Quiz 2 Flashcards
Gas to Liquid is what process?
Condensation: apply pressure or decreasing temperature which decreases the intermolecular distance which means that the molecule stick closer together
Liquid to Gas is what process?
Vaporization: apply pressure or increasing heat/energy increases the intermolecular distance which means molecules has more room to move and more kinetic energy
Liquid to Solid is what process?
Freezing/Fusion: decrease heat/energy which decreases the intermolecular distance which means that the molecule stick closer together
Solid to Liquid is what process?
Melting: increase heat/energy which increases the intermolecular distance which means that the molecule are farther apart and has more kinetic energy
Sublimation
process by which a solid changes directly into a gas without passing through the liquid phase. This occurs when the molecules within a solid have enough energy to overcome the forces holding them together and transition directly into the gas phase
Deposition
Deposition is the process in which a gas changes directly into a solid without passing through the liquid phase. It’s essentially the reverse of sublimation. Deposition occurs when gas molecules lose enough energy for the intermolecular forces to pull them together into a solid structure.
How is supercritical fluid formed?
When pressure is applied excessively and temperature is increased above the critical point, supercritical fluid forms
Maxwell-Boltzmann distribution
(fraction of gas molecules possessing a particular energy) shown in Fig. 2.8 tells that range of distribution decreases exponentially with increase in energy
Gay-Lussac’s Law and Charles’s Law: (V1)(T1) = (V2)(T2)
the volume of a gas is directly proportional to its temperature
Boyle’s Law: (P1)(V1) = (P2)(V2)
inversely proportional relationship
between P and V at constant T. if pressure is decreased 4 times (i.e., P2 = P1/4) volume
will increase 4 times (i.e. V2 = 4V1)
Clausius-Clapeyron: states the relationship between vapor pressure and
absolute temperature
log (P2/P1) = deltaHv (T2 - T1) / (2.303)(8.314 J/mol*K)(T2)(T1)
Degree of Freedom
F = C - P + 2
How does crystals form?
nucleation - one point where all solid molecule can be deposited
What are the factors that influence crystal growth
solvent, temperature, and impurity
Should a pharmaceutical process transition a drug into its less stable polymorph?
no
Allotropism
Existence of an element in more than one crystalline form; e.g. diamond and
graphite are allotropes of carbon
Polymorphism
Same substance but different crystalline forms. They are characterized by different chemical properties such as different melting point, stability, solubility, X-ray diffraction pattern. If it is due to change in conformation, conformational polymorphism.
Polyamorphism
an amorphous solid can exist in two or more distinct amorphous forms. The different amorphous forms may have variations in density, atomic arrangement, or other physical properties, even though the material remains in an overall disordered, non-crystalline state. These differences can arise from changes in temperature, pressure, or other environmental conditions.
Monotrops
one polymorph is stable under all conditions, while the other polymorph is either unstable or less stable. This means that if the less stable polymorph is formed, it will eventually convert to the more stable form over time, given the right conditions.
Enantiotrops
different polymorphs are stable at different temperature ranges. This means that at a certain temperature, one polymorph will be stable, but as the temperature changes, another polymorph becomes the stable form.
Pseudopolymorphs
Polymorphs containing solvents: Examples: lamivudine methanol solvates and scopolamine HBr hydrate
What is the difference between solvates and anhydrates solids?
solvates: dissolves faster, lower melting point, less stable
anhydrous solid: dissolves slower, higher melting point, more stable
Why are tablets made by compression and not drying?
Tablets are made by compressing drug granules. While drying the granules the drug may convert to less soluble polymorph especially when heat or prolonged exposure to certain conditions is involved, there is a risk that the drug may undergo a polymorphic transformation. This can result in the formation of a less soluble polymorph, which can negatively impact the drug’s bioavailability, reducing its therapeutic effectiveness
Drug class of Acetaminophen
Antipyretic, analgesic
Drug class of Famotidine
Histamine H2 receptor antagonist,
Drug class of Piroxicam
NSAID (non-steroidal anti-inflammatory
drug)
Drug class of Norfloxacin
Broad spectrum antibiotic used in prostrate and urinary tract infection
Drug class of Chloramphenicol palmitate
Broad spectrum antibiotic; due to side
effects used only in serious infection for
which less toxic antibiotic is not working
Drug class of Ritonavir
Protease inhibitor, anti-HIV
Amorphous solids
more soluble, dissolves faster, No well-defined conformation, isotropic, tend to flow easily when subjected to
pressure
In drug dosage form development, is metastable drug or stable form of drug preferred?
Generally metastable drugs capable of sustaining the processes involved in drug
dosage form development is preferred over stable form of a drug
Isotropic
similar properties when measured in all direction
Anisotropic (except cubic crystals)
properties vary depending on the direction in which they are measured
The crystalline and amorphous solids are characterized by
a. melting point and heat of fusion, respectively
b. freezing point and heat of fusion, respectively
c. melting point and glass transition temperature, respectively
d. glass transition temperature and melting points, respectively
c. melting point and glass transition temperature, respectively
Crystalline solids are characterized by a well-defined melting point, where they transition sharply from a solid to a liquid state.
Amorphous solids do not have a sharp melting point; instead, they are characterized by a glass transition temperature (Tg), which is the temperature range where they gradually transition from a hard, glassy state to a more rubbery or viscous state.
The glass transition temperature for an amorphous solid is the mid-point of the transition
in which the solid converts from a glassy to rubber state.
a. True
b. Depends on atmospheric condition
c. False
d. There is nothing like glass transition temperature
a. True
- The critical temperature and pressure for CO2 gas are 31oC and 74.9 atm, respectively. Can you liquefy CO2 stored at 100oC by applying pressure only?
a. No
b. Yes
a. No.
CO₂ cannot be liquefied at 100°C by applying pressure alone because it is above the critical temperature of 31°C. Above this temperature, CO₂ exists as a supercritical fluid regardless of pressure.
why is nitroglycerin formulated with macromolecules e.g. PEG, PVP, and MCC
it is highly volatile
A gas is stored at 30C and 2.5 atmosphere. What will happen to pressure when the gas will move to a storage maintained at 60C? Given the volume of the gas container is 1.5 liters
Combined gas law: P1V1/T1 = P2V2/T2
Why SFE is a better method for extracting essential oils from natural plant sources than other extraction methods
- Supercritical fluids allow for lower-temperature extractions
- Supercritical fluid extraction exhibits relatively higher selectivity of extracted compounds. This avoids multiple purification steps.
Ideal Gas Law equation
PV = nRT
