factors effecting the rate of drug degradation.

1. FACTORS AFFECTING THE
DEGRADATION OF DRUGS
Presented to:
Ma’am Maria
Presented by :
Urooj Umer
CMS no:404570

2. contents
The contents are:
1. Drug Degradation
2. Types of drug degradation
 Physical degradation
 Chemical degradation
 Microbial degradation
3. Factors Affecting the Rate of drug
degradation
 ph
 Complexation
 Surfactants
 Presence of heavy metals
 Light
 Humidity/ Moisture

3. DEGRADATION
Drug degradation is defined as:
THE CONDITION OR PROCESS OF
DEGRADING OR BEING
DEGRADED
OR
It is also defined as:
DECLINE TO A LOWER QUALITY
CONDITION OR LEVEL

4. PHARMACEUTIC
AL DEGRADATION
Pharmaceutical degradation is defined as:
THE INCAPACITY OR INCAPABILITY
OF A PARTICULAR FORMULATION
IN A SPECIFIC CONTAINER TO
REMAIN WITHIN A PARTICULAR
CHEMICAL ,MICROBIOLOGICAL ,
THERAPUTICAL, PHYSICAL ,
TOXICOLOGICAL SPECIFICATION

5. TYPES OF DEGRADATION
TYPES OF
DEGRADATION
DEFINITIONS FACTORS AFFECTING
THEIR RATE OF
DEGRADATION
PHYSICAL • This degradation results in
change in nature of
physical nature of drug.
• Change in physical
appearance of drug
• Loss of volatile components
• Loss of water
• Crystal growth
• Polymeric changes
• Changes in color
CHEMICAL • Separation of chemical into
elements or simpler
compounds.
• Change in chemical nature of
drug.
• Hydrolysis
• Oxidation
• Decarboxylation
• Isomerization
• polymerization
MICRO-
BIAL
• It is the use of bioremediation
and biotransformation to
harness the naturally
occurring ability of drug.
• No addition of antimicrobial
substance as presentative
• No proper storage
containers

6. FACTORS AFFECTING THE RATE OF
DEGRADATION
•pH:
The acidity or alkalinity of a solution has a profound
influence on the decomposition of drug.
pH influence the rate of oxidation. The system is less
readily oxidized when pH is low.
As little as 1 pH unit can change ten folds the rate
constant .
STABLE DRUGS pH : 4-8

7.  Graph of pH
pH effect on
aspirin
pH is 2.4
pH effect on
fluorouracil pH is
8.6-9.4

8. • COMPLEXATION
Complexation is the association between
two or more molecules to form non
bounded entity with well defined
stereochemistry
Complex formation reduces the rate of
hydrolysis and oxidation
EXAMPLE:
Caffeine with local anesthetics cause a
reduction in their hydrolytic degradation.

9.  Continue…….
CAFFEINE
STRUCTURE
GRAPH OF
COMPLEXATION

10. • SURFACTANTS
Non-ionic ,cationic and
anionic surfactants when
added to solutions containing
drugs from micelle and drug
particles become trapped in
micelles .
The hydrolytic group such as
OH cannot penetrate this
micelle cover and reach drug
particles , hence Hydrolysis is
decreased
micelle

11.  Continue……

12. • PRESENCE OF
HEAVY METALS
Free radicals such as:
• Copper (Cu')
• Iron (Fe')
• Cobalt (Co')
• Nickel (Ni')
increase the rate of formation of free radicals and
enhance oxidative decomposition.

13. • LIGHT
Extreme light effects the rate of drug degradation by
photolysis.
(Decomposition or separation of molecules by the
action of light)
UV light enhances the photolysis of drug.

14. • MOISTURE /
HUMIDITY
The level of humidity greatly effect the degradation of
drugs. Degradation of tablets or capsules start when they
are exposed to moisture.
Humidity enhances the hydrolytic decomposition of drug.
The humidity conditions that lead to unexpected change
in physical state of tablet :
• Hydration/dehydration
• Melting point
• Boiling point

15. CONCLUSION
 A pharmaceutical product must appear elegant ,
fresh and professional for as long as it remains on
the shelf.
 Dose of active ingredient over time must be ensured.
 Drugs must be protected from photolysis.
 Drugs must be stored at cool and dry place.
 The pH of drugs must be maintained at a narrow
range.

16. REFRENCES
https://www.slideshare.net/drnehalalyaffifi/stability-
of-drug
www.Wikipedia.com
https://www.slideplayer.com
www.linkdin.com
www.google.com.pk
https://www.slideshare .rate of pharmaceutical drug
degradation
Martins Physical Pharmacy and Pharmaceutical
Sciences