DEUTERIUM-ENRICHED OXYBUTYNIN

1 . A method for treating overactive bladder comprising: administering, to a patient in need thereof, a therapeutically effective amount of a deuterium-enriched compound of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 31 are independently selected from H and D; and the abundance of deuterium in R 1 -R 31 is at least 3% provided that the compound is other than:

(a) a compound where each of R 22 -R 31 is D or

(b) a compound where each of R 20 -R 21 is D.

2 . The method of claim 1 , wherein the abundance of deuterium in R 1 -R 31 is selected from at least 3%, at least 6%, at least 13%, at least 19%, at least 26%, at least 32%, at least 39%, at least 45%, at least 52%, at least 58%, at least 65%, at least 71%, at least 77%, at least 84%, at least 90%, at least 97%, and 100%.

3 . The method of claim 1 , wherein the abundance of deuterium in R 1 is 100%.

4 . The method of claim 1 , wherein the abundance of deuterium in R 1 , R 20 -R 21 , and R 22 -R 31 is selected from at least 8%, at least 15%, at least 23%, at least 31%, at least 38%, at least 46%, at least 54%, at least 62%, at least 69%, at least 77%, at least 85%, at least 92%, and 100%.

5 . The method of claim 1 , wherein the abundance of deuterium in R 20 -R 21 and R 22 -R 31 is selected from at least 8%, at least 17%, at least 25%, at least 33%, at least 42%, at least 50%, at least 58%, at least 67%, at least 75%, at least 83%, at least 92%, and 100%.

6 . The method of claim 1 , wherein the abundance of deuterium in R 2 -R 6 is selected from at least 20%, at least 40%, at least 60%, at least 80%, and 100%.

7 . The method of claim 1 , wherein the abundance of deuterium in R 7 -R 17 is selected from at least 9%, at least 18%, at least 27%, at least 36%, at least 45%, at least 56%, at least 64%, at least 73%, at least 82%, at least 91%, and 100%.

8 . The method of claim 1 , wherein the compound is selected from compounds 1-8 of Table 1:

9 . The method of claim 1 , wherein the compound is selected from compounds 9-16 of Table 2:

10 . A method for treating overactive bladder comprising: administering, to a patient in need thereof, a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 31 are independently selected from H and D; and the abundance of deuterium in R 1 -R 31 is at least 3% provided that the compound is other than:

(a) a compound where each of R 22 -R 31 is D or

(b) a compound where each of R 20 -R 21 is D.

11 . The method of claim 10 , wherein the abundance of deuterium in R 1 -R 31 is selected from at least 3%, at least 6%, at least 13%, at least 19%, at least 26%, at least 32%, at least 39%, at least 45%, at least 52%, at least 58%, at least 65%, at least 71%, at least 77%, at least 84%, at least 90%, at least 97%, and 100%.

12 . The method of claim 10 , wherein the abundance of deuterium in R 1 is 100%.

13 . The method claim 10 , wherein the abundance of deuterium in R 1 , R 20 -R 21 , and R 22 -R 31 is selected from at least 8%, at least 15%, at least 23%, at least 31%, at least 38%, at least 46%, at least 54%, at least 62%, at least 69%, at least 77%, at least 85%, at least 92%, and 100%.

14 . The method of claim 10 , wherein the abundance of deuterium in R 20 -R 21 and R 22 -R 31 is selected from at least 8%, at least 17%, at least 25%, at least 33%, at least 42%, at least 50%, at least 58%, at least 67%, at least 75%, at least 83%, at least 92%, and 100%.

15 . The method of claim 10 , wherein the abundance of deuterium in R 2 -R 6 is selected from at least 20%, at least 40%, at least 60%, at least 80%, and 100%.

16 . The method of claim 10 , wherein the abundance of deuterium in R 7 -R 17 is selected from at least 9%, at least 18%, at least 27%, at least 36%, at least 45%, at least 56%, at least 64%, at least 73%, at least 82%, at least 91%, and 100%.

17 . The method of claim 10 , wherein the compound is selected from compounds 1-8 of Table 1:

18 . The method of claim 10 , wherein the compound is selected from compounds 9-16 of Table 2:

19 . A method for treating overactive bladder comprising: administering, to a patient in need thereof, a therapeutically effective amount of a mixture of deuterium-enriched compounds of formula I or a pharmaceutically acceptable salt thereof:

wherein R 1 -R 31 are independently selected from H and D; and the abundance of deuterium in R 1 -R 31 is at least 3% provided that the compound is other than:

(a) a compound where each of R 22 -R 31 is D or

(b) a compound where each of R 20 -R 21 is D.

20 . The method of claim 19 , wherein the abundance of deuterium in R 1 -R 31 is selected from at least 3%, at least 6%, at least 13%, at least 19%, at least 26%, at least 32%, at least 39%, at least 45%, at least 52%, at least 58%, at least 65%, at least 71%, at least 77%, at least 84%, at least 90%, at least 97%, and 100%.

21 . The method of claim 19 , wherein the abundance of deuterium in R 1 is 100%.

22 . The method of claim 19 , wherein the abundance of deuterium in R 1 , R 20 -R 21 , and R 22 -R 31 is selected from at least 8%, at least 15%, at least 23%, at least 31%, at least 38%, at least 46%, at least 54%, at least 62%, at least 69%, at least 77%, at least 85%, at least 92%, and 100%.

23 . The method of claim 19 , wherein the abundance of deuterium in R 20 -R 21 and R 22 -R 31 is selected from at least 8%, at least 17%, at least 25%, at least 33%, at least 42%, at least 50%, at least 58%, at least 67%, at least 75%, at least 83%, at least 92%, and 100%.

24 . The method of claim 19 , wherein the abundance of deuterium in R 2 -R 6 is selected from at least 20%, at least 40%, at least 60%, at least 80%, and 100%.

25 . The method of claim 19 , wherein the abundance of deuterium in R 7 -R 17 is selected from at least 9%, at least 18%, at least 27%, at least 36%, at least 45%, at least 56%, at least 64%, at least 73%, at least 82%, at least 91%, and 100%.

26 . The method of claim 19 , wherein the compounds are selected from compounds I-8 of Table 1:

27 . The method of claim 19 , wherein the compounds are selected from compounds 9-16 of Table 2: