Device and method for determining reaction kinetics

Patent metadata

Field	Value
Publication number	US-9632095-B2
Application number	US-201514942117-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Dec 1, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A method of determining the activation energy E a for degradation of a chemical species includes in sequence the steps of a) simultaneously incubating a plurality of samples of the chemical species in a single unitary device at a plurality of constant temperatures T, in each case for an incubation time t selected to result in loss of at most 20 mol % of the amount originally present; b) quenching each of the samples to stop degradation; c) determining the mole fraction m of the chemical species remaining in each of the quenched samples, relative to the amount present before incubating; d) determining for each sample a reaction rate coefficient k obs according to the equation
k obs ⁡ ( T ) = 1 - m ⁡ ( T ) t ;
and e) performing numerical regression of the k obs values obtained in step d) and the corresponding temperatures T in ° K to derive the activation energy E a according to the following equation

k obs = k 0 ⁢ exp ⁡ ( E a R ⁢ ( 1 T - 1 T 0 ) ) ,
or to derive a temperature-dependent activation energy if that is more appropriate for the chemical species of interest.

First claim

What is claimed is:

1. A method of determining the reaction rate coefficient (k obs ) for the degradation of a chemical species at each of a plurality of constant temperatures, comprising in sequence the steps of
a) simultaneously incubating a plurality of samples of the chemical species in a single unitary device at said plurality of constant temperatures T, wherein the incubation of each of the plurality of samples is performed for an incubation time t selected to result in loss of a portion of the chemical species, said portion being at most 20 mol % of the amount originally present, where the choice of t might or might not be the same for each value of T;
b) quenching each of the samples in a manner sufficient to stop degradation;
c) determining the mole fraction m of the chemical species remaining in each of the quenched samples, relative to the amount present before incubating; and
d) determining for each sample a reaction rate coefficient k obs according to the equation

k
obs

⁡

(
T
)

=

1
-

m
⁡

(
T
)

t

.

2. The method of claim 1 , wherein the chemical species is a pharmaceutical product.

3. The method of claim 1 , wherein the chemical species is a protein.

4. The method of claim 3 , wherein the degradation comprises aggregation.

5. The method of claim 3 , wherein the degradation comprises non-native aggregation.

6. The method of claim 3 , wherein the degradation comprises chemical degradation.

7. The method of claim 1 , wherein the loss of the chemical species is at most 10 mol %.

8. The method of claim 1 , further comprising e) performing numerical regression of the k obs values obtained in step d) and the corresponding temperatures T in ° K to derive the activation energy E a of the degradation of the chemical species according to the following equation

k
obs

=

k
0

⁢

exp
⁡

(

E
a

R

⁢

(

1
T

-

1

T
0

)

)

wherein k 0 is the value of k obs for T 0 , one of the plurality of temperatures in ° K.

9. The method of claim 8 , wherein the chemical species is a pharmaceutical product.

10. The method of claim 8 , wherein the chemical species is a protein.

11. The method of claim 10 , wherein the degradation comprises aggregation.

12. The method of claim 10 , wherein the degradation comprises non-native aggregation.

13. The method of claim 10 , wherein the degradation comprises chemical degradation.

14. The method of claim 8 , wherein the loss of the chemical species is at most 10 mol %.

Assignees

• Univ Delaware
• Amgen Inc

Inventors

• Roberts Christopher J
• Barnett Gregory V
• Razinkov Vladimir I
• Kerwin Bruce A

Classifications

• G01N33/6845 Primary

  Methods of identifying protein-protein interactions in protein mixtures · CPC title

• G01N33/50

  Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing (measuring or testing processes involving enzymes or microorganisms, compositions or test papers therefor; processes for forming such compositions, condition responsive control in microbiological or enzymological processes C12Q) · CPC title