DRUG DELIVERY 1 chapter 2 States of Matter Related to Pharmaceutical Formulations

Vocabulary-style flashcards covering states of matter, intermolecular forces, and related physical properties relevant to pharmaceutical formulations.

States of matter

The solid, liquid, and gaseous forms of matter, distinguished by particle arrangement, kinetic energy, and intermolecular forces.

Potential energy diagram for attractive forces

A graph showing how potential energy varies with distance between molecules when attractive intermolecular forces act.

Potential energy diagram for repulsive forces

A graph showing how potential energy increases as molecules approach each other due to repulsion.

Attractive forces

Intermolecular forces that pull molecules toward each other.

Repulsive forces

Intermolecular forces that push molecules apart at close distances.

Cohesive forces

Attractions between like molecules that hold a substance together.

Adhesive forces

Attractions between unlike molecules, such as a liquid to a surface.

Van der Waals forces

A family of intermolecular forces including dipole-dipole, dipole-induced dipole, and London dispersion forces.

Dipole-Dipole forces (Keesom)

Forces between polar molecules with permanent dipoles; energy typically 1–7 kcal/mol.

Dipole-Induced Dipole forces (Debye)

A polar molecule induces a temporary dipole in a nonpolar molecule; weaker than dipole-dipole (about 1–3 kcal/mol).

Induced Dipole-Induced Dipole forces (London dispersion)

Temporary attractions due to instantaneous dipoles in nonpolar molecules; 0.5–1 kcal/mol; key for liquefaction of gases.

Ion-Dipole forces

Interactions between ions and polar molecules; typically 1–7 kcal/mol.

Hydrogen bond

A strong dipole-dipole interaction between a hydrogen atom bound to an electronegative atom and another electronegative atom.

Hydrophobic interactions

Nonpolar molecules aggregate in water due to solvent effects and dispersion forces.

Gaseous state

State with high kinetic energy, weak intermolecular forces; fills container; highly compressible; no fixed shape.

Boyle's law

PV = constant for a fixed amount of gas at constant temperature.

Charles' law

Volume is proportional to temperature (V ∝ T) at constant pressure for a gas.

Ideal gas law

PV = nRT; combines Boyle's and Charles' laws to describe gas behavior.

Kinetic energy (gas)

For 1 mole of an ideal gas, KE = (3/2)RT.

Vapor pressure

Equilibrium vapor pressure of a liquid above its surface; depends on temperature and is reached when rate of vaporization equals condensation.

Boiling point

Temperature at which a liquid's vapor pressure equals the surrounding atmospheric pressure.

Liquid state

Definite volume, takes shape of container; denser than gas; flows; has vapor pressure and surface tension.

Solid state

Fixed shape, nearly incompressible; strong intermolecular forces; low kinetic energy; atoms vibrate in place.

Melting point

Temperature at which a solid becomes a liquid; related to the strength of intermolecular forces.

Heat of fusion

Energy required to melt a solid at its melting point.

Heat of vaporization

Energy required to vaporize a liquid at its boiling point.

Sublimation point

Temperature at which a solid transitions directly to a gas without becoming liquid.

Surface energy

Energy associated with the surface of a solid, affecting interfacial phenomena and properties like wettability.

Hardness

Resistance of a solid to scratching or permanent deformation.

Elastic properties

Ability of a solid to deform under stress and return to its original shape when the stress is removed.

Porosity

Fraction of a solid's volume that is void space; important for tablet formation and drug loading.

Phase diagram (eutectic mixture)

Diagram showing the composition where a mixture has the lowest melting point, important in pharmaceutical solids.