Exam 2: Definitions Flashcards
Rate of dissolution
Amount of drug substance that goes in solution per unit time under standardized conditions of liquid/solid interface, temperature, and solvent composition
Tablet
Very fine powder compressed into a single dosage unit
Capsule
Solid dosage forms in which the drug substance is enclosed within a hard/soft soluble shell (usually formed from gelatin)
USP definition of IVIC
Establishment of rational relationship between a biological property or a parameter derived from a biological property produced by a dosage form and physicochemical property of same dosage form
FDA definition of IVIC
Predictive mathematical model describing the relationship between in vitro property of dosage form and a relevant in vivo response
Mixer: Drum
Mixing mech: diffusive Segregation: bad Axial mixing: bad Ease of emptying: bad Segregation on emptying: bad
Mixer: V-Mixer
Mixing mech: diffusive Segregation: bad Axial mixing: bad Ease of emptying: good Segregation on emptying: bad
Mixer: Cone
Mixing mech: diffusive Segregation: bad Axial mixing: bad Ease of emptying: good Segregation on emptying: bad
Mixer: Ribbon
Mixing mech: convective Segregation: good Axial mixing: slow Ease of emptying: good Segregation on emptying: fair
Mixer: Fluidize
Mixing mech: convective Segregation: fair Axial mixing: good Ease of emptying: good Segregation on emptying: good
Mixer: Screw
Mixing mech: shear Segregation: bad Axial mixing: good Ease of emptying: good Segregation on emptying: bad
Level A IVIVC
Point-to-point relationship between in vitro dissolution time and the in vivo input rate
Level B IVIVC
Mean in vitro dissolution time compared to mean in vivo dissolution time
(Multiple) Level C IVIVC
Single point comparison of drug dissolved to one PK parameter
Ex) T50% linked to AUC/Cmax/Tmax
How to calculate % Prediction Error (PE)
%PE = [(AUCobserved - AUCpredicted)/AUCobserved] * 100 = [(Cmaxobserved - Cmaxpredicted)/Cmaxobserved] *100
How to calculate rate of dissolution? (Know what each variable stand for)
dC/dt = k1A(Cs - Ct) = DA/Vh (Cs - Ct)
How to calculate dissolution rate at sink conditions? (Know conditions and variables)
dC/dt = k2ACs
Sink conditions vs Non-sink conditions
Sink conditions: complete dissolution of drug, excess solubilizing capacity of the dissolution medium (zero order)
Non-sink conditions: non-excess solubilizing capacity of dissolution medium (first order)
Absolute surface area vs Effective surface area
Absolute: total SA of particle
Effective: SA of particle exposed to dissolution medium
How to calculate D value for microbial death?
D = T/[log(original)-log(remaining)]
Dissolution
Process in which a solid substance solubilizes in a given solvent
