316 Q2

ndifranco94's version from 2015-09-02 03:20


Question Answer
Gas Phase DD SystemsInhaler, Anesthesia, Nasal Spray
Liquid Phase DD Systemscough syrup, IV formulations
Freeze Dryingused to remove liquid
Why freeze drying instead of evaporation?proteins break down at high temps
AerosolSuspension of fine drug particlees or liquid droplets in air
How much pressure is needed to release an aerosol?Heat of vaporization
Gas -> SolidFreeze drying
How to calculate heat of vaporizationClasius-Clapeyron equation
Propellantliquid in aerosol container, is a gas under atmospheric conditions
Ex. of propellantshydrocarbons, CFCs, hydroFCs, gas (N2, CO2), H2O
Hydrocarbons disadvantageflammable, Ex. propane, butane
CFCs disadvenvtl concerns
What can aerosols deliver?drugs, proteins, nucleic acids through pulmonary and nasal routes
Crystalline solidorderly arrangement, definite melting point
Solvatesresidual solvent molecules trapped in the crystalline lattice of a drug or other solid crystals
Ex. of a solvateDMSO
Polymorphismsolid substances that exist in more than one crystalline form (allotropic), but have same chem. structure
Polymorhism stabilitycan spontaneously convert from metastable to stable form
Polymorphism propsdiff melting points, solubilities, x-ray crystallography
Causes of polymorphismIntermolecular interactions (ion-ion, dipole-dipole, hydrogen bonding), Solvation
Polymorphism changes what pharma propssolubility, stability, bioavailability, pharm activity
Amorphousfaster dissolution, better bioavailability, better activity -> lower IMF
Do we want high or low melting pt?Low b/c indicates lower IMF
How to lower melting pt of alkanes?odd # of C -> less packing, lower IMF, more solubility
Why is COOH melting pt higher than alkanes?Hydrogen bonding inc IMF
Molar heat of fusion (delH)heat absorbed when 1 mole of solid melts/heat liberated when it freezes
Smecticmobile in 2 directions, rotate about 1 axis
Nematic (thread phase)align in one direction and rotate about one axis
Lyotropic liquid crystalslipid bilayers, micelles --> exhibit liquid crystal props in certain conc range
Supercritical Fluidmesophase formed when gas is held @ P and T above critical pt
Props of superciritcal fluidpermeate solids, high density (regulated by P), can dissolve compounds
Applications of supercritical fluidextraction, crystallization, prepare drug formulations (NP and microspheres)
Adv of supercritical fluidlow pressure extraction, selective, lower NRG req, lower viscosity
Differential Scanning Calorimetrymeasures diff in heat required to inc temp of sample and reference as fxn of temp, CAN SHOW POLYMORPHS
Write an endothermic DSC
What do we want in a DSC?less low temp changes --> more stable