Supplementary Material for: Efficacy and safety of transdermal medical cannabis (THC:CBD: CBN formula) to treat painful diabetic peripheral neuropathy of the lower extremities

Abstract Introduction: Diabetic peripheral neuropathy (DPN) represents a prevalent neurological complication affecting millions of patients globally. This clinical investigation evaluated the therapeutic efficacy and safety profile of a novel transdermal medical cannabis formulation (THC:CBD:CBN) in treating painful DPN of the lower extremities. Methods: This phase III, double-blind, placebo-controlled, randomized clinical trial was conducted at Don Chan Hospital, Thailand, enrolling 100 participants over a 12-week intervention period. Using a computer-generated randomization sequence, participants were allocated to receive either the standardized cannabis formulation or a matched placebo. The primary outcome measure comprised pain intensity assessment using the validated Thai version of the Neuropathic Pain Symptom Inventory (NPSI-T). Secondary outcomes encompassed treatment-emergent adverse events and dermatological manifestations. Statistical analyses were performed using SPSS Version 28.0, incorporating Generalized Estimating Equation (GEE) modeling and Analysis of Covariance (ANCOVA). The study protocol received approval from the Institutional Review Board of Khon Kaen University and the Kalasin Provincial Public Health Office Ethics Committee, with trial registration in the Thai Clinical Trials Registry. Results: The intervention group demonstrated statistically significant reductions in NPSI-T scores across all measured dimensions (p