Here is the design of a clinical trial:

Official Title: Oral Huzhang Granules for Acute Gouty Arthritis: Protocol for a Randomized, Double-blind, Multicenter Clinical Trial

Included conditions:
- Gouty Arthritis

Study Armgroups:
- {'label': 'HZG intervention', 'type': 'EXPERIMENTAL', 'description': 'During the 5-day treatment period, participants in the Experimental group will receive 10 sacks of experimental granules. They will be instructed to take two sacks per day, one in the morning and one in the evening, in approximately 30 minutes after the meal.. The placebo etoricoxib will also be taken daily in the morning for 5 days.', 'interventionNames': ['Drug: Huzhang granule', 'Drug: Etoricoxib Placebo']}
- {'label': 'Etoricoxib intervention', 'type': 'ACTIVE_COMPARATOR', 'description': 'During the 5-day treatment period, participants in the Etoricoxib group will receive 5 Etoricoxib capsules. They will be instructed to take one capsule per day in the morning, at approximately 30 minutes after the meal. The placebo HZKL will also be taken daily in the morning for 5 days.', 'interventionNames': ['Drug: Etoricoxib', 'Drug: Huzhang granule Placebo']}
- {'label': 'Placebo intervention', 'type': 'PLACEBO_COMPARATOR', 'description': 'During the 5-day treatment period, participants in the Placebo group will receive 10 sacks of placebo HZG. They will be instructed to take two sacks per day, one sack in the morning and one in the evening, at approximately 30 minutes after the meal. And the placebo etoricoxib also be taken daily in the morning for 5 days.', 'interventionNames': ['Drug: Huzhang granule Placebo', 'Drug: Etoricoxib Placebo']}

Interventions:
- {'type': 'DRUG', 'name': 'Huzhang granule', 'description': 'Empty the content of one sachet into a mug, add 50ml warm water, stir until dissolved, add another 50ml hot water. Consume and complete all 100ml liquid mixture as a single dosage.', 'armGroupLabels': ['HZG intervention'], 'otherNames': ['Chinese Herbal Medicine']}
- {'type': 'DRUG', 'name': 'Etoricoxib', 'description': 'take one capsule per day in the morning, at approximately 30 minutes after the meal.', 'armGroupLabels': ['Etoricoxib intervention'], 'otherNames': ['Chemical drug']}
- {'type': 'DRUG', 'name': 'Huzhang granule Placebo', 'description': 'Empty the content of one sachet into a mug, add 50ml warm water, stir until dissolved, add another 50ml hot water. Consume and complete all 100ml liquid mixture as a single dosage.', 'armGroupLabels': ['Etoricoxib intervention', 'Placebo intervention'], 'otherNames': ['Chinese Herbal Medicine']}
- {'type': 'DRUG', 'name': 'Etoricoxib Placebo', 'description': 'take one capsule per day in the morning, at approximately 30 minutes after the meal.', 'armGroupLabels': ['HZG intervention', 'Placebo intervention'], 'otherNames': ['Chemical drug']}

Primary Outcomes:
- {'measure': 'Visual Analogue Score (VAS)', 'description': 'Visual Analogue Score is an often-used tool to measure subjective phenomena, which has shown good reliability and validity in terms of assessment of pain. In the clinical study of acute gout attack，it can be used as a tool to measure the degree of pain from 0 to 100 mm (with 0 being no pain and 100 being maximum pain)', 'timeFrame': 'Up to 5 days after treatment'}

Please estimate the sample size based on the assumption: 
Two-sided significance level (Î±) is set at 0.05, statistical power is set at 0.8, and a 20% loss to follow-up is considered.
Sample size
        The required sample size was calculated using an estimation formula based on the differences among the three sample rates [14, 17, 18]. A previous clinical study [19] reported that the response rates of the etoricoxib treatment, TCM treatment group, and placebo treatment groups were 63.89%, 42.5%, and 15.5%, respectively. Setting the two-sided significance level (Î±) at 0.05 and statistical power at 0.8, a minimum sample size of 74 participants per group (222 participants in total) was estimated to provide sufficient statistical power to detect a between-group difference of approximately 20% in treatment efficiency, defined as the change in analgesic effectiveness. Considering a 20% loss to follow-up, we aim to enroll 89 patients in each arm, that is, a total of 267 patients.