Here is the design of a clinical trial:

Official Title: Can the Prophylactic Administration of Tranexamic Acid Reduce Blood Loss After Robotic-assisted Radical Prostatectomy? The RARPEX (Robotic Assisted Radical Prostatectomy With TranEXamic Acid) Study.

Included conditions:
- Robotic-assisted Radical Prostatectomy

Study Armgroups:
- {'label': 'Tranexamic acid', 'type': 'EXPERIMENTAL', 'interventionNames': ['Drug: Tranexamic Acid Injectable Product']}
- {'label': 'Saline', 'type': 'PLACEBO_COMPARATOR', 'interventionNames': ['Drug: Placebos']}

Interventions:
- {'type': 'DRUG', 'name': 'Tranexamic Acid Injectable Product', 'description': 'A single dose of tranexamic acid, corresponding to 20 mg/kg in 100 ml saline, will be administered in the beginning of procedure.', 'armGroupLabels': ['Tranexamic acid']}
- {'type': 'DRUG', 'name': 'Placebos', 'description': '100 ml of saline will be administered in the beginning of the procedure.', 'armGroupLabels': ['Saline']}

Primary Outcomes:
- {'measure': 'Reduction of blood loss', 'description': 'The drop of hemoglobin level, weighted on gram of prostate or creatinin level.', 'timeFrame': '7 days after the procedure'}

Please estimate the sample size based on the assumption: 
Two-sample T tests allowing unequal variance, significance level (Î±) = 1%, power (1-Î²) = 90%, expected dropout rate = 33%.
Sample size calculation
        The sample size calculation is based on the data from our pilot study [29]. We used two-sample T tests allowing unequal variance with respect to the primary endpoint, which is the difference in hemoglobin level drop on postoperative day (POD) 1. The level of significance is set to 5 g. With Î± = 1% and Î² = 10%, a sample size of 64 patients per group is necessary to detect a clinically significant difference between the groups. With an expected dropout rate over 33%, we plan to enroll 200 patients in the study.