Drug degradation of physical pharmacy

1. Drug degradation
Md. Aminul Islam
Department Of Pharmacy
World University Of Bnagladesh

2. Definition of drug degradation
The change of a chemical compound into a less complex
compound.

3. Types of drug degradation
Drug degradation can be divided two major types:
• Physical degradation
• Chemical degradation

4. Physical degradation
Degradation which results into the change of physical nature
of the drug.

5. Types of physical degradation
Types of physical degradation are as under
• Loss of volatile components
• Loss of H2o
• Absorption of H2o
• Crystal growth
• Polymorphic change
• Color changes

6. Types of physical degradation
1. Loss of volatile components: volatilecomponents such as
alcohol ether, Iodine, volatile oils, camphor, menthol etc.
Example:
• Aromatic waters
• Elixirs
• Spirits
2. Loss of H2o:This tendency depends on temperature and
humidity of surrounding environment.

7. Types of physical degradation
3. Absorption of H2o: Hydroscopic drug absorb the water from external
atmosphere causing the physical degradation. Depend on temperature
and humidity of surrounding environment.
4. Crystal growth: In solution after super saturation crystal growth
occur. Reason may be the fall in temperature and consequent decrease
in solubility of solution. Exam injection of calcium gluconate.
5. Polymorphic change: Polymorphic change crystal forms are change.
A stable crystal forms loosens. This may cause alteration in solubility
and possibly crystalline growth in aqueous suspension.

8. Chemical degradation
Change in the chemical nature of the drug is called as
chemical degradation. Chemical degradation of a dosage
form occurs through several pathways like hydrolysis,
oxidation,decarboxylation, photolysis, racemization. Which
may lead to lowering of therapeutics agent in the dosage
form, formation of toxic product, decreased bioavailability.

9. Hydrolysis
It is define as the reaction of a compound with water.
• Most important in system containing water such as
emulsion, suspension, solution , etc.
• Also for drugs which are affected by moisture from
atmosphere
• In this active drug is decomposed with solvent.

10. Types of hydrolysis
1. Ionic hydrolysis
2. Molecular hydrolysis

11. THANK YOU