Page 71 - Quality control of pharmaceuticals (07-PA 704)

approach is known as a prodrug strategy. The hydrolysis of aspirin also produces
acetic acid as a product. In the poor storage of aspirin tables, a smell of vinegar that
pervades over time is a sign that hydrolysis is occurring.
Another prodrug example includes the angiotensin-converting enzyme inhibitor
enalapril, whose ester is hydrolysed in vivo to generate the active carboxylic acid
derivative enalaprilate (enalaprilate being used as an intravenous form of enalapril
for hypertensive emergencie )

(2) Oxidation

Removal of an electropositive atom, radical or electron, or the addition of an
electronegative atom or radical. Oxidation is controlled by environment i.e., light,
trace elements, oxygen and oxidizing agent.
Types of oxidation:
Auto oxidation:
Oxidation in which the oxygen presents in the air involved. This process proceeds
slowly under the influence of atmospheric oxygen. Examples: oils, fats and
unsaturated compounds.
Photo oxidation:
Oxidation in which removal of the electron is involved without presence of O2
Examples: adrenaline, riboflavin and ascrorbic acid.
Some Functional Groups Subjects to oxidation:

Prevention of oxidative deterioration
• Exclusion of oxygen this is pretty obvious: if oxygen in the air is causing the
oxidation, then exclusion of oxygen from the formulation will minimize