using pharmacoscintigraphy to elucidate in vivo ...€¦ · using pharmacoscintigraphy to elucidate...

Using Pharmacoscintigraphy to Elucidate In Vivo Performance of Extended Release Formulations

David C. Sperry Research Advisor Small Molecule Design and Development

2nd FDA/PQRI Conference on Advancing Product Quality North Bethesda MD, 5-7 October 2015

Acknowledgements

♦ Eli Lilly • Ahmad Almaya • Mark Argentine • Evelyn Lobo

♦ Quotient Clinical • Alyson Connor • John McDermott • Lloyd Stevens

6 Oct 2015 © 2015 Eli Lilly and Company 2

In Vitro Methods for Extended Release Formulations ♦ In vitro methods generally have one goal in product

development:

→ Getting the “optimal” in vivo release rate

…then maintaining the desired performance over the life of the product.

♦ The “optimal” release rate may serve several purposes: – Blunting Cmax – Reduce dosing frequency – Matching absorption window – Tailoring PK profile


♦ In vivo release rate is difficult to measure ♦ Typical approach:

• use a surrogate in vitro method to develop dosage release rates • obtain human PK data on formulations • establish IVIVC or iterate until optimized

Getting the optimal in vivo release rate


IVIVC

In vitro

In v

ivo

Optimal

Alternate approach…

♦ Measure in vivo release more directly • Removes necessity for correlation to in vitro method • Can reduces PK study iterations

♦ Pharmacoscintigraphy


1. Dope formulation with radio-tracer element

2. In PK study, measure spatially resolved release of radio-tracer as a function of time.

3. Determine in vivo release as a function of time

LY545694 Tosylate

© 2015 Eli Lilly and Company 6

LY545694 Compound 645838

• LY545694 is a prodrug that is rapidly converted to Cmpd 645838

• Investigated for inflammatory and neuropathic pain

O

N N

Cl

N N

NO

OH

H

O

N N

Cl

N N

NOH

OH

H

6 Oct 2015

Need for extended release formulation ♦ Early studies used an

Immediate-Release formulation • Short half-life (2-7 hrs)

– BID dosing desired • Adverse GI and CNS events

– e.g., loss of appetite, nausea and vomiting, dizziness and headache

– Adverse events correlated with Cmax

♦ Extended Release formulations developed to decrease fluctuations and maintain active concentrations


Time (hr)

0 6 12 18 24 30 36 42 48 54 60 66 72D

ose

Nor

mal

ized

Mea

n C

ompo

und

6458

38

Plas

ma

Con

c (n

g/m

L/m

g)

0

2

4

6

8

0 3 6 9 12

0

2

4

6

8

Solution 33 mg, LQBBCapsule 73 mg, LQBBCR 14 mg, LQBE

6 Oct 2015

Initial ER formulation development


♦ Three ER formulations studied: • Fast (5-6 hrs), “A” • Intermediate (12-14 hrs), “B” • Slow (~24 hrs), “C”

♦ Deconvolution based on average data showed that cumulative input is truncated at ~6 hours

♦ Indication of an absorption window ♦ Significant portion of drug is not

absorbed

At 6 hrs, only ~70% of the dose is released

from Formulation B Fast Intermediate Slow

In vitro release Deconvoluted in vivo absorption

Objectives for LY545694 ER formulation ♦ Reduce Cmax to improve side effect profile ♦ Target release to the apparent absorption window ♦ Eliminate unabsorbed drug

• Theoretically, may improve safety profile • Also will reduce cost of product

(lower dose)

♦ Target: • Replicate the release profile of “Intermediate” through ~5 hours, in

terms of amount released.


Fast Intermediate Slow

In vitro release

Dissolution method – Preliminary IVIVC

♦ Media screen covering different pH and ionic strength.

♦ Relationship is useful for further formulation development.

♦ pH 2 method used going forward


Fast

0

20

40

60

80

100

0 2 4 6 8 10

Time, hour

% in

vitr

o re

leas

ed pH 2 HCl 0.01pH 2 HCl 0.2pH 2 Phos 0.01pH 2 Phos 0.2pH 6.8 BisTris 0.01pH 6.8 BisTris 0.2pH 6.8 Phos 0.01pH 6.8 Phos 0.2

Intermediate

0

20

40

60

80

100

0 5 10 15 20 25

Time, hour

% in

vitr

o re

leas

ed

pH 2 HCl 0.01pH 2 HCl 0.2pH 2 Phos 0.01pH 2 Phos 0.2pH 6.8 BisTris 0.01pH 6.8 BisTris 0.2pH 6.8 Phos 0.01pH 6.8 Phos 0.2

Slow

0

20

40

60

80

100

0 5 10 15 20 25

Time, hour

% in

vitr

o re

leas

ed

pH 2 HCl 0.01pH 2 HCl 0.2pH 2 Phos 0.01pH 2 Phos 0.2pH 6.8 BisTris 0.01pH 6.8 BisTris 0.2pH 6.8 Phos 0.01pH 6.8 Phos 0.2

Extened release formulation

♦ Formulations are hydrophilic matrix ♦ The drug substance is homogeneously mixed with the rate-controlling

excipient and other inactive ingredients. ♦ Indium-111 used as radiotracer


Prototypes Reference Methocel® K100LV Premium CR Methocel® K4M Premium CR LY545694 tosylate LY545694 tosylate

Lactose Lactose

Colloidal silicon dioxide Colloidal silicon dioxide

Microcrystalline cellulose Microcrystalline cellulose

Magnesium stearate Magnesium stearate 111In radiolabeled AMBERLITE IRP-69

6 Oct 2015

Methocel® K100LV Premium CR

20% w/w 25% w/w 30% w/w

Prototype 3 Prototype 2 Prototype 1

111In

IRP-69 – Cation exchange resin Prototypes Reference

Methocel® K100LV Premium CR Methocel® K4M Premium CR LY545694 tosylate LY545694 tosylate

Lactose Lactose

Colloidal silicon dioxide Colloidal silicon dioxide

Microcrystalline cellulose Microcrystalline cellulose

Magnesium stearate Magnesium stearate

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCOWd5u29zMcCFYayHgodv7cIdA&url=http://www.google.com/patents/US20130034503&ei=orLgVeXEBIbler_voqAH&psig=AFQjCNEx8T4OvwQw0BNeYnebVDVF4wWskg&ust=1440875537820114

Mechanism of release

1. Tablet hydrates and forms gel layer. 2. Gel layer erodes and release drug as the 3. water penetration front continues to

move into the dry core. 4. Eventually all of the drug is released

through an erosion mechanism.

→ The 111In carrying IRP-69 is released at the same rate as the drug.

→ Measuring In release is a surrogate for measuring drug release.


Resin effect on in vitro release


0

20

40

60

80

100

0 120 240 360 480 600 720 840 960 1080

% R

elea

sed

Time (min)

In Vitro Release ProfilesIllustrating Effect of Resin Binding

1243-09

1243-10

10 mg resin per tablet

5 mg resin per tablet w/o resin w/ resin

y = 0.9021x - 5.9566R² = 0.9983

y = xR² = 1

0.000

10.000

20.000

30.000

40.000

50.000

60.000

0.000 10.000 20.000 30.000 40.000 50.000 60.000

Free

Dru

g Co

ncen

tratio

n (u

g/m

L)

Total Drug Concentration (ug/mL)

Spiked Concentration vs. Measured Concentration

Actual Interaction

No Interaction

Linear (Actual Interaction)

Linear (No Interaction)

Resin binding effect.

Theoretical recovery with no binding.

Actual recovery.

O

N N

Cl

N N

NO

OH

H

0

20

40

60

80

100

0 120 240 360 480 600 720 840 960 1080

% R

elea

sed

Time (min)

In Vitro Release ProfilesIllustrating Effect of Resin Binding

1243-01

1243-03

• AMBERLITE IRP-69 is a strong acid ion exchange resin

• LY545694 is cationic binds to resin

Scintigraphy – Surrogate for in vivo drug release


0

20

40

60

80

100

0 5 10 15 20

% R

elea

sed

Time (hours)

In Vitro Drug Release and Radioactivity Release

Formulation XFormulation XFormulation YFormulation YReferenceReference

Lines - Drug ReleaseSymbols - Radioactivity

♦ Measure in vitro drug release and radioactivity release simultaneously.

♦ Agreement is good.

♦ Radioactivity release is good surrogate for in vivo drug release

♦ Also supports erosion-based-release hypothesis

PK study design

♦ 6 formulations • Solution - unlabeled • ER reference – unlabeled • ER reference – labeled • Prototype 1 – labeled • Prototype 2 – labeled • Prototype 3 – labeled

♦ 16 males, 18-65 years ♦ Open-label, fixed treatment sequence, 6-period,single

dose, crossover study design conducted at a single center

♦ 7 day washout between doses


Controlled release formulations: In vitro versus in vivo LY545694

16

Time (hr)

0 6 12 18 24

Mea

n LY

5456

94 C

onc

(ng/

mL)

0

20

40

60

80

Time (hr)

0 2 4 6 8 10 12 14 16 18

Frac

tion

LY54

5694

Dis

solv

ed

0.0

0.2

0.4

0.6

0.8

1.0

Prototype 1 (25 mg) Labeled Reference (35 mg)Prototype 2 (25 mg)Prototype 3 (25 mg)Unlabeled Reference (35 mg)

6 Oct 2015 © 2015 Eli Lilly and Company

Prototype 3 gives same PK profile at lower dose.

Methocel® K100LV Premium CR

20% w/w 25% w/w 30% w/w

Prototype 3 Prototype 2 Prototype 1

Pharmacoscintigraphy of LY545694 ER tablets


♦ PK plasma data alone may not explain the dosage form performance in the GI tract.

♦ Tracking the location and rate of erosion of ER tablets in the GI tract will complement PK data.

♦ Images at 10-minute intervals until 8 hours postdose, and then every 30 minutes until 12 hours postdose.

♦ Can measure GI transit times and GI location of the dosage form.

Initial tablet erosion

♦ The time to detect any sign of release of radioactive marker from the tablet


Trail of radioactivity observed

Spatial marker

Complete tablet erosion

♦The time at which all the radiolabelled marker has dispersed in the gastrointestinal tract and no signs of a “distinct” core remain.


Tablet core clearly visible Radioactivity dispersed

Pharmacokinetic results


Radiolabeled Reference (35 mg) Prototype 1 (25 mg)

Time (h)

0 12 24 36 48

Mea

n Pl

asm

a L

Y54

5694

Con

cent

ratio

n (n

g/m

L)

0

10

20

30

40

50

60

70

Time (hr)

0 2 4 6 8 10 12 14 16

Frac

tion

Abso

rbed

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Time (hr)

0 2 4 6 8 10 12 14 16 18

Frac

tion

LY54

5694

Dis

solv

ed

0.0

0.2

0.4

0.6

0.8

1.0

In Vitro performance NOT predictive of In Vivo performance, in this case.

♦ Scintigraphy shows that in vivo erosion rate is not what was predicted by in vitro test. C

ompl

ete

Eros

ion

Tim

e (h

ours

pos

t dos

e)

0

1

2

3

4

5

6

7

8

9

10

11

CR Reference Prototype 1

Formulation

Hypothesized absorption window

0

1

2

3

4

5

6

7

S PSB DSB AC HF TC SF DC

Location of Complete ErosionCR Reference

Location of complete erosion CR reference*

N=5

N=4

N=1

N=1

N=2

N=2

N=1

* S/PSB have been presented as PSB; DSB/AC have been presented as AC

Gastrointestinal transit

21 © 2015 Eli Lilly and Company 6 Oct 2015

Location of complete erosion Prototype 1

* S/PSB have been presented as PSB; DSB/AC have been presented as AC

N=0

N=7

N=0

N=1

N=3

N=4

N=1

0

1

2

3

4

5

6

7


Location of Complete ErosionPrototype 1




Location of complete erosion Prototype 2*

* S/PSB presented as PSB; DSB/AC presented as AC; AC/HF presented as HF

N=6

N=0

N=0

N=1

N=5

N=1

N=2

0

1

2

3

4

5

6

7






Location of complete erosion Prototype 3*

* S/PSB presented as PSB; DSB/AC presented as AC; AC/HF presented as HF

N=6

N=2

N=0

N=0

N=1

N=5

N=1

0

1

2

3

4

5

6

7






Complete erosion time


Com

plet

e Er

osio

n Ti

me

(hou

rs p

ost d

ose)

0

1

2

3

4

5

6

7

8

9

10

11

CR Reference Prototype 1 Prototype 2 Prototype 3

Formulation

Time (hr)

0 2 4 6 8 10 12 14 16 18

Frac

tion

LY54

5694

Dis

solv

ed

0.0

0.2

0.4

0.6

0.8

1.0

• Complete erosion times consistent with PK…

Time (hr)

0 6 12 18 24

Mea

n LY

5456

94 C

onc

(ng/

mL)

0

20

40

60

80

but not with in vitro data.

Quantitative erosion profiles


“In-tact” tablet area is defined

Radioactivity inside defined area is integrated as a fraction of total radioactivity in image.

(illustration only, not actual analysis)

0.00

20.00

40.00

60.00

80.00

100.00

0.00 2.00 4.00 6.00 8.00

% o

f Tab

ler

Erod

ed

Time (hours)

In Vivo Erosion - Subject 15

Prototype 1

6 Oct 2015

Time (h)

0 2 4 6 8

Frac

tion

Abso

rbed

(TO

TAL)

0.0

0.2

0.4

0.6

0.8

1.0

Prototype 1Radiolabelled ReferencePrototype 2Prototype 3Unlabelled Reference

In vivo erosion profiles - PK


Time (hr)

0 3 6 9 12

Mea

n LY

5456

94 C

onc

(ng/

mL)

0

20

40

60

80♦ Individual erosion compiled into average erosion

♦ In vivo erosion and PK data agree quite well

0

10

20

30

40

50

60

70

80

90

100

110

0 2 4 6 8 10 12

% o

f Tab

let

Erod

ed

Time (hours)

Average In Vivo Erosion Profiles

CR Reference

Prototype 1

Prototype 2

Prototype 3

In Vivo Erosion Profiles – In Vitro Release


Time (hr)

0 2 4 6 8 10 12 14 16 18

Frac

tion

LY54

5694

Dis

solv

ed

0.0

0.2

0.4

0.6

0.8

1.0In Vitro Release - CT Lots

6 Oct 2015

♦ In vivo erosion shows that in vitro test was not predictive across reference and prototype formulation types

♦ In vitro test was predictive within prototype space

0

10

20

30

40

50

60

70

80

90

100

110

0 2 4 6 8 10 12

% o

f Tab

let

Erod

ed

Time (hours)

Average In Vivo Erosion Profiles

CR Reference

Prototype 1

Prototype 2

Prototype 3

Summary

♦ Outcome: reduced dose ~20% with comparable PK profile • Release rate of selected prototype matches in vivo absorption window • Reduce the risk of inter-patient variability in amount absorbed • Potential improved patient safety • Study costs would have been fully recouped in Phase III API cost

reduction ♦ Pharmacoscintigraphy can improve understanding of in vivo

behavior of ER formulations. • Reduce iterative nature of formulation design • Scintigraphy results can help explain PK results • Care must be taken to ensure that radiolabeling does not interfere with

drug release


Acknowledgements


♦ Formulation development and manufacturing • Nick McEntee • Abigail Pedigo • Chad Martinsen • Claudia Jacobs

♦ Analytical in vitro dissolution • Matthew Deverall

♦ Clinical analytical support • Robert Stratford

♦ Support on the clinical study • Shobha Reddy • Chris Payne • Harry Haber (i3 Statprobe,

Inc., Ann Arbor MI) • Matt Dunn

♦ Quality oversight • Matthew Curley • Gaetan Rygaert • Stacy Nolan

♦ Pre-formulation modeling support. • Xuan Ding

BACKUP SLIDES

Mean concentration profiles

32

Time (hr)

0 3 6 9 12

Mea

n LY

5456

94 C

onc

(ng/

mL)

0

20

40

60

80

Time (hr)

0 3 6 9 12

Mea

n C

ompo

und

6458

38 C

onc

(ng/

mL)

0

20

40

60

80

Prototype 1 (25 mg)Prototype 2 (25 mg)Prototype 3 (25 mg)

Unlabeled Reference (35 mg)

6 Oct 2015 © 2015 Eli Lilly and Company

Prototype 3 gives same PK profile at lower dose.

LY545694 Active metabolite

using pharmacoscintigraphy to elucidate in vivo ...€¦ · using pharmacoscintigraphy to elucidate...

Documents