amorphous solid dispersions Flashcards
what are the two types of molecular arrangement?
ordered crystalline molecular arrangement
disordered amorphous molecular arrangement
what is a polymorph?
different crystal molecular arrangement so different solubility and stability
how is the challenge of a no polymorphs that are soluble enough dealt with?
amorphous form used that are more soluble than crystalline form however they’re less stable
what delivery route is preferred for drug delivery?
oral route
what is does oral delivery need to display?
good solubility and dissolution properties
good absorption through gut
what does bioavailability of a drug?
the amount of drug that enters circulation when enters the body and can have an active effect
what is the journey of drug molecules?
In-Vivo:
dissolution, drug in solution (solubility), permeability (gut wall), blood, site of action, therapeutic effect
In-vitro:
dissolution (in dissolution testing), drug in solution (solubility), permeability (gut wall), blood, site of action, therapeutic effect
what is the table for Biopharmaceutics Classification System?
slide 7
what is the limitation of class 1?
formulation dependent
what is the limitation of class 2?
formulation dependent
what is the limitation of class 3?
Dependent on barrier properties
what is the limitation of class 4?
Formulation and barrier properties dependent
what are some oral formulation approaches for poorly water soluble compounds?
Crystalline Solid Dispersions
Amorphous drug and Amorphous Solid Dispersions
what is the effect of Amorphous drug and Amorphous Solid Dispersions?
disrupts crystalline ordered structure to form disordered amorphous structure so dissolution happens faster
what is the effect of Crystalline Solid Dispersions?
‘ordered particles of drugs are stable in solid water-soluble polymer matrix’
what happens when amorphous state reached?
increase in solubility and dissolution rate
decrease in physical stability
what is glass transition temperature?
Tg- physical transition in amorphous materials from brittle to rubbery state
what does a low Tg mean?
the lower the Tg the less stable the amorphous is
what is spray drying?
fast solvent evaporation
‘Needs acceptable solubility of drug in low boiling solvent required.’
what is hot melt extrusion?
no solvent needed
temperature and shear required for degradation
what are the main manufacturing methods for solid dispersions?
heat based methods
solvent based methods
