Study design
ICH
This was a randomised, controlled, crossover clinical study carried out at a single site operated by Simbec-Orion in Merthyr Tydfil, Wales, U.K. The study was registered on the ISRCTN registry (ISRCTN80837297). The experimental protocol was approved by the NHS Health Research Authority, Wales Research Ethics Committee 1 (reference number 20/WA/0264) prior to study commencement. The study was conducted in accordance with the protocol and under the principles of both the International Council for Harmonisation (ICH) of Technical Requirements for Pharmaceuticals for Human Use Guideline for Good Clinical Practice (GCP) E6(R2) and European Union General Data Protection Regulation (GDPR). Written informed consent was obtained from all participants prior to participation in the study and before undergoing any study procedures, including screening assessments. All participants were informed that they were free to quit smoking/using e-cigarettes and withdraw from the study, or to withdraw their consent to participate, at any time.