Study design
A randomised, prospective, parallel-group, single-centre clinical trial was designed to investigate the efficacy of three different modalities of treatment: betamethasone mouthwash, colchicine tablets, and a combination of the two. The trial was conducted in 12 month period and in compliance with the principles of the Declaration of Helsinki (2013), the principles of International Council for Harmonisation- Good Clinical Practice (ICH-GCP), and all the applicable regulatory requirements. The study was approved by the Guy’s Research Ethics Committee and the Medicines and Healthcare Products Regulatory Agency. This clinical trial was fully registered with The International Standard Randomised Clinical Trial Number (ISRCTN). Written informed consent was obtained from all participants.