Improved transdermal delivery of novel cannabinoid-loaded patches using Eudragit matrix

Abstract

The main active cannabinoids in extracts of Cannabis sativa L., cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA), are known for their pharmacological effects, including anti-inflammatory, analgesic, psychedelic, anti-cancer, and anti-spasmodic activities. This study aimed to develop adhesive cannabinoid-loaded transdermal patches (CLTPs) to enhance the skin permeation of the active cannabinoids, CBDA and THCA, and evaluate their stability. Optimized CLTPs were prepared in 1.5 % (w/w) polyvinyl alcohol-coated petri dishes using a solvent casting technique. The casting solution consisted of mixtures of isopropyl alcohol and ethanol, along with Eudragit®E100, succinic acid, dibutyl phthalate, and permeation enhancers such as oleic acid, isopropyl myristate, mixtures of oleic acid and isopropyl myristate, ethoxydiglycol, sesame oil, and co-polymer (Kollidon®VA64). The physicochemical properties of the patches were characterized by uniformity, thickness, drug content, swelling, and mechanical properties. The in vitro release studies of CBDA and THCA through a synthetic hydrophobic membrane using various release enhancers from these patches were conducted using Franz diffusion cells. Using ethoxydiglycol as a release enhancer demonstrated the highest release profile for both cannabinoids. The steady-state flux values of CBDA and THCA were 3.83 ± 0.45 μg/cm2/h (1.85-fold compared to the control) and 0.72 ± 0.14 μg/cm2/h (1.54-fold compared to the control) at 8 h. The stability studies of CLTPs demonstrated that both remained stable at 4 °C for at least 90 days. In conclusion, transdermal patches containing cannabinoids have been successfully developed and characterized. These findings offer a promising avenue for further investigation of CLTPs, as they could serve as a versatile formulation strategy for pharmaceutical products.