A gelled emulsion is a colloidal material in which oil-in-water emulsion coexists within a gel network

However, despite these regulations, several cases of contaminated cosmetic products have occurred on the UAE market . For example, a survey of 100 cosmetics and other personal care products available in the UAE found that 13% and 5% of samples were contaminated by yeast/mould and aerobic mesophilic bacteria, respectively . Another study in the same context revealed that 13% of the tested cosmetic and personal care products not only contained formaldehyde above the recommended levels but also did not state on the label that the product contained free formaldehyde or formaldehyde releasers . To the best of our knowledge, our study is the first to assess the quality of cannabinoidbased cosmetic products available on the UAE market. In particular, it aims to quantify the presence of undeclared tetrahydrocannabinol, specifically THC and THCA, in these products.

The findings will contribute to ensuring compliance with current regulations and aid in the development of new methods for identifying adulterants in cannabinoid-based cosmetic protects with the aim of ensuring public safetyStores selling cosmetics and other personal care products were identified via a search of local business directories containing the details of the pharmacies, parapharmacies, and health product sellers in the UAE. The search revealed 2183 separate outlets, which were entered into an Excel spreadsheet that represented the sampling framework, along with all relevant details, e.g., each business name, business address, email address, and phone number. The business ID numbers were subsequently used to generate the study sample via basic random-sample selection. Then, the selected locations were visited to sample the products Figure S1. The main selection criteria were cosmetic or personal care products that were labelled as containing either cosmetic oil with CBD or hemp oil . One package of each product that met both criteria was randomly chosen at each location regardless of its country of manufacture. To enable tracking and to prevent a product from being sampled more than once, eachsample was assigned a code reference number.

The following details were recorded for each sample: product name, brand name, batch number, barcode, dosage form, item category, subcategory, size/volume, recommended dose, country of origin/manufacturer, and from which store the product had been purchased. If identical products, i.e., with the same name, formulation, and manufacturer, were being sold at more than one outlet, the fifirst product to be sampled was tested, while the remaining samples were returned. Any products made by different manufacturers but bearing the same name or products offered in different formats, such as an emulsion and a cream, were considered distinct products and tested separately. The products were forwarded to a laboratory for testing on the day of collection.Despite a lack of research into the effectiveness of over-the-counter topical cannabinoidbased cosmetics, their availability on the market has recently increased. Manufacturers advertise these products as safe treatments for various skin conditions, such as acne, psoriasis, and atopic dermatitis , or as a way to promote healthy hair. Nonetheless, the lack of scientific evidence on the safety and efficacy of these products remains a concern. Given this situation, the current study aimed to examine to what degree these products available on the UAE market contain undeclared tetrahydrocannabinol, specifically THCA and THC. The current study found that the sampled products had an average tetrahydrocannabinol content of 0.011%.

However, the regulatory regime of the UAE stipulates that cannabinoid-based products may contain no tetrahydrocannabinol chemicals, and the adulteration of these consumer products bears substantial risks that considerably outweigh any public health benefifits. Our study is the first to measure to what extent topical cannabinoid-based consumer products contain undeclared tetrahydrocannabinol, thereby contributing to the literature on the safety of cosmetic products containing cannabinoids. Previous research developed a method for detecting the constituents and metabolites of cannabis in hair, thereby allowing cannabis exposure to be determined . A study in the UK showed that using hemp oil to cosmetically treat hair can lead to the absorption of THC, cannabidiol , cannabinol , and, on rare occasions, even the metabolite 11-hydroxy-delta-9-tetrahydrocannabinol . This study also demonstrated that when volunteers applied hemp oil to their hair, 89% were found to have absorbed one or more constituents of cannabis, while 33% had absorbed the three major constituents, namely, CBD, THC, and CBN .