while one port on other side – hold thermometer for
temperature measurement.
 Water at 37 ºC – circulated through
condenser at such a rate;
◦ that lower half of cellophane tube collapses and
upper half gaps.

29. Liquefaction time apparatus using
cellophane bag

30.  When water temperature is stabilized
at 37 ºC suppository is drooped into it
so that it sits in middle of tube.
 Time is measured for suppository to
completely melt in tube.

31. 7. Assay of active ingredients
 Specific number of suppositories (10 or
20);
◦ crushed & mixed.
 Resulting mixture – subjected to assay
procedure described in official
monograph.
 Amount of active ingredient in
suppositories (taken for assay) is
determined.

32.  Then divided by no. of suppositories;
◦ to determine average amount of active
ingredients in single suppository.
 If result lies within range for active
ingredient;
◦ stated in the official monograph then test
is passed.