Racemization

Definition:

• Racemization is the interconversion of enantiomers (optical isomers) that can lead to changes in biological activity.

Mechanism:

• A chiral molecule can transform into its mirror-image isomer under certain conditions (pH, temperature, etc.).

Examples:

• Example Reaction (Racemization of Amino Acids):

• Thalidomide: One enantiomer is therapeutic, while the other is teratogenic.

• Epinephrine: Converts to inactive isomers at higher pH.

Prevention Strategies:

• Optimize pH and temperature during storage.

• Stabilize formulations using buffers.

• Choose enantiomerically pure drugs if racemization poses a risk.