Compounding of Pastes
Session 8 Compounding of Pastes
Total Session Time: 120 Minutes
Prerequisites
Learning Tasks
By the end of this session students are expected to be able to:
Define paste
Describe procedures for preparing paste
Prepare paste
Label prepared paste
Dispense prepared paste into suitable containers and closure
Resources Needed:
SESSION OVERVIEW
Activity/
Step Time Content
Method
1 05 Minutes Presentation Introduction, Learning Tasks
2 10 Minutes Presentation Definition of Paste
20 Minutes Presentation Procedures for Preparing Paste
3
Buzzing
45Minutes Presentation
4 Preparing Paste
Demonstration
20 Minutes Presentation
5 Labeling of Prepared Paste
10Minutes Presentation Dispensing of Prepared Paste into Suitable Containers
6
Brainstorming and Closure
7 05 Minutes Presentation Key Points
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8 05 Minutes Presentation Evaluation
SESSION CONTENTS
STEP 1: Presentation of Session Title and Learning Tasks (5 minutes)
READ or ASK students to read the learning tasks and clarify
ASK students if they have any questions before continuing.
STEP 2: Definition of Paste (10 minutes)
finely dispersed in the basis
o Fatty pastes e.g.: Lassar's paste
o Non greasy pastes e g: Bassorin paste
o Coal tar paste P.CX (astringent, antipruritic)
o Compound zinc paste P.CX (astringent)
o Zinc and Salicylic acid Paste P.CX (Lassar‟s paste) astringent
o Contain more solids than ointments
o Are stiffer than ointments
o Are less greasy than ointments
o Cause less maceration of the skin
o Are less occlusive than ointment
This is because of high porosity caused by high powder content
o Are more absorbent to exudate weeping lesions
o Pastes are less penetrating and less macerating and less heating than ointment
o Like ointments; paste forms an unbroken relatively water – impermeable film
o Unlike ointments; film formed by pastes is opaque, thus can be used as an effective sun block
accordingly.
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STEP 3: Describe Procedures for Preparing Pastes (20 minutes)
Activity: Buzzing (10 minutes)
Ask students to brainstorm on the following question:
ALLOW few students to respond?
WRITE their responses on the flip chart/ board
CLARIFY and SUMMARISE by using the content below
o e.g. Compound Zinc Paste P.CX (Syn Zinc Paste)
o Zinc oxide, finely sifted ……………….. 25.0g
o Starch, finely sifted……………………….25.0g
o White soft paraffin……………………….50.0g
o The powders are triturated with the melted soft paraffin
STEP 4: Preparation of Pastes (45 minutes)
Activity: Demonstration (45 minutes)
DIVIDE students in small manageable groups.
PREPARE equipment and materials needed for demonstration
POSITION students so that everyone can see and hear
REVIEW steps of preparing pastes with students
REFER students to the official formula of preparing compound zinc paste PCx In the
Tanzania Pharmaceutical Handbook
DEMONSTRATE the procedure of preparing ointments according to the instruction under the
official formula in the Tanzania Pharmaceutical Handbook (Mitte 50g)
ALLOW one student from each group to do a return demonstration and let others comment on it
CLARIFY and SUMMARIZE Using the content below
INFORM the students that “every student will practice in the skills laboratory under supervision
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until is competent”
Zinc oxide, finely sifted………………………………………………………..25.0g
Starch, finely sifted……………………………………………………………..25.0g
White soft paraffin………………………………………………………………50.0g
Mitte 50.0g for Alex Shabani
Official amount
100gm
Then, amount of each ingredient can be obtain as summarised in the table below:
Formula Official amount Factor Required amount
Zinc oxide, finely 25.0gm 0.5 12.5gm
sifted
Starch, finely sifted 25.0gm 12.5gm
White soft paraffin 50.0gm 25.0gm
Method of preparation
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STEP 5: Labeling of Prepared Paste (20 minutes)
o As for ointments
Activity: Demonstration (10 minutes)
DIVIDE students in small manageable groups.
PREPARE equipment and materials needed for demonstration
POSITION students so that everyone can see and hear
REVIEW steps of writing a label
REFER students to the important things required to appear on the label.
DEMONSTRATE on how to write a good label
ALLOW one student from each group to do a return demonstration and let others comment
on it
CLARIFY and SUMMARIZE by using the content below
INFORM the students that “every student will practice in the skills laboratory under
supervision until is competent”
For External Use Only
ZINC AND SALICYLIC ACID PASTE PCx
100g
Spread paste on white lint and place on to the affected area every twenty four
hours for five days.
The name of the dispenser and the name and address of the dispensing Institution
Preparation date
Expiry date
Keep Out of Reach of Children
Keep away from heat
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STEP 6: Dispensing of Prepared pastes into Suitable Containers and
Closure. (10 Minutes)
Activity: Brainstorming (05 minutes)
Ask students to brainstorm on the following question:
ALLOW few students to respond?
WRITE their responses on the flip chart/ board
CLARIFY and SUMMARISE by using the content below
o As for ointments
o Pastes tubes of metal or plastic or in wide-mouthed jars of glass or plastic
Figure 8.1: Paste jars and tube
Source: Pharmaceutical Compounding and Dispensing (2008).
STEP 6: Key Points (5 minutes)
finely dispersed in the basis
separation (sieving) and mixing (Fusion or Trituration),
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wide-mouth glass or plastic jars with plastic screw caps with impermeable liners or close fitting
slip-on lids
STEP 8: Evaluation (5 minutes)
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References
Britain, R. P. S. o. G. (1994). The Pharmaceutical Codex (12 ed.). London: London Pharmaceutical
Press.
Winfield, J. A. R., I. Smith. (2009). Pharmaceutical Practice (4th ed.)British
Singh Malik, D; Mital, N; Kaur, G (2016). "Topical drug delivery systems: a patent
review". Expert opinion on therapeutic patents. 26 (2): 213–28. Sudan
Senya, S. S., Mwasha, C. Y. S., Muyinga, A. M., Amiri, R. I., & Mauga, E. A. S. K. (2011).
Tanzania Pharmaceutical Handbook (2nd ed.). Dar es salaam.
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