PHM 387M Thermodynamics in Pharmacy

Questions and Answers

What does the DSC thermogram help to determine about drug interactions?

The kinetic stability of the drug.

The compatibility of excipients with drugs. (correct)

The pharmacological properties of the drug.

The toxicity levels of the drug.

In a DSC process, which of the following phases is primarily an exothermic process?

Glass Transition

Crystallization (correct)

Cross-Linking

Melting

According to the Second Law of Thermodynamics, what happens to the entropy of a system at equilibrium?

It can only decrease.

It always increases.

It remains constant at zero change. (correct)

It becomes negative.

Which of the following processes is characterized by the system moving towards a state of randomness?

Irreversible spontaneous process Signup and view all the answers

What is one effect of the heat flow illustrated in a composite graph of enthalpies?

It reflects energy changes associated with different physical processes. Signup and view all the answers

Which fundamental concept relates entropy and enthalpy in pharmaceutical systems?

Gibbs Free Energy principle Signup and view all the answers

What is the primary learning objective relating to drug solubility?

To explain poorly water-soluble drugs' behavior Signup and view all the answers

Which technique is emphasized for understanding enthalpy in drug-related processes?

Differential scanning calorimetry Signup and view all the answers

What will students not be assessed on during the first two weeks of classes?

Calculations involving enthalpy Signup and view all the answers

How will students access reading materials for lectures?

Posted on Canvas every Friday Signup and view all the answers

What does a positive change in enthalpy (ΔH > 0) indicate about a process?

The process absorbs heat. Signup and view all the answers

What is a common practice question posed in relation to pharmacy operations?

How often temperature is recorded Signup and view all the answers

Which of the following statements about enthalpy is TRUE?

Change in enthalpy at constant pressure reflects heat exchange with the surroundings. Signup and view all the answers

What innovative tool can be used for in-poll responses during classes?

The UT Instapoll on Canvas Signup and view all the answers

Which anti-HIV drug listed is the most enthalpically favored for binding to HIV protease?

Nelfinavir Signup and view all the answers

What is indicated as not required during the first two weeks of the course?

Calculating drug dosages Signup and view all the answers

For the drug binding to the HIV protease, what does a negative change in enthalpy (ΔH < 0) imply?

The process releases heat to the surroundings. Signup and view all the answers

Which of the following drugs has the least favorable enthalpy for binding to HIV protease?

Ritonavir Signup and view all the answers

In the equation ∆E = q + w, what does 'w' represent?

The work done on or by the system. Signup and view all the answers

What is the relationship between a closed system's change in internal energy and its surroundings?

Energy is conserved; changes in system energy result in equal changes in surroundings. Signup and view all the answers

Which of the following best represents an endothermic process related to enthalpy?

Dissolution of a drug that absorbs heat from the environment. Signup and view all the answers

If a system is enthalpically hindered, what does this imply about the process?

The process requires energy input and is less favorable. Signup and view all the answers

What does the Zeroth Law of Thermodynamics state about bodies A, B, and C?

If A and B share the same temperature, then they are in thermal equilibrium with each other. Signup and view all the answers

How does the Zeroth Law of Thermodynamics influence the storing of medications?

It determines that medications at some temperatures can become ineffective. Signup and view all the answers

If a vaccine is left out of refrigerated storage, which outcome is correct assuming thermal equilibrium?

The temperature of the vaccine will be the same as the surrounding environment. Signup and view all the answers

What does the First Law of Thermodynamics imply about energy?

Energy can only be transformed into different forms but not destroyed. Signup and view all the answers

Which scenario illustrates a misunderstanding of thermal equilibrium?

Considering two rooms with different temperatures to be in equilibrium. Signup and view all the answers

In terms of energy transfer, what defines work in thermodynamics?

The transfer of mechanical energy to the surroundings. Signup and view all the answers

When is heat defined as thermal energy in transit?

It describes energy moving between systems due to a temperature difference. Signup and view all the answers

Which statement about internal energy is most accurate?

It is determined by microscale interactions in the system. Signup and view all the answers

What is a common misconception about the effects of temperature on medication effectiveness?

All medications require the same storage temperatures. Signup and view all the answers

What happens to the internal energy of a system when work is done on it?

The internal energy increases. Signup and view all the answers

What is the primary reason heat pads feel warm during the process of melting sodium acetate?

The system releases heat because of the formation of stronger ionic bonds. Signup and view all the answers

What type of reaction occurs when ammonium nitrate dissolves in water?

Endothermic reaction, where heat is absorbed. Signup and view all the answers

What does Differential Scanning Calorimetry (DSC) measure regarding drug processes?

The difference in heat flow rate between a sample and inert reference. Signup and view all the answers

Which of the following is NOT a use of Differential Scanning Calorimetry (DSC) in drug formulation?

Determining the solubility of active ingredients. Signup and view all the answers

What occurs to the ionic bonds during the dissolution of ammonium nitrate in water?

Ionic bonds are broken and replaced with weaker polar interactions. Signup and view all the answers

What is the role of the thermoelectric disc in a DSC setup?

To heat the sample uniformly to prevent uneven thermal profiles. Signup and view all the answers

In the context of heat pads, what primarily causes the heat sensation felt when sodium acetate transitions from liquid to solid?

Release of energy due to bond formation that is more stable. Signup and view all the answers

Which of the following best describes a characteristic feature of exothermic processes?

They release heat, resulting in an increase in surrounding temperature. Signup and view all the answers

What is the significance of paralleling a sample with an inert reference in DSC?

To compare heat flows and ensure accurate measurement. Signup and view all the answers

What type of interaction occurs when sodium acetate crystallizes from a liquid solution?

Transition to a solid state that releases heat through ionic bonds. Signup and view all the answers

Study Notes

Course Information

Course: PHM 387M - Physical and Chemical Principles of Drugs (Fall 2024)
Office hours listed on the master contact sheet on Canvas starting next week after Labor Day.
No assessments during the first two weeks (Aug 26 and Sept 2 readings).
Upcoming lecture readings will be available on Friday.
UT Instapoll available on Canvas for in-class polling responses.

Thermodynamics in Pharmacy

Basic laws of thermodynamics are essential for understanding pharmacy practices.
Key concepts include entropy, enthalpy, and Gibbs Free Energy in pharmaceutical systems.

Zeroth Law of Thermodynamics

Defines thermal equilibrium: If bodies A and B are in thermal equilibrium with body C, they are also in thermal equilibrium with each other.
Impacts medication storage; maintaining correct temperatures is crucial.

Internal Energy, Work, and Heat

Internal energy relates to the microscale but is measurable via work and heat macroscopically.
Work is the mechanical energy transfer; primarily focuses on pressure-volume work.
Heat is defined as thermal energy in transit.

First Law of Thermodynamics

Energy cannot be created or destroyed; it can only change forms.
The overall energy in a closed system remains constant: ΔE = q + w.

Enthalpy

Enthalpy (H) measures the heat content of a process; change in enthalpy reflects heat absorbed or released.
Enthalpically favored processes (ΔH < 0) release heat (exothermic), while those that absorb heat (ΔH > 0) are endothermic.

Enthalpy in Drug Processes

Example: Enthalpy of binding of anti-HIV drugs to HIV protease shows different binding affinities based on ΔH values.
Understanding which drugs are most/least enthalpically favorable aids in drug development.

Exothermic Reactions and Drug Dissolution

Heat pads utilize the exothermic crystallization of sodium acetate; they feel warm as energy is released.
Ice packs leverage endothermic processes, like ammonium nitrate dissolution, leading to cooling effects.

Differential Scanning Calorimetry (DSC)

DSC is a technique for measuring heat flow differences in drug-related processes, critical for thermal analysis.
Applications include measuring melting points (ΔHfus), mixing, solvation enthalpy, and assessing compatibility of excipients with drugs.

Second Law of Thermodynamics

Concerns the probability and direction of spontaneous processes, emphasizing that systems tend toward increased randomness (entropy).
At equilibrium, the net entropy change between a system and its surroundings equals zero, confirming the spontaneous nature of irreversible processes.

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Description

This quiz covers fundamental thermodynamic principles essential for pharmacy practices, including the Zeroth Law of Thermodynamics, internal energy, work, and heat. Understanding these concepts is critical for medication storage and the overall pharmaceutical system. Test your knowledge on how these principles apply to drug development and storage methods.