Solubility, Dissolution, and Partitioning

These flashcards cover essential terms and concepts related to solubility, dissolution, and partitioning as presented in the lecture notes.

Solubility

The concentration of a solute when the solvent has dissolved all the solute it can at a given temperature.

Miscibility

The ability of two liquids to mix in all proportions, forming a homogeneous solution.

Ksp (Solubility Product Constant)

A constant equal to the product of the equilibrium concentrations of dissolved ions of a salt, each raised to the power of its stoichiometric coefficient.

Weak Electrolyte

A substance that partially dissociates into ions in solution and has a solubility that depends on pH.

Partitioning Law

States that a solute will distribute itself between two immiscible solvents in a way that the ratio of its concentrations is constant for a given solute at a certain temperature.

Noyes-Whitney Equation

An equation that describes the rate of drug dissolution from solid particles into a solution.

pH of Precipitation

The pH above which a drug in solution will precipitate due to low water solubility.

Hydrogen Bonding

An attractive force between a hydrogen atom covalently bonded to a more electronegative atom and another electronegative atom.

Dissolution Rate

The speed at which a drug dissolves in a solvent, often influenced by particle size and agitation.

Dissolution Studies

Tests performed to determine the rate and extent of drug release from a dosage form.

Apparent Partition Coefficient

A partition coefficient that takes into account the ionization of a solute in a solvent system.

Supersaturated Solution

A solution that contains more solute than can be dissolved at equilibrium at a given temperature.

Ionization State

The degree to which a substance dissociates into ions in solution, affected by pH.

Hydrophilic Drug

A drug that has a high affinity for water and dissolves easily in aqueous environments.

Micronization

The process of reducing the size of drug particles to increase their surface area and solubility.

Bioavailability

The fraction of an administered dose of unchanged drug that reaches systemic circulation.

Strong Electrolyte

A substance that completely dissociates into ions in solution, leading to high solubility.

USP (United States Pharmacopeia)

An authority that sets quality standards for medicines, including guidelines for dissolution testing.