Biocompatibility and anti-inflammatory effects of Thai cannabidiol-containing topical anesthetic gel prototype in a dermal irritation test

Abstract

The objective of this study is to investigate and compare the effect of cannabidiol (CBD)-containing and non-CBDtopical anesthetic gel prototypes on skin irritation in rabbits at 24, 48, and 72 h post-application. Topical anesthetic gelprototypes containing 0.1% CBD and without CBD were developed. Six rabbits (Oryctolagus cuniculus) were used forskin irritation testing according to ISO 10993-23: 2021. The animals were randomly and equally divided into two groups(CBD and non-CBD gel groups). The gels were applied to the animals’ skin at the dorsal area of the flank with goodcontact for 4 h. Distilled water was used as the control. After exposure, skin reactions (erythema and oedema scores),the primary irritation score, and the primary irritation index were evaluated immediately and at 24, 48, and 72 h post-application. Data were analyzed using the SPSS program with a paired t-test (P < 0.05). Both the CBD and non-CBDgroups exhibited mild skin irritation. However, the CBD group showed a lower primary irritation index, particularlyat the 72-h time point. In conclusion, the CBD-containing topical anesthetic prototype has mild skin irritation. CBD mayhelp alleviate the irritating effects of topical local anesthetics.