TITLE
Effects
of different ingredients on the characteristics of suspension formulation
OBJECTIVES
To know
the effects of using different amount of Tragacanth to the formulation of
Suspension.
INTRODUCTION
Suspension formulation is
a type of dispersed system where the solid molecules do not dissolve
homogenously in the liquid phase. In chemistry, a suspension is a heterogeneous fluid containing solid particles
that are sufficiently large for sedimentation. Usually they must be larger than
1 µm. Suspension is classified as coarse suspension where the particle diameter
is more than 1 µm or colloidal suspension where the particle size is less than
1 µm. In pharmaceutics, suspension is used to improve the stability, the taste
and the bioavailability of the active ingredient. Unlike colloids, suspensions
will eventually settle. Colloids and suspensions are different from solutions,
in which the dissolved substance (solute) does not exist as a solid, and
solvent and solute are homogeneously mixed. The physical stability of a
pharmaceutical suspension is the condition in which the particles do not
aggregate and in which they remain uniformly distributed throughout the
dispersions. In order to achieve this ideal situation the suspension should
have additive, which are added to achieve ease in re-suspension by a moderate
amount of agitation.
The internal phase (solid) is dispersed
throughout the external phase (fluid) through mechanical agitation, with the
use of certain excipients or suspending agents. Suspensions are classified on
the basis of the dispersed phase and the dispersion medium, where the former is
essentially solid while the latter may either be a solid, a liquid, or a gas.
A good suspension must
stay in homogenous state after being shaken, be easy to pour out from the
container and having a uniform solid particle size and also attractive taste
and texture. Precipitation formed from the storage must be easily dispersed
again after shaking and the dispersion formed must be homogenous.
Normally,
suspension composed of active ingredient (solid phase) dispersed in the liquid
carrier, wetting agent, flavoring agent and coloring agent. Wetting agent (eg:
Tragacanth) is used to reduce the surface tension between solid particle and
liquid. Suspending and thickening
agents are added with the objective to increase apparent viscosity of
the continuous phase thus preventing rapid sedimentation of the dispersed
particles. The selection of the type and concentration of a suspending agent
depends on sedimentation rate of dispersed particles, pourability and
spreadibility. The ideal suspending agent should have a high viscosity at
negligible shear, that is during shelf storage and it should have a low
viscosity at high shearing rates which is it should be free flowing during
agitation, pouring and spreadibility. A suspending agent that is thixotropic as
well as pseudoplastic should prove to be useful as it forms a gel on standing
and becomes fluid when shaken. They include natural polysaccharides (Acacia,
Tragacanth), Semi-synthetic polysaccharides (Sodium Carboxymethylcellulose),
Clays (Aluminium Magnesium Silicate) and synthetic agents (Carbomer).
Pseudoplastic substances like tragacanth show these desirable qualities. In cases
of combination use of suspending agents like bentonite and CMC dispersions are
both pseudoplastic and thixotropic.
MATERIAL AND APPARATUS
Apparatus:
Weighing instrument
Weighing boat
Mortar and pestle
150 ml plastic bottle
50 ml measurable cylinder
200 ml measurable cylinder
1 set of 1 ml pipette and pipette bulb
1 centrifugator tube 15 ml
100 ml beaker
Centrifugator
Viscometer
Ingredients:
Chalk
Tragacanth
Concentrated Peppermint Water
Syrup BP
Double-strength chloroform water
Distilled water
PROCEDURE
1. 1 formulation of Pediatric
Chalk Mixture (150 ml) was prepared by the following formulation.
Chalk 3 g
Tragacanth (referred
to the Table 1)
Concentrated
Cinnamon Water 0.6 ml
Syrup BP 15
ml
Double
Strength Chloroform Water 75 ml
Distilled Water, q.s. 150 ml
Table 1
Pediatric Chalk Mixture
|
Group
|
Tragacanth (g)
|
I
|
1, 5
|
0.0
|
II
|
2, 6
|
0.1
|
III
|
3, 7
|
0.3
|
IV
|
4, 8
|
0.5
|
2.
5 ml of suspension was poured
into the weighing boat and was labeled. Texture, clarity and color of the
suspension was described and compared.
3.
50 ml of suspension was poured
into 50 ml measurable cylinder. Height of the solid phase precipitated in the
cylinder was measured at the duration of 0, 5, 10, 15, 20, 25, 30, 40, 50 and
60 minutes.
Time
(min)
|
0
|
5
|
10
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
60
|
Height
(mm)
|
4.
4. The rest of the suspension (95
ml) was poured into 100 ml beaker and the viscosity of the suspension was
measured by a viscometer.
Reading
|
1
|
2
|
3
|
4
|
5
|
6
|
Viscosity
|
||||||
Mean + SD
|
||||||
5.
10 ml of suspension was poured
into centrifugator tube and the height of the solid phase was measured after
centrifugation (1000rpm, 5 minutes, and 25°C).
Height (mm)
|
|
Before centrifuged
|
|
After centrifuged
|
|
Height of ratio
|
RESULTS
Time (min)
|
Average height of
sedimentation (cm) ( X ± SD)
|
|||||||||||||
0
|
5
|
10
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
60
|
||
Amount of
tragacanth (g)
|
0.0
|
0
|
10
|
7
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
5
|
5
|
5
|
5
|
4
|
4
|
4
|
4
|
4
|
4
|
4
|
4
|
||
X
|
3.0
|
7.5
|
6.0
|
5.5
|
5.5
|
5.0
|
5.0
|
5.0
|
5.0
|
5.0
|
5.0
|
5.0
|
5.0
|
|
± SD
|
4.2
|
3.5
|
1.4
|
0.7
|
0.7
|
1.4
|
1.4
|
1.4
|
1.4
|
1.4
|
1.4
|
1.4
|
1.4
|
|
0.1
|
0
|
2
|
5
|
5
|
6
|
6
|
7
|
7
|
7
|
8
|
8
|
8
|
8
|
|
0
|
2
|
3
|
5
|
6
|
7
|
7
|
8
|
8
|
8
|
9
|
9
|
10
|
||
X
|
0.0
|
2.0
|
4.0
|
5.0
|
6.0
|
6.5
|
7.0
|
7.5
|
7.5
|
8.0
|
8.5
|
8.5
|
9.0
|
|
± SD
|
0.0
|
0.0
|
1.4
|
0.0
|
0.0
|
0.7
|
0.0
|
0.7
|
0.7
|
0.0
|
0.7
|
0.7
|
1.4
|
|
0.3
|
0
|
0.5
|
0.5
|
3
|
4
|
5
|
6
|
7
|
7
|
7
|
7.5
|
7.5
|
8
|
|
0
|
0
|
0
|
3
|
4
|
6
|
8
|
10
|
10
|
10
|
11
|
11
|
12
|
||
X
|
0.0
|
0.5
|
0.5
|
3.0
|
4.0
|
5.0
|
6.0
|
7.0
|
7.0
|
7.0
|
7.5
|
7.5
|
8.0
|
|
± SD
|
0.0
|
0.7
|
0.7
|
0.0
|
0.0
|
1.4
|
2.8
|
4.2
|
4.2
|
4.2
|
4.9
|
4.9
|
5.7
|
|
0.5
|
0
|
0
|
0
|
0
|
2
|
3
|
3
|
3
|
3
|
3
|
3
|
3
|
3
|
|
0
|
0
|
0
|
1
|
2
|
2
|
3
|
3
|
3
|
3
|
3
|
3
|
3
|
||
X
|
0.0
|
0.0
|
0.0
|
0.5
|
2.0
|
2.5
|
3.0
|
3.0
|
3.0
|
3.0
|
3.0
|
3.0
|
3.0
|
|
± SD
|
0.0
|
0.0
|
0.0
|
0.7
|
0.0
|
0.7
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
|
DISCUSSIONS
1. Compare the physical appearance of
the suspension formed and give the analysis.
Group
|
Tragacanth (g)
|
Texture
|
Clarity
|
Colour
|
| 1. |
0.0
|
Smooth
|
Two layers are form. The above layer is clear whereas the bottom
layer is cloudy
|
White
|
| 2. |
0.0
|
Diluted
|
Cloudy
|
Opaque white
|
| 3. |
0.1
|
Smooth, dilute
|
Initially, it is milky and not clear. After a time, it is cloudy
and the suspended matter is visible
|
White and transparent above the white layer
|
| 4. |
0.1
|
Smooth
|
Cloudy
|
White
|
5.
|
0.2
|
Viscous
|
Cloudy
|
White
|
6.
|
0.2
|
Smooth texture, viscous, not easy sediment
|
Cloudy
|
Milky white
|
7.
|
0.3
|
Very viscous, slightly smooth texture
|
Cloudy
|
Milky
|
8.
|
0.3
|
Smooth texture, more viscous
|
No sedimentation, cloudy
|
Milky white, one layer
|
2. Graph
of sedimentation height versus time. (Suspension Formulation) Discuss the
graph.
Time
(min)
|
0
|
5
|
10
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
60
|
Height
(mm)
|
0
|
0.5
|
0.5
|
3
|
4
|
5
|
6
|
7
|
7
|
7
|
7.5
|
7.5
|
8
|
|
However, after the Periodic
Chalk Mixture has been left to stand for a period of time, the sediment start
to form and the height of sediment increase as the time increase. This is
because the forces of interaction between the inter–particular attractive
forces are stronger than the inter-particular repulsive forces of the Tragacanth
powder on suspension. Particles in a
suspension will settle out if the suspension is allowed to stand undisturbed.
These particles can be redispersed when it is shaken and the sediment formed
does not show decreased in height. This is due to the present of suspending
agent. The addition of the tragacanth, at some critical
concentration, negates the surface charge on the suspended particles and allows
the formation of floccules or clusters as particles are held loosely together
by weak van der Waals forces. Since the particles are linked together only
loosely, they will not cake and may be easily redispersed by shaking the
suspension.
In addition, the height of sedimentation will increases with time until
a maximum sedimentation level is achieved. The maximum sedimentation level is
indicated by the constant level of height starting from 50 minutes till 60
minutes. This is due to the presence of tragacanth in
the suspension which makes suspension III to become more stable. The greater
the amount of suspending agent used, the longer the time taken for the sediment
to form. Suspending agents capable to suspend the particles in the suspension
which counteract the gravity force, thus forming a more stable suspension and
prevent caking from happens.
3. Plot a graph of height of sedimentation
against time for the formulations of suspension with different contents of
Tragacanth. Discuss
Time (min)
|
Average height of sediment (mm) (x±SD)
|
||||||||||||||
0
|
5
|
10
|
15
|
20
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
60
|
|||
volume of tragacanth (g)
|
0.0
|
3.0
±4.2
|
7.5
±3.5
|
6.0
±1.4
|
5.5
±0.7
|
5.5
±0.7
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
5.0
±1.4
|
|
0.1
|
0.0
±0.0
|
2.0
±0.0
|
4.0
±1.4
|
5.0
±0.0
|
6.0
±0.0
|
6.5
±0.7
|
7.0
±0.0
|
7.5
±0.7
|
7.5
±0.7
|
8.0
±0.0
|
8.5
±0.7
|
8.5
±0.7
|
9.0
±1.4
|
||
0.3
|
0.0
±0.0
|
0.5
±0.7
|
0.5
±0.7
|
3.0
±0.0
|
4.0
±0.0
|
5.0
±1.4
|
6.0
±2.8
|
7.0
±4.2
|
7.0
±4.2
|
7.0
±4.2
|
7.5
±4.9
|
7.5
±4.9
|
8.0
±5.7
|
||
0.5
|
0.0
±0.0
|
0.0
±0.0
|
0.0
±0.0
|
0.5
±0.7
|
2.0
±0.0
|
2.5
±0.7
|
3.0
±0.0
|
3.0
±0.0
|
3.0
±0.0
|
3.0
±0.0
|
3.0
±0.0
|
3.0
±0.0
|
3.0
±0.0
|
||
The graph above shows the relationship between the
height of sedimentation (mm) with time (min) for four different suspensions
that contain different amounts of tragacanth (0.0g, 0.1g, 0.3g, 0.5g). The height of sediment decreases as the weight of the tragacanth
increases. Suspension which has more
tragacanth is more stable because tragacanth acts as suspending agent. For
formulation with optimum amount of tragacanth, the system is stable and no slow
flocculation occurs. A good suspension is a suspension that have slow
sendimentation process after the suspension is shaken. This is to ensure all
the ingredient in suspension will disperse for a longer time to increase the
efficiency of suspension administration.
From the graph, it shows that the more
tragacanth content used, the less the sendiment formed with time for 0.1g, 0.3g
and 0.5g of tragacanth content. However, for 0.0g of tragacanth content it
shows initially highest sendiment rate which is 7.5mm and later become constant
at 5.0mm. This might be because, initially the suspension does not have any
suspending agent, and so that the suspension is not stable and it has very high
sendiment, after that, sendiment rate become constant due to the some of the
insoluble solid were dissolved in the solutions.
4.
Describe
briefly the mechanism of analysis of viscometer. Plot a graph of viscosity
versus weight of Tragacanth (g). Give explanation.
Amount of Tragacanth (g)
|
Readings
|
Viscosity (cP)
|
Viscosity (cP) (Average ± SD)
|
0.0
|
1
|
7.40
|
8.733 ± 1.124
|
2
|
9.40
|
||
3
|
7.70
|
||
4
|
9.50
|
||
5
|
8.20
|
||
6
|
10.20
|
||
0.1
|
1
|
7.00
|
6.583 ± 0.801
|
2
|
6.50
|
||
3
|
6.00
|
||
4
|
6.00
|
||
5
|
6.00
|
||
6
|
8.00
|
||
0.3
|
1
|
3.00
|
4.900 ± 1.221
|
2
|
4.70
|
||
3
|
5.90
|
||
4
|
4.00
|
||
5
|
5.90
|
||
6
|
5.90
|
||
0.5
|
1
|
13.20
|
12.967 ± 6.476
|
2
|
6.20
|
||
3
|
16.80
|
||
4
|
19.40
|
||
5
|
18.20
|
||
6
|
4.00
|
Equation:
Weight of Tragacanth (g)
|
0.0
|
0.1
|
0.3
|
0.5
|
8.733
|
6.583
|
4.900
|
12.967
|
Viscometer is a
motor of viscometer that operates by rotating with the speed of 300rpm which is
controlled by the central controller. The stirrer is rotated by disc that in
turn moved by spring more than 180°. Besides, the change of rotation degree is
directly proportional to the viscosity of the fluid and its rate of rotation.
Infra red radiations emitted by LED is then diffuse through disc before
detected by photo diod. Change in degree of disc rotation will influence the
infra red radiation and this is detected and read by photo diod.
From the graph above, Suspension IV is the most
viscous suspension compared to other suspensions formed. The more tragacanth
added, the more viscous of the suspension being formed. According to theory,
viscosity decreases from suspension IV to suspension I. The graph obtained should be linear where the viscosity of
suspension is directly proportional to the amount of tragacanth. Chalk is
suspended by tragacanth in the liquid phase and form suspension. When the
amount of tragacanth is increased, suspension that forms will be more viscous.
However, we do not obtain such graph because there are some mistakes in this
experiment. For the
value of suspension II and III in the graph, the values should be increasing
instead of decreasing. This may due to the errors occur during the
experiment. The
errors include insufficient
amount of tragacanth added to suspension. Besides that, viscometer may not be
cleaned appropriately after used. This may affects the reading of the
viscometer. Therefore, the viscosity
graph of the suspensions obtained is different from theoretical graph.
5.
Plot
a graph of height of ratio of sediment as a result of centrifugation vs. weight
of Tragacanth. Give explanation.
Amount of
Tragacanth (g)
|
Height (mm)
|
Height ratio
|
Height ratio
(Average ± SD)
|
||
Before centrifuge
|
After centrifuge
|
||||
Liquid phase
|
Solid phase
|
||||
0.0
|
85
|
70
|
15
|
4.667
|
5.834 ± 1.650
|
80
|
70
|
10
|
7.000
|
||
0.1
|
82
|
62
|
20
|
3.100
|
5.300 ± 3.111
|
85
|
75
|
10
|
7.500
|
||
0.3
|
80
|
65
|
15
|
4.333
|
3.619 ± 1.010
|
82
|
61
|
21
|
2.905
|
||
0.5
|
77
|
68
|
9
|
7.556
|
5.334 ± 3.143
|
74
|
56
|
18
|
3.111
|
||
Equation:
Theoretically,
increasing the amount of tragacanth will decrease the height ratio of sediment. It is based on function of tragacanth itself as suspending agent.
Most of suspending agents accomplish two purposes. Suspending agents form film
around particle and decrease interparticle attraction so prevent from
coalescence. Besides, suspending agents also act as thickening agents. They
increase in viscosity of the solution, which is necessary to prevent
sedimentation of the suspended particles as per Stoke’s’s law.
A good suspension should
have well developed thixotropic. At rest the solution is sufficient viscous to
prevent sedimentation and thus aggregation or caking of the particles. When
agitation is applied the viscosity is reduced and provide good flow
characteristic from the mouth of bottle. Based on the graph above, as the
amount of tragacanth volume is
increased, the height ratio is decreased until point of 0.3g of tragacanth, it
start to increase again. So basically,
this experiment is not correct because the graph show the increasing of height
ratio. This could be because of some errors during handling this
experiment. For example, make a mistake during measuring tragacanth or other
substance. Or, it could be tragacanth itself not function normally because of
interaction due to impuruities or the tragacanth is already affected during
storage.
6.
What
is the function of each material that is used in the suspension formulation?
How is the use of different amount of Tragacanth affect the physical
characteristic and stability of a suspension formulation?
The list of materials used in
this suspension preparation are chalk, tragacanth, concentrated peppermint
water, syrup BP, double-strength Chloroform Water and distilled water. Chalk
functions as the active ingredient in this suspension preparation. Chalk also
plays a role as an adsorbent that adsorbs excessive fluid in watery compound in
order to make the compound becomes more solid and drier. Tragacanth acts as a
thickening agent in the suspension preparation. Tragacanth also helps to
increase the viscosity and the stability of a suspension preparation.
Concentrated peppermint water functions as a flavouring agent that helps to
mask an unpleasant taste and improves patient’s compliance. Syrup BP plays a
role as a sweetening agent and a flavouring agent. Double-strength Chloroform
Water plays a role as a preservative, which helps the suspension preparation to
become infavourable to microbial growth. Distilled water is used as a vehicle
and a bulking agent in this suspension preparation. The usage of the different
concentration of tragacanth can influence the texture, clarity and the colour
formed in the suspension preparation. Based on the results obtained on the
texture, clarity and colour of the suspension formed, when the amount of
tragacanth used increases, the viscosity of the suspension increases. This
shows that when the viscosity of the suspension increases, the suspended
particles take a longer time to separate from the vehicle and form two layers.
Moreover, when the amount of tragacanth increases, the colour of the suspension
preparation becomes more milky white. This shows that the suspension
preparation has a higher stability with the increase of the amount of
tragacanth used.
Group 1 and 2 do not use any
tragacanth in their suspension preparation. Thus, the suspension preparation
has a diluted, smooth texture and less viscous. The suspension also forms two
layers very easily and the colour is white. This shows that there is no
suspending or also known as thickening agent, which aids in the viscosity and
the stability of the suspension formed. When the amount of tragacanth added to
the suspension preparation increases, the texture of the suspensions become
more viscous and also smooth. The suspension preparation also does not sediment
easily. This shows that the tragacanth acts as a suspending agent which
increases the viscosity and the stability of the suspension preparations. The
tragacanth also acts as a thickening agent which causes the suspension
preparation to become more milky white in colour as the amount of tragacanth
used increases.
CONCLUSION
For
the experiment, we conclude that different amount of tragacanth will give
different characteristic effect of suspension. The higher the amount of
tragacanth used, the lower the height of sedimentation. Theoretically,
increasing the amount of tragacanth used will increase the viscosity of
suspension. However from this experiment, due to some errors, the viscosity
decreased as amount of tragacanth increase, only upon 0.3g of tragacanth, the
graph showed increasing on viscosity.
REFERENCES
No comments:
Post a Comment