Crystals and process of making 5-({(2-amino-3-(4-carbamoyl-2,6-dimethyl-phenyl)-propionyl]-[1-(-4-phenyl-1h-imidazol-2-yl)-ethyl]-amino}-methyl)-2-methoxy-benzoic acid

1. Form α crystal of 5-({[2-amino-3-(4-carbamoyl-2,6-dimethyl-phenyl)-propionyl]-[1-(4-phenyl-1h-imidazol-2-yl)-ethyl]-amino}-methyl)-2-methoxy-benzoic acid.

2. The α crystal of claim 1 , wherein said crystal is characterized by a powder X-ray diffraction pattern having powder X-ray diffraction peaks at about 14.0, 14.3, and 14.7 degrees 2-theta.

3. The α crystal of claim 1 , wherein said crystal is characterized by a powder X-ray diffraction pattern having powder X-ray diffraction peaks at about 10.2, 11.3, 14.0, 14.3, and 14.7 degrees 2-theta.

4. The α crystal of claim 1 , wherein said crystal is characterized by a powder X-ray diffraction pattern having powder X-ray diffraction peaks at about 10.2, 11.3, 11.8, 14.0, 14.3, 14.7, 16.1, and 18.3 degrees 2-theta.

5. The α crystal of claim 1 , wherein said crystal is characterized by a powder X-ray diffraction pattern having powder X-ray diffraction peaks substantially as shown in Table 1.

6. The α crystal of claim 1 , wherein said crystal is characterized by a powder X-ray diffraction pattern having powder X-ray diffraction peaks substantially similar to the powder X-ray diffraction peaks of FIG. 1 .

7. The α crystal of claim 1 , wherein said crystal is characterized by a thermal gravimetric analysis (TGA) substantially similar to the TGA in FIG. 2 .

8. The α crystal of claim 1 , wherein said crystal is characterized by a differential scanning calorimetry (DSC) measurement substantially similar to the DSC in FIG. 3 .

9. A method of treating a mammal suffering from irritable bowel syndrome, pain or another opioid receptor disorder comprising administering to said mammal an effective amount of a Form α crystal of 5-({[2-amino-3-(4-carbamoyl-2,6-dimethyl-phenyl)-propionyl]-[1-(4-phenyl-1h-imidazol-2-yl)-ethyl]-amino}-methyl)-2-methoxy-benzoic acid.