Here is the design of a clinical trial:

Official Title: A Random, Double-blind, Parallel, Placebo-controlled, Multi-center Study of Shuxuetong for Prevention of Recurrence in Acute Cerebrovascular Events With Embolism

Included conditions:
- Embolic Stroke

Study Armgroups:
- {'label': 'Shuxuetong Injection', 'type': 'EXPERIMENTAL', 'description': 'Shuxuetong Injection,12ml,ivgtt,day1; Shuxuetong Injection,6ml,ivgtt,day2 to day10;', 'interventionNames': ['Drug: Shuxuetong Injection']}
- {'label': 'Placebo Injection', 'type': 'PLACEBO_COMPARATOR', 'description': 'Placebo Injection,12ml,ivgtt,day1; Placebo Injection,6ml,ivgtt,day2 to day10;', 'interventionNames': ['Drug: Placebo Injection']}

Interventions:
- {'type': 'DRUG', 'name': 'Shuxuetong Injection', 'description': 'intravenous drip', 'armGroupLabels': ['Shuxuetong Injection'], 'otherNames': ['Shuxuetong']}
- {'type': 'DRUG', 'name': 'Placebo Injection', 'description': 'intravenous drip', 'armGroupLabels': ['Placebo Injection'], 'otherNames': ['Placebo']}

Primary Outcomes:
- {'measure': 'Symptomatic or Asymptomatic New Cerebral Infarction', 'description': 'Those patients who are still alive at 10 days after randomization will be contacted to set up a follow-up clinical visit. Information of recurrent symptomatic cerebral infarction will be collected and MRI examination will be performed to detect asymptomatic new cerebral infarction.', 'timeFrame': '10 days'}

Please estimate the sample size based on the assumption: 
90% power, two-sided α of 0.05, 5% loss to follow-up
Sample size
        The estimated sample size for the study is 2416 subjects. With a sample size of 2416 patients, the study has 90% power to detect a relative risk reduction of 20% with an assumed 30% event rate of primary outcome in the control group at two-sided Î± of 0Â·05 with the t-test for two independent proportions. Sample size calculation is based on the primary outcome with inflation to account for 5% loss to follow-up.