Sunday, 12 May 2013

Experiment 4 Suppository



FACULTY PHARMACY

PHARMACEUTICAL TECHNOLOGY II
(NFNF 2263)

SEMESTER 2
SESSION 2012/2013

LAB REPORT 4
SUPPOSITORY


NAME                :
LIM ANNE YEE (A131494)
LIM GUCCI (A136085)
LIM ZEN HUEI (A136194)
THE THIAN SIANG (A136169)
PUTERI EFFY NASTASHEA BINTI HOSLAM (A136042)
 
LECTURER      : DR. NG SHIOW FERN

DATE                 : 6th MAY 2013


EXPERIMENT 4
Title
Impact Assessment of Different Ingredients on the Characteristics of a Suppository Formulation

Objective
To study the effect of using different base composition on the physical characteristics of a suppository formulation

Introduction
Suppository is a solid formulation with various sizes and shape which is suitable for rectal administration. A good suppository must melt down after administration into the rectal and release the drug for localized or systemic effect.
The drug needs to be dispersed in a suitable suppository base. A good base should not be toxic, does not produce irritation, does not react with the drug, and easy to form into a suppository. Different base composition will affect the rate and release limit of a drug from suppository.
In this experiment, the effect of different base composition on the physical characteristics of the formed suppositories and its effect on the release of the drug from it are studied.

Procedure
1.      The paracetamol powder (1g) is weighted and prepared.
2.      Paracetamol suppository (10g) is prepared using the following formula:

Suppository
Group
Material
Solution of saturated stock Paracetamol (mL)
Total
(g)
PEG 1000
PEG 6000
1
1,5
9
0
1
10
2
2,6
6
3
1
10
3
3,7
3
6
1
10
4
4,8
0
9
1
10

3.      The suppository is prepared by using suppository-mould.  Explain and compare the shape, texture, and color of the suppository.
4.      One suppository is inserted into the beaker which contains distilled water (10ml, 37 celcius ) and the time taken required to melt it down is determined.
5.      One suppository is inserted into the dialysis bag and it is ensured that both ends of the bed are tightly tied.  Then, the bag is inserted into the beaker (100ml) which contains distilled water (50ml) which is preheated to 37 celcius.
6.      At 5 minutes interval, one aliquot sample (3-4ml) is pipette and the release of Paracetamol from the suppository is determined by using UV-visible spectrometer. It is ensured that the distilled water is stirred with glass rod before taking the sample.

Results and Discussion
1)      Compare the physical characteristics of suppositories that formulated and give comment.

Suppository
Group
Material (g)
Shape
Greasiness
Hardness
Colour
PEG 1000
PEG 6000
I
5
9
0
Bullet-shaped
Very greasy
Soft
White
II
6
6
3
Bullet-shaped
Greasy
Slightly hard
White
III
7
3
6
Bullet-shaped
Slightly greasy
Hard
White
IV
8
0
9
Bullet-shaped
Least greasy
Very hard
Transparent

Based on the experiment, all the suppositories have the shape of a bullet since the mould that is being used is of this shape. The quantities of PEG 1000 and PEG 6000 different for each group and this will lead to formation of suppositories with different physical characteristics.
For the formulation that has the highest amount of PEG 1000, which means that it has the lowest quantity of PEG 6000 shows the greasiest surface compared to the other suppositories. As for the formulation with lowest amount of PEG 1000 and highest in the amount of PEG 6000, the suppository formed is the hardest of all. The former suppository provide ease to be administered to the patient compared to the latter one and the latter one may lead to pain in the process of administering.
In other words, the higher the quantity of PEG 6000 in a formulation, the less greasy the suppository will be. As for hardness, we can conclude that the higher quantity of PEG 1000 (lower quantity of PEG 6000), will produce softer suppository. As for the colour of suppositories, since the active ingredient that we used is paracetamol which is white in colour, the colour of the suppositories produce will be white but differ in the transparency degree. The formulation with the lowest amount of PEG 1000 is more transparent compared to the others.

2)      Plot a graph of time needed to melt the suppository against the quantity of PEG 6000 in the formulation. Compare and discuss the result.
Amount of PEG 6000 (g)
0
3
6
9
Group
1
5
2
6
3
7
4
8
Time taken to melt (min)
55
37
30
56
36
30
55
55
Average time (min)
46
43
33
55

PEG 6000 or also known as Polyethylene Glycol 6000 has high molecular weight of ethylene oxide and it is a water-soluble chemical. The amount of PEG 6000 will influence the release in vivo of the drug in the body because of owing to the solubilizing character of this base and due to low dielectric constant drugs may tend to remain in the base and release of acetylsalicylic acid may be slow. Therefore, we can say that the increasing amount of PEG 6000 will slow down the release of acetylsalicylic acid. Hence, the graph above shows that the highest amount of PEG 6000 (9g) need longest time (55mins) to melt the suppository. However, for the absence of PEG 6000, the time needed to melt the suppository is longer than the suppository that have immediate amount (3g and 6g) of PEG 6000. This may be due to the influence of the high amount of PEG1000 inside the suppository. Besides, there are some errors occurring during the experiment for example during the making of suppository and also during the process of drug release whereby the water bath temperature is not constant. 

3)       Plot the graph of UV absorption against time (Procedure 6). Give your comments.

    UV absorption at 520nm for Group 8 (Suppository IV)
Time (min)

UV-visible absorption at 520nm
0
5
10
15
20
25
30
35
40
45
50
55
60
UV absorption at 520nm


0


0.013


0.015


0.024


0.031


0.037


0.042


0.042


0.050


0.057


0.066


0.069


0.069

    UV absorption at 520nm for Group 4 (Suppository IV)
Time (min)

UV-visible absorption at 520nm
0
5
10
15
20
25
30
35
40
45
50
55
60
UV absorption at 520nm


0


0.013


0.015


0.024


0.031


0.037


0.042


0.042


0.050


0.057


0.066


0.069


0.069

Time (min)

Mean UV-visible absorption at 520nm
0
5
10
15
20
25
30
35
40
45
50
55
60
UV absorption at 520nm
0.000
0.0000
0.0175
0.00636
0.0205
0.00778
0.0255
0.00212
0.0300
0.00141
0.0340
0.00424
0.0365
0.00778
0.0375
0.00636
0.0440
0.00849
0.0510
0.00849
0.0590
0.00990
0.0625
0.00919
0.0655
0.00495

According to the graph plotted based on our result, the release rate of paracetamol is not so proportional to the time. Theoretically, the graph should be in sigmoid shape which indicates constant drug release rate until equilibrium is achieved. However, the graph still showing gradually increase which indicates that the drug is releasing slowly for PEG 6000 formulation.
At the first 5minutes, amount of paracetamol released into water in beaker shoots up. This is because there is a great difference in concentration gradient between water in beaker and suppository in dialysis bag. Therefore, paracetamol diffuses out quickly.
This graph deviates from the theory may be because of errors that occurred when we conduct the experiment. Firstly, uneven heating of water bath which will lead to inconstant drug release rate from the suppository. Besides that, the suppository we made may not be homogenously formed. This may cause the brittleness of PEG suppository or trapped air space in the suppository thus reducing the size and altering the drug release rate of drug from suppository dosage form. In addition to that, distilled water in which the dialysis bag is exposed to may not be stirred evenly before it is taken to be tested on spectrophotometer UV/Vis.
In this experiment, paracetamol needs to pass through the dialysis bag before it can reach distilled water. Dialysis bag represents human biological membrane while the distilled water represents human blood plasma. The melting process,drug release and drug absorption processes occur in water bath at 37ºC, which represents human body temperature.

1)        Plot a graph of UV absorption vs. time for other suppositories that have different formulation. Compare and discuss the results.
From the graph above, the results obtained from the experiment are not very accurate. Although suppository I, III and IV are gradually increased, suppository II graph is fluctuating maybe due to experimental errors described below. Theoretically, all the graphs should be in sigmoid shape. Suppository may initially dissolve slowly and paracetamol diffuse from the dialysis bag into water in beaker. Thus, the paracetamol concentration in water will be increased by time until all paracetamol are released and become saturated in water, then the paracetamol concentration will be constant.
From the Journal of Applied Pharmaceutical Science, it is stated that “When PEG-6000 was used as a channeling agent in this formulation drug release was increased accordingly but higher concentration of PEG-6000 results in decreasing release rate of drug because of increasing viscosity of the matrix channels”. Therefore, in the experiment, suppository I which does not contain PEG 6000 will give a lower paracetamol release rate compared to other suppositories because presence of PEG 1000 also allow paracetamol delivery of the suppository into the rectum.
Suppository II contains PEG-6000 that can be used as a drug delivery agent to increase drug release so it has higher paracetamol release rate compared to suppository I. The appropriate percentage for PEG suppository is 40% PEG 1000 and 60% PEG 6000. Suppository III shows the most ideal combination whereby percentage of PEG 1000 is 33.3% and that of PEG 6000 is 66.7%. So, suppository III should have the highest paracetamol release rate. However, according to the graph from the experiment, suppository II graph is slightly higher than suppository III graph. This may due to the technique and experimental error during experiment as the suppository II graph is not a sigmoid shape.
Lastly, suppository IV which contains the highest amount of PEG 6000 will give the lowest paracetamol release rate. This is due to the higher amount of hydrogen bonds formed between the PEG base molecules and the paracetamol molecules. This causes the paracetamol to be held stronger in the suppository formulation, resulting in a lower releasing rate.
Fluctuations and inaccuracy of the results are obtained from the experiment. This is because some errors may have occurred in the experiment especially during compounding of suppositories. Paracetamol powder may be not distributed evenly in the suppository formed. This can lead to uneven release of paracetamol from the formulation. Uneven stirring process before the content of the mixture is pipetted also can contribute to the inaccuracy of the results. Besides, the impurity present in the suppositories prepared also can contribute to inaccuracy of the results.

1)      What are the functions of each of the chemicals used in the preparation of suppository? How was the used of different composition of PEG1000 and PEG6000 affected the physical characteristics of the suppository and the drug release rate from the suppository?
Paracetamol used in the preparation of suppository acts as an active ingredient of the medication. It is an anti-pyretic agent, and it is also known as a pain-killer. It is commonly used for the relief of headache and minor pain. It also gives weak anti-inflammatory activity.
While the Polyethylene glycol used acts as water soluble suppository base, which enable the suppository to dissolve in rectal solution, and release the medication easily. 
Combining PEG of different molecular weights in different ratio provides some control over the consistency, the drug release rate as well as the solidity/hardness of the suppository. Increasing in the amount of PEG6000 over PEG1000 make the suppository becomes harder, but decrease the drug release rate. This is because the release rate depends on the hydrophilicity of the suppository base, as it facilitates penetration of the dissolution medium into the base with subsequent wetting and desorption of the embedded drug. The lower the molecular weight of the PEG, the higher the hydrophilicity, as it has higher hydroxyl value as compared to higher molecular weight PEG. In other word, increase amount of PEG1000 enable the suppository to release the drug more rapidly.

Conclusion
Different percentage of combination of PEG 1000 and PEG 6000 affects the physical characteristics of the suppository and the rate of release of the active ingredient.

Reference
1.      Rita Bhatta and Mohammad Salim Hossain, 2011. Evaluation of Kollidon SR based Ketorolac Tromethamine Loaded Transdermal Film. Journal of Applied Pharmaceutical Science 01 (08); 2011: 123-127. http://japsonline.com/vol-1_issue-8/23.pdf
2.      onlinelibrary.wiley.com/doi/10.1002/jps.2600640706/pdf






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