Stability of Pharmaceutical Dosage Forms
Session 9: Stability of Pharmaceutical Dosage Forms
Total Session Time: 120 minutes
Prerequisites
Learning Tasks
By the end of this session students are expected to be able to:
Forms
Dosage Forms
•
Resources Needed:
SESSION OVERVIEW
|Step |Time |Activity/ |Content |
| | |Method | |
|1 |05 minutes |Presentation |Introduction, Learning Tasks |
|2 |10 minutes |Presentation |Definition of Stability and the |
| | |Brainstorming |Effects of Instability of Dosage |
| | | |Forms |
|3 | |Presentation |Chemical, Physical and |
| |60 minutes |Small Group |Microbiological Stabilities of |
| | |Discussion |Dosage Forms |
|4 |20 minutes |Presentation |Factors Affecting Stability of |
| | |Buzzing |Pharmaceutical Dosage Forms |
|5 |15 minutes |Presentation |Effects of Packaging Materials on |
| | |Buzzing |Stability of Pharmaceutical Dosage |
| | | |Forms |
|6 |05 minutes |Presentation |Key Points |
| 7 |05 minutes |Presentation |Evaluation |
SESSION CONTENTS
STEP 1: Presentation of Session Title and Learning Tasks (05 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 Stability and The Effects of Instability (10 minutes)
|Activity: Brainstorming (5 minutes) |
| |
|Ask students to brainstorm on the following question: |
| |
|What is stability of a drug or dosage form? |
| |
|ALLOW few students to respond? |
| |
|WRITE their responses on the flip chart/ board |
| |
|CLARIFY and SUMMARISE by using the content below |
within specifications established to ensure its identity, strength
quality and purity
storage and use (shelf-life), the same properties and characteristics
that it possessed at the time of its manufacturing
o Undesired change in performance, i.e. dissolution/bioavailability
o Substantial changes in physical appearance
o Product failures
STEP 3: Chemical, Physical and Microbiological Stabilities of Dosage Forms
(60 minutes)
|Activity: Small Group Discussion ( 30 minutes) |
| |
|DIVIDE students into small manageable groups |
| |
|ASK students to discuss on the following question |
|What are the implications of physical, chemical and microbiological |
|stabilities to pharmaceutical dosage forms? |
| |
|ALLOW students to discuss for 15 minutes |
| |
|ALLOW few groups to present and the rest to add points not mentioned |
| |
|CLARIFY and SUMMARIZE by using the contents below |
o Physical stability
o Chemical stability
o Microbiological stability
o The formulation is totally unchanged throughout its shelf life and has
not suffered any changes by way of appearance, organoleptic
properties, hardness, brittleness and particle size
o It is significant as it affects:
o Examples of physical instabilities include:
o The lack of any decomposition in the chemical group that is
incorporated in the formulation as the drug, preservatives or any
other excipients
o This decomposition may influence the physical and chemical stability
of the formulation
o Decomposition occur by degradation mechanisms which are:
suitable packing in amber coloured bottles, cardboard outers and
aluminium foil over wraps
o It is significant as it affects:
o The formulation has not suffered from any microbiological attack and
is meeting the standards with respect to sterility or lack of
contamination
o The sources of microbiological contamination can be:
o Microbiological contamination occurs mostly during storage and in
order to prevent it, there must be:
o It is significant as it affects/causes:
direct to the systemic circulation)
STEP 4: Factors Affecting Stability of Pharmaceutical Dosage Forms (20
minutes)
|Activity: Buzzing (5 minutes) |
| |
|ASK students to pair up and buzz on the following question for 2 |
|minutes |
| |
|What are the factors affecting stability of the pharmaceutical dosage |
|forms? |
| |
|ALLOW few pairs to respond and let other pairs to add on points not |
|mentioned |
| |
|WRITE their response on the flip chart/board |
| |
|CLARIFY and SUMMARIZE by using the content below |
o High temperature accelerates oxidation, reduction and hydrolysis
reaction which lead to drug degradation
o Affects drug stability through its energy or thermal effect which lead
to oxidation
o Acidic and alkaline pH influences the rate of decomposition of most
drugs
o Many drugs are stable between pH 4 and 8
o Water catalyses chemical reactions such as oxidation, hydrolysis and
reduction
o Water promotes microbial growth
which affect the instability of pharmaceutical dosage forms. These
include drug nature, excipient(s) properties, particle size and
leaching of the containers
STEP 5: Effects of Packaging materials on Stability of Pharmaceutical
Dosage Forms (15 minutes)
|Activity: Buzzing (5 minutes) |
| |
|ASK students to pair up and buzz on the following question for 2 |
|minutes |
| |
|What are the effects of packaging materials on stability of |
|pharmaceutical dosage forms? |
| |
|ALLOW few pairs to respond and let other pairs to add on points not |
|mentioned |
| |
|WRITE their response on the flip chart/board |
| |
|CLARIFY and SUMMARIZE by using the content below |
affecting product stability
o Are resistant to chemical and physical change and are the most
commonly used materials
o Are not good in packaging
o Plastics affect stability through:
the pharmaceutical product
o Various alloys and aluminium may be used as containers for emulsions
and ointments
o Sometimes may cause corrosion and precipitation but this can be
avoided by coating the tubes with polymers
o Have the problems of extraction of drug ingredients and leaching of
container ingredients
o The pre-treatment of rubber vials, stoppers and closures with water
and steam reduces potential leaching
STEP 6: Key Points (05 minutes)
period of storage and use (shelf-life), the same properties and
characteristics that it possessed at the time of its manufacturing
includes light, temperature, pH-level, humidity and nature of
packaging materials
materials in order to maintain the stability of pharmaceutical dosage
forms
STEP 7: Evaluation (05 minutes)
forms?
of pharmaceutical dosage forms?
References
Aulton, M.E.,Taylor, M.K. (2001). Pharmaceutics: The Science of dosage form
design
(2nd ed.). USA: Churchill Livingstone.
Cooper, J.W., Gunns, C., & Carter, S.J. (2008). Dispensing for
Pharmaceutical Students
(12th end). Delhi, India: CBS Publishers and Distributors.
Rawlins, E.A. (2001).Bentley’s Textbook of Pharmaceutics (8th ed.). London,
UK:
Bailliere Tindall.
Thorat et al. (2014) .World Journal of Pharmacy and Pharmaceutical
Sciences: India
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