Here is the design of a clinical trial:

Official Title: Rectally Administered Indomethacin to Prevent Post-ESWL-pancreatitis (RIPEP)

Included conditions:
- Pancreatitis

Study Armgroups:
- {'label': 'Indomethacin', 'type': 'EXPERIMENTAL', 'description': 'Subjects will be randomized to receive a 100-mg indomethacin suppository 30 min before ESWL.', 'interventionNames': ['Drug: indomethacin suppository']}
- {'label': 'Glycerin', 'type': 'PLACEBO_COMPARATOR', 'description': 'Subjects will be randomized to receive either a 100-mg identical-appearing placebo (glycerin suppository) 30 min before ESWL.', 'interventionNames': ['Drug: Glycerin Suppository']}

Interventions:
- {'type': 'DRUG', 'name': 'indomethacin suppository', 'description': '100mg rectal indomethacin 30min before ESWL', 'armGroupLabels': ['Indomethacin']}
- {'type': 'DRUG', 'name': 'Glycerin Suppository', 'description': '30min before ESWL', 'armGroupLabels': ['Glycerin']}

Primary Outcomes:
- {'measure': 'the Incidence of Post-ESWL Pancreatitis', 'description': 'Patients were identified as post-ESWL pancreatitis if meeting two out of three criteria: pain consistent with acute pancreatitis; amylase or lipase\\>3 times normal limit; characteristic findings on imaging, in according to the Revised Atlanta International consensus.', 'timeFrame': 'up to 1 months'}

Please estimate the sample size based on the assumption: 
The trial assumes a one-sided alpha of 0.025, a power of 80%, and a possible withdrawal rate of 5%.
Sample size
          The sample size calculation is based on our previous research on the incidence rate of post-ESWL pancreatitis. Post-ESWL pancreatitis occurs in 6.8% of the patients for the first P-ESWL sessions and accounting for 69.4% of complications [9]. The RIPEP trial is a superiority trial in which the sample size is based on the assumption that rectally administered indomethacin reduces the incidence of the primary endpoint by a relative reduction of 50%. This amounts to an expected incidence of post-ESWL in the rectally administered indomethacin group of 3.4%. Assuming a one-sided alpha of 0.025 and a power of 80%, 1370 patients (685 per arms) would be necessary to detect a 6.8 to 3.4% reduction of post-ESWL pancreatitis, including a possible withdrawal rate of 5%.