Biopharmaceutics and Formulation Development Flashcards

Flashcards covering the Biopharmaceutics Classification System (BCS), physical and chemical modifications for solubility enhancement, and specialized drug delivery technologies.

BCS Class I

Drugs characterized by high solubility and high permeability.

BCS Class II

Drugs characterized by low solubility and high permeability.

BCS Class III

Drugs characterized by high solubility and low permeability.

BCS Class IV

Drugs characterized by low solubility and low permeability.

Micronisation

A technique where reduced particle size increases surface area to improve bioavailability through mechanical methods like grinding, milling, and crushing.

Nanosuspension

A colloidal dispersion of drug particles that are sub-micron in size, stabilized by the presence of a surfactant.

Crystal Habit Modification

The process of altering the crystal structure of an API through crystal engineering, solvates/hydrates formation, or polymorphs to define its physicochemical properties.

Eutectic Mixture

A combination of two or more substances that, when mixed in a specific ratio, melt at a lower temperature than any of the individual components alone.

Eutectic Point

The specific temperature at which a eutectic mixture melts, occurring at a specific eutectic composition.

Solid Solution

A single homogeneous phase where two components are mixed and the drug is molecularly dissolved within the solid excipient matrix.

Interstitial Solid Solution

A condition in a solid solution where solute atoms occupy the space in interstitial positions.

Substitutional Solid Solution

A condition in a solid solution where solute atoms occupy regular lattice sites of the solvent.

Solid Dispersion

A combination of a hydrophilic matrix (such as PEG or surfactants) and hydrophobic drugs dispersed in amorphous or crystalline particles.

Hot-melt method (fusion method)

A preparation method for solid dispersions where the drug and carrier are heated until they melt, rapidly cooled with ice, stirred until solidified, and then processed into tablets.

Solvent evaporation method

A technique where the API and carrier are dissolved in an organic solvent which is then evaporated at low temperatures to prevent drug degradation.

Co-grinding method

A mechanical preparation method for solid dispersions using a blender and a vibration ball mill with steel balls, which does not require organic solvents.

Cryogenic techniques

Methods used to transform a drug into an amorphous nanostructure with high porosity at extremely low temperatures to enhance dissolution speed.

Microemulsion

Clear, transparent, unstable mixtures composed of an aqueous phase, oil phase, surfactant, and co-surfactants.

SEDDS (Self-Emulsifying Drug Delivery Systems)

Isotropic mixtures of oil, surfactant, and co-surfactant that solve low bioavailability problems of poorly soluble drugs.

Inclusion Complexation

A complex developed by the infusion of a non-polar particle or guest particle into the cavity of different particles or an assembly of molecules.

Cyclodextrins

Natural cyclic oligosaccharides composed of 6, 7, or 8 D-glucopyranose monomers linked by $\alpha$-1,4 glycosidic bonds, featuring a lipophilic inner cavity and a hydrophilic outer surface.

$\alpha$-Cyclodextrin

A cyclodextrin composed of 6 glucose units with a cavity diameter of $0.47-0.53\,nm$.

$\beta$-Cyclodextrin

A cyclodextrin composed of 7 glucose units with a cavity diameter of $0.60-0.65\,nm$.

$\gamma$-Cyclodextrin

A cyclodextrin composed of 8 glucose units with a cavity diameter of $0.75-0.83\,nm$.

Hydrotrophy

The use of hydrotropic agents like urea or nicotinamide to solubilize hydrophobic drugs by forming complexes in aqueous solutions.

Co-crystallization

A technique where drugs form crystalline complexes with co-crystal formers through non-covalent interactions to alter solubility profiles.

Prodrug

A chemically modified version of a drug, such as Enalapril maleate, designed to increase aqueous solubility by introducing hydrophilic or ionizable functional groups.

Supercritical Fluid Technology

An eco-friendly method used to reduce particle size by dissolving the drug in an SCF and subsequent crystallization, increasing surface area.

Critical Micelle Concentration (CMC)

The concentration level above which surfactants form micelles and drug solubility increases.

Electrospinning

A process where a drug-polymer solution is spun into nanofibers to create a drug-loaded mat with high surface area for improved oral bioavailability.

Solid Lipid Nanoparticles (SLN)

Biocompatible delivery systems ($50-1000\,nm$) consisting of a solid lipid matrix at room temperature, used for controlled and prolonged drug release.

Polymeric Micellar Carriers

Amphiphilic block co-polymers that self-assemble to form a hydrophobic core for drug encapsulation and a hydrophilic corona/shell for solvation.