Compounds, methods and formulations for the oral delivery of a glucagon-like peptide (GLP-1) compound or a melanocortin-4 receptor (MC4) agonist peptide

1. A compound of formula (I), or a pharmaceutically acceptable salt thereof:

wherein

R 1 is NH 2 ;

R 2 is H;

R 3 is H;

n is 2, 3, 4 or 5; and

X is

 where the phenyl substituent is attached at carbon atom number 4 and the alkanoic acid chain is attached at carbon atom number 2.

2. The compound according to claim 1 , selected from

and pharmaceutically acceptable salts thereof.

3. A compound according to claim 2 , which is:

or a pharmaceutical salt thereof.

4. A compound according to claim 2 , which is:

or a pharmaceutical salt thereof.

5. A compound according to claim 2 , which is:

or a pharmaceutical salt thereof.

6. A compound according to claim 2 , which is:

or a pharmaceutical salt thereof.

7. A pharmaceutical composition comprising:

a) a compound according to claim 1 , or a pharmaceutical salt thereof; and

b) a GLP-1 compound.

8. The pharmaceutical composition according to claim 7 , wherein the GLP-1 compound is a GLP-1 derivative.

9. The pharmaceutical composition according to claim 7 , wherein the GLP-1 compound is a GLP-1 analog.

10. The composition according claim 7 , wherein the GLP-1 compound is Val 8 -Glu 22 -GLP-1(7-37)OH.

11. A pharmaceutical composition comprising:

a) a compound of claim 1 or a pharmaceutical salt thereof; and

b) an MC4 agonist peptide.

12. The composition of claim 11 , wherein the MC4 agonist peptide is selected from the group consisting of:

Ac-Arg-cyclo[Cys-Glu-His-D-Phe-Arg-Trp-Cys]-NH 2 ;

Ac-cyclo[hCys-His-D-Phe-Arg-Trp-Cys]-NH 2 ;

Ac-cyclo [hCys-His-D-Phe-Arg-Trp-penicillamine]-NH 2 ; and

N-cyclohexanecarbonyl-cyclo[hCys-His-D-Phe-Arg-Trp-penicillamine]-NH 2 .