Date : 26th MARCH 2014
Title of experiment:
The effects of differences characteristic of active ingredient in formulation of suspension.
Objectives:
1) To study the effects of difference amount of tragacanth used in the formulation of suspension.
2) To describe and elaborate the texture, clarity and colour of suspension formed.
3) To determine the viscosity and the ratio of height’s precipitate formed using different amount of tragacanth.
Introduction
A suspension is a two phased system in which a finely divided solid is dispersed in a continuous phase of solid, liquid, or gas. The undissolved solid exists in equilibrium with a saturated solution of the solid in the continuous phase. A pharmaceutical suspension is a coarse dispersion in which insoluble solid particles are dispersed in a liquid medium. Normally, they are visible under a microscope, and some can be seen with the naked eye. Particles in a suspension precipitate if the suspension is allowed to stand undisturbed. Generally, suspension comprised of active ingredient/s, wetting agent, flavouring, colouring as well as preservatives. The function of wetting agent such as tragacanth that we are used in this experiment is to reduce the surface tension between liquid and solid particles.
Apparatus
1 weighing boat, 1 set mortar and pestle, 1 plastic bottle 150 ml, 1 measuring cylinder 50 ml, 1 measuring cylinder 200 ml, 1 set pipette 1ml, 1 beaker 100 ml, viscometer tool, homogenization tool
Material
Chalk, tragacanth, concentrated peppermint water, syrup BP, double-strength chloroform water, distilled water.
Procedure
1) A formulation of Pediatric Chalk Mixture suspension (150ml) were prepared by using this formula:
2) 5 ml of suspension that are formed was poured into the weighing boat and the texture, clarity and colour of the suspension that is formed was examined.
3) 50 ml of suspension that are formed was poured into 50 ml measuring cylinder, and the height of precipitate formed in the measuring cylinder was measured at every 5 minutes ( 0 minute to 60 minutes).
4) The remaining volume of the suspension that are formed( 95 ml) was poured into the 100 ml beaker and the viscosity of the suspension was determined by using viscometer tool.
5) 10 ml of suspension that are formed was poured into the homogenize tube and the height of solid phase formed in the tube after homogenization was determined ( 1000 rpm, 5 minutes,25 ° C)
result
Discussion
Compare the physical appearance of the suspensions that formed.
The texture of the solution become more concentrated which directly proportional to the amount of tragacanth that had been added. The clarity of the solution is clear when amount tragavanth is zero. This is due to the absence of suspending agent and the chalk sendiment in high sendimentation. Compare to others, their clarity is decrease as the amount of tragacanth increase. The higher amount tragacanth cause the suspension look highly opaque due to low sedimentation rate of suspensoid as well as the colour of suspension, it become white when higher amount of suspending agent is present in the solution. The use of suspending agents causing disperse element become suspense in long duration and homogenous white colour can be directly observed.
Plot a graph of height of sediment vs. time. Give explanation.
The graph above is the formation of sediment for formulation I. Sediment starts once the time started to count.when time is increase, the height of the sendimentation decrease. This is because the sediment arrange themselves to each other cause forming a more compact sendiment.Sedimentation occurs due to the gravitational forces in which comparatively large drug particles will be sedimented. The height of the sediment becomes constant when all the chalk particles are sedimented.
plot a graph of height sediment against difference amount of tragacanth used
plot a graph of height sediment against difference amount of tragacanth used
For suspension 1 which is the one that without tragacanth, there is a sharp increase in the height of sedimentation from 0 to 100 mm from 0 to 5 minutes. After 5th minutes, the height of sedimentation had been decreased gradually until it reached the height where equilibrium is reached. The sharp increase in the height of sedimentation is due to the particles that tend to regroup and flocculate. Therefore, the dispersed phase settles to the bottom quickly. For suspension 2 (with 0.1g of tragacanth), there is an increase of height from time to time. For suspension 3, which contain 0.3g of tragacanth, the height of the sediment increases. This is due to the presence of greater amount of tragacanth in the suspension which makes suspension 3 becomes more stable than suspension 2. The greater the amount of suspending agent used, the longer the time taken for the sediment to form since the suspension is more stable. For suspension 4, which contains 0.5g tragacanth, the height of the sediment increases dramatically. The height of the sediment is then remains constant from 20 to 60 minutes. With a high amount of tragacanth, the particles remain suspend in the suspension which counteract the gravity force, thus there is no caking of suspension. It is readily to be redispersed and it can be considered as a stable suspension. Tragacanth acts as suspending agent that increases the viscosity of the suspension. The lesser the tragacanth content, the faster the insoluble particles settle at the bottom of measuring cylinder.
Plot a graph of viscosity against amount of tragacanth
Based on the graph, at first the viscosity of the suspension firstly dropped when as the amount of tragacanth increased from 0.0g to 0.3g. The viscosity of suspension will increase when the amount of tragacanth is 0.5g. As the amount of tragacanth increase, the viscosity of the suspension will also increase. Tragacanth act as a common gelling agent and a is a high molecular weight polymer. It will be hydrated when water is added to it due to the presence of galacturonic acid. The attraction of R-COO group with water causes long and short distance order, leading to overall thickening effect. This effect will increase when more tragacanth is added as the more tragacanth molecule will interact with water, leading to increase in thickness of the suspension. The graph is different from stated in the fact could be due to error occurred while handling the equipment or materials during the experiment.
A viscometer contains a spindle which will turn in a suspension fluid at a known speed. The viscometer will measures the torque required to turn a spindle in a suspension fluid at a known speed. The torque required to turn the spindle is quantified as the shear stress acting across the surface area of the spindle. The fixed speed of the viscometer would be the shear rate. The higher the shear stress the higher the viscosity of the suspension. The viscometer is measured in the unit of centipoise (cP)
Plot a graph of height ratio of the precipitation caused by centrifuge against content of tragacanth. Give comment.
From the graph, overall it show that when the content of tragacanth increases, the height ratio increase. This is similar to the theory. This is because when content of tragacanth which act as suspending agent increases, the suspension is suspended better, thus the sedimentation volume will increase which cause the height ratio to be higher. In contrast, in suspension with low concentration of tragacanth, the solid is not suspend well, thus they tend to sediment in closely manner and producer a lower sedimentation volume.
However, during the experiment, when 0.5 g of tragacanth was used, the height ratio decreases. This may due to errors that were made during the experiment. First, before the sample was being placed into the centrifuge, less than 10ml of the sample was taken. This cause the mixing to be uneven which may cause inaccurate result. Besides, when height ratio is measured, the results were taken approximately as the sediment is cloudy and white in colour. The measurement may be varied between different subjects
What is the function for each ingredients used in the suspension preparation? How does the different amount of tragacanth usage affects the physical property and stability of a suspension formulation?
In the formulation, the chalk act as an active ingredient. Tragacanth act as suspending agent and also act as thickening agents. Concentrated cinnamon water act as flavoring agent for the suspension. Double strength chloroform water act as simple preservative in oral dosage form. Distilled water act as solvent.
The higher the amount of tragacanth, the more viscous the suspension. They increase the viscosity of the solution to reduce the sedimentation rate of the suspended particles as per Stoke’s law. Tragacanth is an large size polyelectrolyte. They will adsorb onto the surface of particle, and hinder the particles to be close to each causing aggregation of particles via steric stabilization mechanism as well as charge repulsion from the galacturonic acid residue of the tragacanth molecule. Too much tragacanth would cause the suspension to be too thick which will hardened the suspension to be poured out from the container.
A viscometer contains a spindle which will turn in a suspension fluid at a known speed. The viscometer will measures the torque required to turn a spindle in a suspension fluid at a known speed. The torque required to turn the spindle is quantified as the shear stress acting across the surface area of the spindle. The fixed speed of the viscometer would be the shear rate. The higher the shear stress the higher the viscosity of the suspension. The viscometer is measured in the unit of centipoise (cP)
Plot a graph of height ratio of the precipitation caused by centrifuge against content of tragacanth. Give comment.
From the graph, overall it show that when the content of tragacanth increases, the height ratio increase. This is similar to the theory. This is because when content of tragacanth which act as suspending agent increases, the suspension is suspended better, thus the sedimentation volume will increase which cause the height ratio to be higher. In contrast, in suspension with low concentration of tragacanth, the solid is not suspend well, thus they tend to sediment in closely manner and producer a lower sedimentation volume.
However, during the experiment, when 0.5 g of tragacanth was used, the height ratio decreases. This may due to errors that were made during the experiment. First, before the sample was being placed into the centrifuge, less than 10ml of the sample was taken. This cause the mixing to be uneven which may cause inaccurate result. Besides, when height ratio is measured, the results were taken approximately as the sediment is cloudy and white in colour. The measurement may be varied between different subjects
What is the function for each ingredients used in the suspension preparation? How does the different amount of tragacanth usage affects the physical property and stability of a suspension formulation?
In the formulation, the chalk act as an active ingredient. Tragacanth act as suspending agent and also act as thickening agents. Concentrated cinnamon water act as flavoring agent for the suspension. Double strength chloroform water act as simple preservative in oral dosage form. Distilled water act as solvent.
The higher the amount of tragacanth, the more viscous the suspension. They increase the viscosity of the solution to reduce the sedimentation rate of the suspended particles as per Stoke’s law. Tragacanth is an large size polyelectrolyte. They will adsorb onto the surface of particle, and hinder the particles to be close to each causing aggregation of particles via steric stabilization mechanism as well as charge repulsion from the galacturonic acid residue of the tragacanth molecule. Too much tragacanth would cause the suspension to be too thick which will hardened the suspension to be poured out from the container.
Conclusion
The texture of the solution become more concentrated which directly proportional to the amount of tragacanth that had been added. The clarity is decrease as the amount of tragacanth increase.
The texture of the solution become more concentrated which directly proportional to the amount of tragacanth that had been added. The clarity is decrease as the amount of tragacanth increase.
As the amount of tragacanth increase, the viscosity of the suspension will also increase. When the content of tragacanth increases, the height ratio of sediment will also increase.
Reference
1. NPCS Board of Consultants & Engineers, Handbook on Textile Auxiliaries, Dyes and Dye Intermediates Technology, Asia Pacific Business Press, Delhi
2. John F. Mariott, Keith A Wilson, Christopher A Langley, Dawn Belcher, Pharmaceutical Compounding and Dispensing, Pharmaceutical Press (2006), London
3. Yokoyama, A., Srinivasan, K. R., Fogler, H. S. (1988/11)."Stabilization mechanism of colloidal suspensions by gum tragacanth: The influence of pH on stability." Journal of Colloid and Interface Science 126(1): 141-149. http://hdl.handle.net/2027.42/27076
4. A. Nussinovitch, Hydrocolloid Applications: Gum Technology in the Food and Other Industries, Blackie Academic and Professional (1997), London
2. John F. Mariott, Keith A Wilson, Christopher A Langley, Dawn Belcher, Pharmaceutical Compounding and Dispensing, Pharmaceutical Press (2006), London
3. Yokoyama, A., Srinivasan, K. R., Fogler, H. S. (1988/11)."Stabilization mechanism of colloidal suspensions by gum tragacanth: The influence of pH on stability." Journal of Colloid and Interface Science 126(1): 141-149. http://hdl.handle.net/2027.42/27076
4. A. Nussinovitch, Hydrocolloid Applications: Gum Technology in the Food and Other Industries, Blackie Academic and Professional (1997), London
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