| abstract |
A compound having Formula I: ** Formula ** or a pharmaceutically acceptable salt thereof, in which: each of R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 is independently selected of hydrogen and deuterium, in which at least one of R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 is not hydrogen, and in which when each of R1, R2, R9 and R10 is hydrogen, at least one of R3, R4, R5, R6, R7 and R8 is different from deuterium, and in which a position that is designated as "D" or deuterium, it is understood that the position has deuterium with a abundance that is at least 3,340 times greater than the natural abundance of deuterium. |