Tolerability profile of topical cannabidiol and palmitoylethanolamide: a compilation of single‐centre randomized evaluator‐blinded clinical and in vitro studies in normal skin

Abstract

Background. An increasing number of studies have investigated the adverse effect profile of oral cannabinoids; however, few studies have provided sufficient data on the tolerability of topical cannabinoids in human participants. Aim. To assess the tolerability profile of several commercial topical formulations containing cannabidiol (CBD) and palmitoylethanolamide (PEA) on the skin of healthy human participants. Methods. Three human clinical trials and one in vitro study were conducted. The potential for skin irritation, sensitization and phototoxicity of several products, were assessed via patch testing on healthy human skin. The products assessed included two formulations containing CBD and PEA, one containing hemp seed oil and four concentrations of CBD alone. Ocular toxicity was tested using a traditional hen's egg chorioallantoic membrane model with three CBD, PEA and hemp seed oil formulations.Results. There was no irritation or sensitization of the products evident via patch testing on healthy participants. Additionally, mild phototoxicity of a hemp seed oil product was found at the 48-h time point compared with the negative control. The in vitro experiment demonstrated comparable effects of cannabinoid products with historically nonirritating products. Conclusion. These specific formulations of CBD-and PEA-containing products are nonirritating and nonsensitizing in healthy adults, and further encourage similar research assessing their long-term safety and efficacy in human participants with dermatological diseases. There are some limitations to the study: (i) external validity may be limited as formulations from a single manufacturer were used for this study, while vast heterogeneity exists across unregulated, commercial CBD products on the market; and (ii) products were assessed only on normal, nondiseased human skin, and therefore extrapolation to those with dermatological diseases cannot be assumed.

The effect of cannabinoids on wound healing: A review

“…However, given the various formulations that are in the market and the difficulty in regulating topical cannabinoids, these results are likely not generalizable to all cannabinoid products. 55 Further research is needed to understand the full spectrum of side effects of topical cannabinoids.…”

Phytocannabinoids in the Pharmacotherapy of Psoriasis

“…The use of oil contributes to the reduction of analgesic pharmacotherapy. Possibility: using preparations on skin exposed to solar radiation [124] Despite Despite the similarities of various phytocannabinoids in their biological and biomedical effects, in addition to the extensively researched effects of CBD, recent years have brought new detailed data on other components of Cannabis sativa, including THC and CBG. CBG, with a broad spectrum of biological effects on skin cells in vitro, including antioxidant, anti-inflammatory, anti-acne and anti-aging properties, has also been shown in clinical trials to be both safe and effective in maintaining skin health, including reducing redness [52,121].…”

“…Both the individual components, mainly phytocannabinoids, and Cannabis sativa extracts have been intensively studied in recent years in terms of their biological effects, especially those that protect healthy skin and heal the affected skin ( Table 3 ) [ 52 , 109 , 121 , 122 , 123 , 124 ]. However, despite the demonstrated wide range of biological properties, there is very little evidence based on clinical trials indicating the possibility of using specific preparations containing phytocannabinoids in medical practice.…”

Efficacy and Safety of Cannabis Transdermal Patch for Alleviating Psoriasis Symptoms: Protocol for a Randomized Controlled Trial (CanPatch)

“…With the topical application of CBD, previous studies have not reported serious adverse events. Minorities experience minor adverse events, including erythema, skin irritation or pain, changes in hair or skin color, somnolence, and diarrhea [31,32,[61][62][63][64][65][66].…”