Affects of Once-daily Oral Administration of TZP-102 on the Treatment of Symptoms Associated With Diabetic Gastroparesis

Inclusion Criteria: * 18 to 80 years of age, inclusive * Type 1 or type 2 diabetes mellitus * History of symptoms of gastroparesis for at least 3 months leading up to the Screening Visit * Gastric half-emptying time \>82 minutes, demonstrated by the Gastric Emptying Breath Test performed at the Screening Visit OR documented delayed gastric emptying within the previous 24 months * Mild to moderate severity of gastroparesis symptoms during the screening period * Body Mass Index (BMI) \< 45.0 at the Screening Visit * Glycosylated hemoglobin (HbA1c) level \< 11.0% at the Screening Visit * Upper gastrointestinal obstruction ruled out by endoscopy or barium scan * Concomitant medications must be stable for at least 2 weeks leading up to the Baseline Visit and must be maintained during the study. * Females of child-bearing potential must have a negative serum pregnancy test and use (and agree to continue to use throughout the study) an acceptable form of contraception. Exclusion Criteria: * Persistent daily vomiting * Gastrectomy, bariatric surgery, fundoplication or vagotomy/pyloroplasty * Has had or plans to have endoscopic pyloric injections of botulinum toxin within 6 months prior to the Screening Visit or during the study. * NG, PEG or PEJ feeding tube within 2 weeks prior to the Screening Visit * Required in-patient hospitalization for treatment of gastroparesis within 2 weeks prior to the Screening Visit * Required parenteral nutrition for treatment of gastroparesis within 2 months prior to the Screening Visit * Active gastric pacemaker within 3 months prior to the Screening Visit * Participated in an investigational study within 30 days prior to the Screening Visit * Chronic severe diarrhea * Diabetic ketoacidosis that required inpatient hospitalization within 30 days prior to the Screening Visit * History of any eating disorder within 2 years prior to the Screening Visit * Chronic obstructive pulmonary disease (COPD) or chronic asthma * Chronic smoker that is unable or unwilling to abstain from smoking during the two visits that the gastric emptying breath test will be performed * History of risk factors for Torsades de Pointes * Corrected QT interval calculated using Fredericia's formula \>= 500 msec, recorded and confirmed on any of the three ECG assessments performed during the screening period * Bradycardia or hypotension assessed as clinically-significant by the investigator * Requires treatment with concomitant medication that is a substrate of Cytochrome P450 isoenzyme 3A4 and known to have a clinically recognized risk for Torsades de Pointes * History of acute myocardial infarction, unstable angina or a transient (cerebral) ischemic attack within 12 months prior to the Screening Visit * History of severe depression, psychiatric disorder or cognitive impairment * History of alcohol or drug abuse or dependency within 2 years prior to the Screening Visit * Taking opiates for abdominal pain * Known history of Hepatitis B or C or HIV infection * Requires dialysis or elevated creatinine at the Screening Visit * Abnormal liver function tests at the Screening Visit * Uncontrolled hypo- or hyperthyroidism * Adrenal insufficiency * Active malignancy other than basal cell or squamous cell carcinoma of the skin * Pregnant or breast-feeding * Allergies to components of the breath test meal or severe lactose intolerance * Any other medical condition or social circumstance that, in the investigator's opinion, makes it inappropriate for the patient to participate in this clinical trial