NF IVIV Flashcards

0
Q

Standardised conditions 3

A

Temperature
Solid-liquid interface
Media composition

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1
Q

Biopharmacuetical def of dissolution

A

amount of active ingredient (in solid dosage form) the is dissolved per unit time (under standardised conditions)…

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2
Q

Two main purposes of dissolution testing

A

QC and predict PK in vivo

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3
Q

Dissolution QC purposes 4

A

Batch reproducibility
Shelf life stability
Batch release
Assures changes to manufacturing process do not impact performance (requires BE study)

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4
Q

Predict PK in vivo purposes

A

Guide formulation selection, design and scale-up during

development

– set specifications for API form and particle size

– Guide bioequivalence strategy

– Biowaiver

– In vitro-in vivo correlations

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5
Q

The main factors influencing dissolution

A

Testing Conditions
Drug Formulation
Drug properties

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6
Q

Condition factors influencing dissolution 3

A

Apparatus
Method parameters
Dissolution medium

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7
Q

Formulation actors influencing dissolution 3

A

Compositon
Manufacturing process
M/r?

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8
Q

Drug properties influencing dissolution5

A
Solubility in dissolution medium
Hydrophilic/hydrophobic
Shape/size
Crystalline/amorphous
Polymorphs present?
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9
Q

Phycoco,logical conditions affecting dissolution

A

Properties of GI fluids (composition, pH)

� Gastric emptying (especially for non

disintegrating systems)

� Intestinal transit time

� GI motility and hydrodynamic patterns

� GI enzymes

� Fasted state/ Fed

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10
Q

The media considerations

A

Buffers
Media proposed by pharmacopeia
Bio relevent media

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11
Q

Hydrodynic conisidrations 5

A
Design if apparatus
Agitation intensity
Flow volume
Viscosity if medium
Formulation/drug location
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12
Q

pH of fasted/fed small intestine

A

Fasted 6.8

Fed 5

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13
Q

Bio relevant media types

A

Milk (fed stomach)

Fasted/fed state simulated gastric/intestinal/colonic fluid

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14
Q

Two closed testing apparatus

A

USP apparatus I (rotating basket)

USP apparatus II (rotating paddle)

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15
Q

Advantages of closed system ap 3

A

Simple
Robust
Adequately standardised
(Per infant incubation of dosage form in the SAME medium)

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16
Q

Disadvantages of closed app 3

A

Homogenising
Dispersion
agglomeration

17
Q

Open system appparatus

A

USP AP III (cylinder bio-dis)

USP AP IV (flow through cell)

18
Q

Advantages of open systems 3

A

Multiple pH levels/sequential changes
Residence time in GI
Hydrodynamics in GI

19
Q

Ap IV can be used for

A

Specific dosage forms

Multi particulate or suspensions

20
Q

FDA definition of IVIVC

A

Mathematic model describing the relationship between in vitro property and relevant in vivo response

Generally:
In vitro: rate/extent of dissolution/release
In vivo: plasma drug conc/amount absorbed

21
Q

BA

A

Rate and extend to which an active drug is absorbed from the drug product and becomes available at the site of caution

22
Q

BE

A

Absence if significant difference in BA in pharmaceutical alternatives
(Administered at same molar dose + similar conditions)

23
Q

Which level can be used to justify changes

24
What sort of change can be justified?
``` Manufacturing site Method Raw materials Minor formulation Strength ```
25
Level a usually plots
Release v absorption
26
Level b usually plots
Mean dissolution time V Mean residence time OR mean in vivo dissolution time
27
Weakest correlation
Level c
28
Level c usually plots
Dissolution time point Vs AUC tmax or Cmax
29
Level c is a ... point relationship that .... reflect the entire shape of the curve
Single point | Does not
30
Levee c is useful.,.
In early stages of formulation development when pilot forms selected
31
Multiple level c can be used to justify a biowaiver?
Yes
32
Multiple level c relates
One or more PK parameters to amount dissolved at several time points (at least three)
33
Development of level a correlation
1 develop formulations with different release rates 2 perform in vivo dissolution studies (determine in vivo plasma concentration profiles) 3 estimate absorption time course for each 4 establish model between IVIV variables 5 predict plasma concentration using model
34
How to determine the internal predictability?
Use IVIVC to predict each formulations plasma concentration | Compare observed and predicted using % predicted error
35
Ideal %PE
<15%
36
Equation for %PE
%PE = (AUCobeserved - AUCpredicted/AUCobservered) x100
37
For external predictability PE must be
<10
38
5 applications of IVIVC
•in place of additional bioavailability studies • assist in validating or setting dissolution specifications (based on the performance of the biobatch in-vivo) • Biowaiver - new formulation (the mechanism of drug release should remain the same;) • Biowaivers - manufacturing site, equipment, manufacturing process, and formulation composition. • IVIVC: reduce the number of human studies during the formulation development, shortens time, economizes the resources and leads to improved product quality
39
Limitations
first-pass metabolism in the GI tract Site-dependent absorption • absorption rate-limited * food effects, disease state, healthy volunteers * inter- and intra-subject variability
40
Bio classes where IVIVC expected
I (high high) - if dissolution is rate limiting step | II (high perm, low sol)