The purpose of this study is to determine whether TZP-101 is safe in people with diabetes. Also to determine if TZP-101 is effective in increasing the gastric emptying rate in diabetic patients.

Inclusion Criteria:

• Subject has type 1 or type 2 diabetes mellitus
• Subject has documented diagnosis of gastroparesis by:
• Delayed gastric emptying (gastric retention ≥60% at 2h and ≥10% at 4 h; based on scintigraphy -4h standardized radionuclide solid meal)
• A minimum 3 month history of chronic upper abdominal discomfort (two or more: chronic postprandial fullness, bloating, epigastric discomfort, early satiety, belching after meal, postprandial nausea, vomiting)
• Subject has normal upper endoscopy
• If female, must be permanently sterilized or postmenopausa.

Exclusion Criteria:

• Patient has received any investigational drug within the preceding 30 days
• Patient is taking unstable doses of medication that affects gastric motility
• Patient has co-morbid condition
• Patient has a positive laboratory test result for hepatitis B, hepatitis C, HIV, or controlled substances.
• Patient has a history of a psychiatric disorder (including drug or alcohol addiction) requiring care by a psychiatrist or psychologist within the preceding 12 months.
• Patient has a recent,adult history of clinically significanthypersensitivity reaction(s) to any drug.
• Patient has known history of alcoholism