JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Pharmacy III INDUSTRIAL PHARMACY-I Previous Question Paper (July/August - 2023 - R17)

Racemization is the process by which one enantiomer of a chiral compound is converted into a mixture of both enantiomers, resulting in a racemic mixture. This occurs when the chiral center of a molecule loses its optical activity through chemical or physical means, such as changes in pH, temperature, or solvent polarity.

In drug action, racemization can significantly alter pharmacological activity. Since biological receptors are stereospecific, one enantiomer may be therapeutically active while the other is inactive, less active, or potentially toxic. Consequently, racemization during manufacturing or storage can reduce the potency of a drug or lead to unpredictable side effects, necessitating strict control over formulation stability to maintain the intended therapeutic profile.

The differentiation between crystalline and amorphous forms is primarily based on the arrangement of molecules and their physical properties:

• Molecular Arrangement: Crystalline solids possess a highly ordered, repeating three-dimensional internal structure known as a crystal lattice. In contrast, amorphous solids lack long-range order and exhibit a random, disordered arrangement of molecules, similar to a supercooled liquid.
• Melting Point: Crystalline forms have a sharp, well-defined melting point. Amorphous forms do not have a specific melting point; instead, they soften gradually over a temperature range as they transition from a solid to a viscous state.
• Solubility and Stability: Crystalline forms are generally more thermodynamically stable and less soluble. Amorphous forms are metastable, often exhibiting higher solubility and faster dissolution rates due to their higher internal energy, though they are more prone to recrystallization over time.