It is the capacity of a drug product to remain with in specifications established to ensure its identity, strength, quality and purity.

1. Assignment oN
Drug Stability
Course Title: Pharmacology-I
Course code: BPH-224
Submitted to
Dr.Md.Sarowar Hossain
Assistant Professor
Department of Pharmacy
Daffodil International University
Submitted by
Shopnil Akash
ID: 181-29-059
Shopnil29-059@diu.edu.bd
Section: 19th PC-A
Department of Pharmacy
Daffodil International University
Submission Date : 28 . 10. 2019

2. Table of Contents
Definition:....................................................................................................................................... 1
Factor affecting drug stability:........................................................................................................ 1
Three stabilities of drug must be considered: ................................................................................. 2
Sources of Microbial Contamination:............................................................................................. 2
Adverse effects of drug instability:................................................................................................. 3
Objective of drug stability: ............................................................................................................. 3
Reference: ....................................................................................................................................... 4

3. Drug Stability
Definition
It is the capacity of a drug product to remain with in specifications established to ensure its identity,
strength, quality and purity.
It is measured by the rate of changes that take place in the pharmaceutical dosage forms.
Factor affecting drug stability
1. Temperature: high temperature accelerate oxidation, reduction and hydrolysis reaction which
lead to drug degradation.
2. PH:
▪ Acidic and alkaline pH influence the rate decomposition of most drugs.
▪ Many drugs are stable between pH 4 and 8.
3. Moisture:
▪ Water catalysis chemical reactions as oxidation, hydrolysis and reduction reaction.
▪ Water promotes microbial growth
4. Light: affects drug stability through its energy or thermal effect which lead to oxidation.
5. Pharmaceuticals dosage forms: solid dosage are more stable than liquid dosage forms for
presence of water.
6. Concentration: rate of drug degradation is constant for the solution of the same drug with
different concentration. So, ratio of degraded part to total amount of drug in diluted solution is
bigger than concentrated solution.
7.Stock solution: are concentrated solution which diluted by using (i.e. syrup 85%) at high
concentration the stability is high
8. Drug incompatibility: reaction between components of pharmaceuticals dosage forms itself or
between this component and cover of the container.
9. Oxygen: exposure of drug formulations to oxygen affects their stability.

4. Three stabilities of drug must be considered
1. Physical stability
2. Chemical stability
3. Microbiological stability
A. Physical stability
 Crystal formation in pharmaceutical preparation
 Loss of volatile substances from pharmaceutical dosage forms
 Loss of water
 Absorption of water
 Change in crystalline form
B. Chemical stability
 It is discussed in chemical incompatibility unit
C. Microbiological stability
 Contamination from microorganisms is a big problem for all formulations
containing moisture but it can be a bother in solid dosage forms also if some natural
polymers are used because many natural polymers are fertile sources of
microorganisms.
Sources ofMicrobialContamination
 Water
 Air
 Raw materials, containers and closures
 Personnel
 Instruments and apparatus
Sources of microbial contaminations
 Water Low demand gram-negative groups: Pseudomonas,
Xanthamonas, Flavobacterium, Achromobacter
 Air Mould spores: Penicillium, Mucor, and Aspergillus
Bacterial spores: Bacillus spp. Yeasts
 Raw Materials Micrococci
 Earths Anaerobic spore formers: Clostridium spp
 Pigments Salmonella

5.  Starches Coliforms
 Gums Actinomyces
 Animal products Salmonella, Coliforms
 Personnel Coliforms, Staphylococci, Sterptococci,
Adverse effects of drug instability
 Loss of active drug (e.g. aspirin hydrolysis, oxidation of adrenaline).
 Loss of vehicles (e.g. evaporation of water from o/w creams, evaporation of alcohol from
alcoholic mixtures).
 Loss of content uniformity (e.g. creaming of emulsion, impaction of suspension)
 Loss of elegance (e.g. fading to tablets and colored solutions)
 Reduction of bioavailability (e.g. ageing of tablets resulting in a change in dissolution
profile).
 Production of potential toxic materials (e.g. breakdown products from drug degradation)
Objective of drug stability
 To determine maximum expiration date/shelf life.
 To provide better safety to the patients.
 To prevent drug product from different kind of instability.
 To provide better storage condition.
 To determine the packaging components.
 To gather information during preformulation stage to produce a stable product.

6. Reference:
1. http://cst-kh.edu.ps/staff/mabujamee/wp-content/uploads/2010/10/Unit-4-Drug-
Stability.pdf
2. https://www.slideshare.net/JalalUddin10/drug-stability-consideration-and-degradation
3. https://www.slideshare.net/WilwinEdara/drug-stability-29805447