Sample interview questions: Discuss the principles of thermodynamics in the context of pharmaceutical research.
Sample answer:
1. First and Second Laws of Thermodynamics:
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First Law: Total energy in a system remains constant. In pharmaceutical research, this means the energy input into a reaction must equal the energy output of the reaction, considering heat, work, and changes in internal energy.
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Second Law: Entropy of an isolated system always increases or remains constant. In pharmaceutical research, this means that reactions tend to proceed toward a more disordered state, influencing reaction rates, equilibrium, and spontaneity.
2. Phase Transitions and Chemical Reactions:
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Phase Transitions: During phase transitions (e.g., melting, boiling, sublimation), there is a change in the physical state of a substance, accompanied by heat absorption or release. This knowledge helps in designing processes involving heating, cooling, or crystallization in pharmaceutical manufacturing.
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Chemical Reactions: Chemical reactions involve energy changes, which can be exothermic (releasing heat) or endothermic (absorbing heat). Thermodynamic parameters like enthalpy (ΔH) and entropy (ΔS) help predict reaction feasibility and heat management strategies.
3. Solubility and Partitioning:
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Solubility: The solubility of drugs in different solvents is crucial for formulation development and drug delivery. Thermodynamics can help predict solubility based on intermolecular interactions, temperature, and pressure.
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Partitioning: Partitioning of drugs between different phases (e.g., octanol and water) is vital in understanding drug absorption, distribution, and metabolism. Partition coefficients are thermodynamic measures that aid in predicting these processes.
4. Stability and Degradation:… Read full answer