NFNF2263
PHARMACEUTICAL TECHNOLOGY 2
SEMESTER
2
SESSION
2012 / 2013
PRACTICAL REPORT 3
TITLE : EXP 3:
Evaluation of different effects of ingredients towards the ointment
formulation.
2. LIM GUCCI (A136085)
3.LIM ZEN HUEI (A136194)
4.TEH THIAN SIANG (A136169)
5. PUTERI EFFY NASTASHEA BINTI HOSLAM (A136042)
LETURER : DR HALIZA BINTI KATAS
FACULTY OF PHARMACY
UNIVERSITI KEBANGSAAN MALAYSIA
Title:
Evaluation of
different effects of ingredients towards the ointment formulation.
Objective:
To study the effect of ointment composition towards the
physical properties of the ointment and the rate of drugs release from the
ointment formulation.
Introduction:
Ointment formulation is a suitable
semisolid dosage form for the application on the skin. It is an oily preparation
that contains one or more of the dissolved active drug or distributed
homogenously. A good ointment should have attractive texture, easily applied
onto the skin and release the active drug readily.
Usually, ointment consists of active
ingredients (powder or liquid) which are incorporated into the oily semisolid
carrier. In the pharmaceutical industry, the ointment preparation is used for
topical treatment at the application site and to increase the moistures of the
skin (emollient effects).
Apparatus: Ingredients:
Weighing instrument Emulsifying
wax
Weighing boat White
soft paraffin
100ml beaker Liquid paraffin
Heater Acetylsalicylic
acid
1 set of cream and spatula Distilled
water
Mortar and pestle
Dialysis bag (10cm)
Thread
Glass rod
Water-bath
1 set of pipette (5 ml) and
pipette-bulb
1 plastic kuvet
Procedure:
1.
50g of Emulsifying Ointment was prepared for the
following formulation:
Emulsifying Ointment
|
Ingredients (g)
|
Total (g)
|
||
Emulsifying wax
|
White soft paraffin
|
Liquid paraffin
|
||
I
|
21
|
25
|
4
|
50
|
II
|
17
|
25
|
8
|
50
|
III
|
13
|
25
|
12
|
50
|
IV
|
9
|
25
|
16
|
50
|
- 5 g of cream was taken and put into the weighing boat
and was labeled. The texture, clarity and the color of the cream was
described and compared.
- 1.5 g of Acetylsalicylic acid powder was incorporated
into 30 g of cream which was prepared by levigation technique.
- Acetylsalicylic acid was filled into the dialysis bag
and the two side of the bag was tied.
- The bag was put into a beaker (200ml) filled with
distilled water (100ml) which was heated to 37°C.
- Every 5 minutes, one aliquot sample (3 – 4 ml) was
pipette and the release of Acetylsalicylic acid from the cream base was
determined by using spectrometer UV-visible. The distilled water was
stirred with glass rod before the sample was taken.
Results :
Time(min)
|
UV absorption at 310 nm
|
0
|
0
|
5
|
0.036
|
10
|
0.040
|
15
|
0.065
|
20
|
0.082
|
25
|
0.109
|
30
|
0.122
|
35
|
0.141
|
40
|
0.177
|
45
|
0.180
|
50
|
0.225
|
55
|
0.246
|
60
|
0.250
|
Discussions:
1. Compare the physical characteristics of the
ointments and explain.
Group
|
Material (g)
|
Texture of ointment
|
Clarity
|
Colour
|
|||||
Emulsifying
wax
|
White
soft paraffin
|
Liquid
paraffin
|
Spreadibility
|
Greasiness
|
Hardness
|
||||
5
|
21
|
25
|
4
|
Most
difficult
|
Least
greasy
|
Hardest
|
Turbid
|
White
|
|
6
|
17
|
25
|
8
|
Difficult
|
Relatively
greasy
|
Hard
|
Turbid
|
White
|
|
7
|
13
|
25
|
12
|
Intermediate
|
Greasy
|
Soft
|
Turbid
|
White
|
|
8
|
9
|
25
|
16
|
Easy
|
Most
greasy
|
Softest
|
Turbid
|
White
|
|
The ointments that are formulated by each group are the same
in the composition of white soft paraffin however the composition of the
emulsifying wax and the liquid paraffin are different for each group. The
quantities for both of these materials are varied to make up a total amount of
50g of ointment. All the ointment that is formulated is white in colour and
turbid. The degree of the turbidity of the ointment depends on the amount of
emulsifying wax added to the formulation. As the amount of the emulsifying wax
increased in the formulation it will be easier for the ointment to spread upon
application. The greasiness of the formulation also increases as the amount of
emulsifying wax increases in the formulation. The quantity emulsifying wax in
the formulation will also cause the hardness of the ointment to vary. The lower
the quantity of emulsifying wax, the softer the ointment produced.
- Plot a graph of UV absorption versus time. Give reason.
In this experiment , the dialysis bag is resembled
to the phospholipid bilayer of the cell membrane of human where the absorption
occurs across the membrane into the distilled water which is resembled to the
blood plasma. The temperature of distilled water is maintained at 37ºC which is
the temperature of human body.
The amount of drug absorbed into the blood
circulation is represented by the concentrations of the drug in the distilled
water. The UV absorption represents the concentration of the drug that crosses
the membrane and reaches into the
distilled water.
In theory, the UV absorption is proportional to
the time of the release of salicyclic acid across the membrane to distilled
water. The gradient of the graph shows the rate of drug release across the
membrane of dialysis bag.
The graph shows that as the time increases, the
concentration of the salicyclic acid in the distilled water is increasing.
Along the time until a particular point, the gradient of the graph decreases
thus the releasing rate is reduced. Along the progression of the experiment,
the concentration of salicyclic acid in the dialysis bag and the distilled
water become isotonic because the salicyclic acid keeps moving into the
distilled water. The gradient of graph decreases because the salicyclic acid
diffuses into and out of the membrane of dialysis bag in an equilibrium state.
At the late stage, the releasing rate increases. This may be contributed by the
experimental error such as leakage of the drug whereby the thread is not tight
tightly enough or the distilled water is
stirred too vigorously.
3.
Plot graph UV absorption against time for the
ointment formulation with different composition. Compare and discuss the
results.
From the graph above, the formulation 1 has the
highest concentration of acetylsalicylic acid in the distilled water.
Theoretically, low concentration of acetylsalicylic acid in the distilled water
should be shown. Physically, formulation 1 ointment is harder than the other
ointments. Formulation 1 should show slow release rate due to the high
proportion of the emulsifying wax and low proportion of liquid paraffin.
Usually hydrophilic acetylsalicylic acid can disperse uniformly in the
ointment, due to high proportion of the emulsifying agents (emulsifying wax).
However, the oil phase (liquid paraffin and soft paraffin) is not enough for
the acetylsalicylic acid to diffuse through the membrane. Hence concentration
of acetylsalicylic in the distilled water should be low.
From
the book Differential diagnosis in dermatology written by Richard Ashton,
Barbara Leppard, the ideal formulation of ointment has the percentage of
emulsifying wax, white soft paraffin and liquid paraffin at 30%, 50%, 20%
respectively.
The
graph shown indicates that formulation 2 has higher concentration of
acetylsalicylic acid in distilled water than formulation 3. Theoretically, as
the amount of emulsifying wax decrease and amount of liquid paraffin increases,
the acetylsalicylic acid can diffuse through the membrane better which means
that isotonicity can be achieved between ointment and the surrounding distilled
water in a faster way. In formulation 2, the percentage of emulsifying wax,
white soft paraffin and liquid paraffin should be 34%, 50%, 16% respectively.
Meanwhile, in formulation 3, the percentage of emulsifying wax, white soft
paraffin and liquid paraffin should be 26%, 50%, 24% respectively. Both
formulations shows only 4% difference with the ideal formulation. Thus, these
formulations encourage the diffusion of drugs into the distilled water through
the membrane.
Formulation
4 has the lowest concentration of acetylsalicylic acid in distilled water.
Although there is a high amount of liquid paraffin to assist in the diffusion
of acetylsalicylic acid, but insufficient emulsifying wax causes
acetylsalicylic acid unable to disperse properly in ointment. Therefore,
acetylsalicylic acid has low concentration in distilled water.
As
the time goes on, the concentration of acetylsalicylic acid in distilled water
gradually increases for every formulation. However, in formulation 2 there is a
slight decrease in concentration during 30 minutes to 35 minutes. This is due
to uneven stirring or absence of stirring before taking out the volume, the
concentration of acetylsalicylic acid is unevenly distributed in the distilled
water. Hence, the volume taken out maybe less concentrate than the previous
concentration.
4. What is the function of each ingredient
using in the preparation of ointment. How the usage of different content of
Emulsifying Wax and Liquid Paraffin influence physical characteristic of the
ointment formulation and its drug releasing rate?
Emulsifying Wax
|
Substance added to an emulsion to prevent the coalescence
of the globules of the dispersed phase. They are also known as emulgents or
emulsifiers. They act by reducing the interfacial
tension between the two phases and forming a stable interfacial film.
It can increase the water solubility of the ointment.
|
White Soft Paraffin
|
It is reserved for products with colourless, white or pale
ingredients. It inhibits water loss from the skin by forming a greasy layer,
and this in turns improves the hydration of the skin in dry scaly conditions.
|
Liquid Paraffin
|
Liquid paraffin increases the lipophilicity of ointment, so
that it can penetrate the membrane. It also used to reduce the viscosity of
the ointment.
|
Acetylesalicylic acid
|
An active ingredient used as an analgesic to relieve minor
aches and pains, as an antipyretic to reduce fever, and as an
anti-inflammatory medication.
|
Liquid paraffin
increases the liphophilicity of ointment, so that it can penetrate the
membrane. Emulsifying wax increase the water solubility. The higher the amount
of emulsifying wax, the greater the capability of the ointment to hold water.
The greater the amount of the liquid paraffin, the higher the lipophilicity,
the greater the penetration of the drugs .
Conclusion:
Physical properties of the ointment
and the rate of release of drug from the formulation can be influence by
different composition of the ointment. Thus, the components of the formulation
must be in suitable proportion to produce a drug which has desired therapeutic
effect.
References:
1.
Aulton, M.E. 2002. Pharmaceutics: The science of
dosage form design. Edinburgh: Churchill Livingstone
2.
Florence,A.T. & Attwood, D. 1998. Physico-chemical
principles of pharmacy. 3rd Ed. New York: Macmillan.