applying microcalorimetry to characterize the stability ... microcalorimetry to characterize...

Applying Microcalorimetry to Characterize the Stability Applying Microcalorimetry to Characterize the Stability and Compatibility of Pharmaceutical Systemsand Compatibility of Pharmaceutical Systems

Time/s0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000

HeatFlow/mW

-0.35

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

0.15

-0.35

-0.30

-0.25

-0.20

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0.00

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0.15

Figure:25/11/2002 Mass (mg):674.8

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: 35 37.5 40 42.5 45 3 hours each (Zone 2)Micro DSC III

Exo Exo

Exo

35C 37.5C 40C 42.5C 45C

ThermalCal International

http://www.thermalcal.com/

http://www.thermalcal.com/

OutlineOutlineMicrocalorimetry: The Universal Detector

Overview of Microcalorimetry Stability and Compatibility Testing

Overview of Commercially Available Microcalorimeters

∆G = ∆ H - T ∆ S

Microcalorimetry: The Universal DetectorMicrocalorimetry: The Universal DetectorIsothermal Microcalorimetry

Heat Flow Measured as Difference Between Sample and Reference

Isothermal Temperature Usually Maintained by Large Volume Constant Temperature Bath

Typical Detection Limit ~ +/-0.5 uJ/sec

Sample Sizes Range from 1ml to 150ml

Temperature Range ~ 5 to 90 °C

dQ/dt = ∆H *dn/dt

∆G = ∆ H - T ∆ S


Chemical ProcessesHydrolysis, oxidation, free radical, etc. all have large

heats of reaction.

Ideally, degradation rates of less than 1% per year can be predicted in a matter of days.

Physical and Bio ProcessesCrystallization, polymorph conversions, bacterial

growth.

∆G = ∆ H - T ∆ S


Closed or Open Systems

Batch BatchMixing Pressure

FluidMixingFluid

∆G = ∆ H - T ∆ S


Qox = ∆ Hox*nox

Qhyd = ∆ Hhyd*nhyd

etc.

etc.

Qmeasured = Σi∆ Hi*ni

Standard Addition

∆G = ∆ H - T ∆ S

Microcalorimetry: The Universal DetectorMicrocalorimetry: The Universal DetectorScanning Microcalorimetry (HSDSC)

Heat Flow Measured as Difference Between Sample and Reference

Temperature Ramped by Peltier Elements or Fluid Circulation. Heat/Cool. Isothermal.

Typical Detection Limit ~.2-5 uJ/sec

Sample Sizes Range from .3 ml to 1 ml

Slow Scan Rates .001 – 1 °C /min

Temperature Range ~ -45 to 120 °C

d(dQ/dt)/dT = ∆H *d(dn/dt)/dT

∆G = ∆ H - T ∆ S


Chemical ProcessesThermally induced chemical reactions.

Physical and Bio ProcessesGlass transitions, thermally induced crystallization and polymorph conversions, protein denaturation.

∆G = ∆ H - T ∆ S


Closed or Open Systems

BatchMixing

Batch

Wetting

Fluid FluidMixing∆G = ∆ H - T ∆ S

Microcalorimetry: The Universal DetectorMicrocalorimetry: The Universal DetectorDetection LimitsDetection Limits

•If a significant signal of 1 µW is detectable, and if it is assumed that the reaction enthalpy ∆HR, is 50 kJ/mole for the compound, it is possible to estimate the rate of reaction x :•x = (10-6 J/s / 50x103 J/mole) = 2x10-11 mole/sec,

or 1.2x10-9 mole/min, or 1.7x10-6 mole/day, or 6.3x10-4 mole/year

•It is also possible to use the Arrhenius law for different temperatures : dα/dt = k (1- α)n = k0 exp(-E/RT) (1- α)n

•dα/dt is proportional to the calorimetric signal (dH/dt)•Plotting Log(dH/dt) versus 1/T yields the kinetic parameters of the reaction.

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingReaction in Solution: pH EffectReaction in Solution: pH Effect

Furnace temperature /°C30 35 40 45 50 55 60 65 70 75 80

-0.30

-0.25

-0.20

-0.15

-0.10

-0.05

0.00

0.05

0.10

pH 4

pH 6

pH 8

pH 10

Figure:Mass (mg):15.43

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: scan 10C to 95C (Zone 7)

Exo

Exo Exo

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingReaction in Solution: pH EffectReaction in Solution: pH Effect

2.75 2.80 2.85 2.90 2.95 3.00 3.05 3.106.2

6.4

6.6

6.8

7.0

7.2

7.4

7.6

7.8

Linear Regression for ph8_B:Y = A + B * X

Parameter Value Error------------------------------------------------------------A 19.9813 0.44947B -4.41783 0.1539------------------------------------------------------------

R SD N P-------------------------------------------------------------0.98056 0.08826 35 <0.0001------------------------------------------------------------

ln(u

W/g

)

1/T(K)*10002.7 2.8 2.9 3.0 3.1 3.2

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

Linear Regression for ph10scan_B:Y = A + B * X


R SD N P-------------------------------------------------------------0.99982 0.00817 28 <0.0001------------------------------------------------------------

Linear Regression for ph10scan_B:Y = A + B * X


R SD N P-------------------------------------------------------------0.99565 0.02975 9 <0.0001------------------------------------------------------------

ln(u

W/g

)

1/T(K)*1000

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingReaction in Solution: Solvent EffectReaction in Solution: Solvent Effect

Hydrolysis of Ester with NaOH at 25C

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

0 200 400 600 800 1000 1200time (sec)

Q/Q

tot

0% DMF4.8% DMF17% DMF

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingAPI Stability in PEG: Effect of BHTAPI Stability in PEG: Effect of BHT

Time/s0 5000 10000 15000 20000 25000 30000 35000 40000 45000 50000

0.0 0.0

35C 37.5C 40C 42.5C 45C

Red: API/PEG (no BHT) - Placebo

Blue: API/PEG (with BHT) - Placebo

Figure:29/10/2002 Mass (mg):715.8

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: 35 37.5 40 42.5 45 3 hours each (Zone 2)

ExoExo

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingSolution Stability: Impact of PreservativeSolution Stability: Impact of Preservative

Effect of Preservative on Bacteria Growth

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30 35 40

Time (hours)

Ther

mal A

ctivit

y (uJ

oules

/sec)

Biological Solution

Biological Solution + Propyl Gallate

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingSolid State Stability: RealSolid State Stability: Real--time Monitoring of Polymorph Conversiontime Monitoring of Polymorph Conversion

Time/h2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5

-0.4

-0.2

-0.0

0.2

0.4

HeatFlow/mW

-0.4

-0.2

-0.0

0.2

0.4Blue:Sample= .5g aluminaReference= steel cell

Black:Sample= 472.9 mg form 1Reference= steel cell

Red:Sample= 460.0 mg form I Reference= steel cell

Thermal Activity

60C 70C 80C

89C

Figure: 22/10/2002 Mass (mg):472.9

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure:

ExoExo

Blank

Thermal disturbances caused by temperature

ramping

Time/h2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5

HeatFlow/mW

-0.4

-0.2

-0.0

0.2

0.4

-0.4

-0.2

-0.0

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0.4

Blue:Sample= .5g aluminaReference= steel cell

Red:Sample= 352.7mg form II Reference= steel cell

Black:Sample= 410.6 mg Reference= steel cell

80C 60C 70C 89C

Thermal Activity

Figure: 23/10/2002

Crucible: Standard HastelloyAtmosphere:AirExperimentation: Procedure:

Exo Exo

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingSolid State Stability: RealSolid State Stability: Real--time Monitoring of Polymorph Conversiontime Monitoring of Polymorph Conversion

Time/h2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5

-0.4

-0.2

-0.0

0.2

0.4

HeatFlow/mW

-0.4

-0.2

-0.0

0.2

0.4Blue:Sample= .5g aluminaReference= steel cell

Black:Sample= 472.9 mg form 1Reference= steel cell

Red:Sample= 460.0 mg form I Reference= steel cell

Thermal Activity

60C 70C 80C

89C

Figure: 22/10/2002 Mass (mg):472.9

Crucible: Standard HastelloyAtmosphere:AirExperimentation: Procedure:

ExoExo

Blank

Time/h2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5

Heat Flow - 2 - red3 970011 isotherms at 50,60,70,80,89/mW

-0.4

-0.2

-0.0

0.2

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0.4Blue:Sample= .5g aluminaReference= steel cellBlack:Sample= 338.5 mg mixedReference= steel cellRed:Sample= 520.2 mg mixed Reference= steel cell

Thermal Activity

Figure: 24/10/2002 Mass (mg):409.4


Exo

338.5mg

520.2mg

Blank

60C 70C80C

89C

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingProtein Stability: Impact of StabilizerProtein Stability: Impact of Stabilizer

Furnace temperature /°C30 35 40 45 50 55 60 65 70 75 80

HeatFlow/mW

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8 Peak 1 :66.6557 °CPeak 2 :70.9494 °COnset Point :61.7528 °C Enthalpy /J : 0.0378 (Endothermic effect) (0.0562 + -0.0185)

Peak 1 :67.2049 °C Peak 2 :73.3009 °C Onset Point :62.2572 °C Enthalpy /J : 0.0331 (Endothermic effect) (0.0549 + -0.0217)

1 % BSA

1% BSA + 4% Manitol

Figure:17/06/2002 Mass (mg):0

Crucible: batch Atmosphere:AirExperimentation:1% BSA Procedure: BSA scan 22 to 90 (Zone 2)

Exo

Exo

∆G = ∆ H - T ∆ S

Microcalorimetry: Stability TestingMicrocalorimetry: Stability TestingSolid State Stability: Influence of HumiditySolid State Stability: Influence of Humidity

Time/h0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

HeatFlow/mW

0.0

0.5

1.0

1.5

0.0

0.5

1.0

1.5

Red: Lot AGreen: Lot BBlue: Lot C1.4 hr

4.7 hr

2.4 hr

Figure:14/01/2003 Mass (mg):599.6


Exo

Exo

Exo

∆G = ∆ H - T ∆ S

Microcalorimetry: Compatibility TestingMicrocalorimetry: Compatibility TestingGeneral ConceptGeneral Concept

+Time ---> TA of API q1

+Time ---> TA of Excipient q2

+Time ---> TA of Mix qmix

qmix = x1q1 + x2q2 ?

∆G = ∆ H - T ∆ S

Microcalorimetry: Compatibility TestingMicrocalorimetry: Compatibility TestingHSDSCHSDSC

Furnace temperature /°C20 40 60 80 100

HeatFlow/mW

-16

-14

-12

-10

-8

-6

-4

-2

-16

-14

-12

-10

-8

-6

-4

-2

114 C

Red: Placebo

Blue: API

Black: Formulation

Figure:01/03/2003 Mass (mg):500.2

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: scan 15C to 119C (Zone 4)

Exo Exo

Exo Exo

∆G = ∆ H - T ∆ S

Microcalorimetry: Compatibility TestingMicrocalorimetry: Compatibility TestingHSDSCHSDSC

Furnace temperature /°C30 40 50 60 70 80 90

-16

-14

-12

-10

-8

-6

-4

-2

0

-0.8

-0.6

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0.4

Formulation

Amorphous

Figure:15/01/2003 Mass (mg):26.2

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: scan 15-119 (Zone 7)

ExoExo

∆G = ∆ H - T ∆ S

Microcalorimetry: Compatibility TestingMicrocalorimetry: Compatibility TestingIsothermal Thermal ActivityIsothermal Thermal Activity

Time/h0 2 4 6 8 10 12 14 16 18

HeatFlow/mW

-0.5

-0.4

-0.3

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-0.0

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-0.0

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0.4

Red: placeboBlue: Salt Form ABlack: Salt Form B

Figure:12/11/2002 Mass (mg):599.4

Crucible: Standard HastelloyAtmosphere:AirExperimentation:Procedure: 50 60 70 3 hours each (Zone 2)

Exo Exo

Exo Exo

∆G = ∆ H - T ∆ S

applying microcalorimetry to characterize the stability ... microcalorimetry to characterize...

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