Chatterjee 1977.

Methods	R, DB, PC, parallel groups Cream applied to site of injury 3 times daily for 6 days Assessment at baseline, 2, 6 days
Participants	Soft tissue injuries (recent) N = 51 M/F not reported Age not reported Baseline pain on passive movement moderate or severe in all but 3 participants
Interventions	Benzydamine HCl cream 3%, 3 x daily, n = 25 Placebo cream, n = 25 (5 active, 6 placebo participants also received ultrasound) No other topical agent allowed
Outcomes	Pain on passive movement: 4‐point scale (responder = "absent" or "slight") Tenderness with pressure: 4‐point scale (responder = "absent" or "slight") Adverse events Withdrawals and exclusions
Notes	Oxford Quality Score: R1, DB2, W1. Total = 4/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"predetermined randomised schedule"
Allocation concealment (selection bias)	Low risk	Sealed copy of schedule held by investigator and duplicate copy kept by clinical trial co‐ordinator. Looked at only in event of adverse reaction (not necessary)
Blinding (performance bias and detection bias) All outcomes	Low risk	"indistinguishable .... in appearance and consistency"
Incomplete outcome data (attrition bias) All outcomes	Low risk	2% lost to follow‐up, no withdrawals due to adverse events. Responder analysis
Size	Unclear risk	< 50 participants per treatment arm