Smart Materials – The New Way to Developing Transdermal Drug Delivery Systems by Laser Ablation Technology

Using the dual pulsed laser (DPL) ablation technique applied to a target made of hemp seeds pressed in a stainless steel ring, thin layers were deposited on the glass support and on the hemp fabric. In order to improve the absorption of laser radiation by the target material (the ablation yield of hemp seeds being a low one), two procedures were used. The first consisted of including in the laser irradiated spot a portion of the stainless steel ring in which the hemp seed target is located, resulting in thin layers HS-DPL/glass and HS-DPL/hemp fabric. In order to obtain biocompatible thin layers, in the second process hemp seeds were mixed with turmeric powder whose effectiveness in interaction with laser radiation was known from previous studies, resulting in HST-DPL/glass and HST-DPL/hemp fabric thin layers. The ATR spectroscopic analyzes performed with the Moicro-FTIR technique highlighted the phenolic compounds specific to hemp, namely the cannabinoids tetrahydrocannabinol (THC) and cannabinidol (CBD), as well as ferulic and coumaric phenolic acids and also functional groups of other compounds, such as amides. To distinguish the peaks of IR vibrations, the ATR spectra were also compared with the spectra obtained by numerical simulation using Gaussian 6 software. Scanning electron microscopy (SEM), atomic force microscopy (AFM), as well as substance transfer tests revealed the microgranular structure of the thin layers. The transfer to filter paper of microparticles from thin layers deposited on hemp fabric (HS-DPL/hemp fabric and HST-DPL/hemp fabric) under temperature conditions similar to those of the human body demonstrated that the thin layers are suitable for the manufacture of transdermal drug delivery systems, thus exploiting the full pharmacological potential of hemp seeds according to the”whole plant medicine” or "entourage effect" concept.