Percutaneous absorption enhancement of thiocolchicoside with different approaches: in vitro and ex vivo evaluation

ABSTRACT Al-zawati, M (2022). Percutaneous Absorption Enhancement of Thiocolchicoside with Different Approaches: In Vitro and Ex Vivo Evaluation. Yeditepe University Institute of Health Sciences, Drug and Cosmetics Production Technology Master Program, İstanbul. Thiocolchicoside (THC) as analgesic, anti-inflammatory, muscle relaxant drug, hydrophilic (relatively high MW, 563.3) have been chosen to present the behavior of hydrophilic and relatively high MW drugs which is not favorable for the permeation through the skin. To achieve our thesis aim which is study and evaluate the skin permeation enhancement of hydrophilic drugs and their topical penetration capability by using different drug delivery approaches, THC gel formulations were prepared by using 3 different gel polymers (HPMC, Chitosan, Carpobol) with 3 different percentages of each polymer, the permeation study was performed by Franz cells diffusion apparatus using the artificial membrane to choose the best percentage of each polymer, then with pig skin as permeation membrane to choose the best gel polymer type as suitable THC gel vehicle. In the third step, we hypothesized that preparing THC-loaded liposomes (one of the new drugs nanovesicles carriers' delivery systems) would increase THC permeation. Final step was (pig skin microporation) by Dermaroller® (mechanical microneedles) to create microchannels in pig skin as permeation membrane. Commercial marketed cream and ointment were involved in every step to compare the results with them and evaluate the skin permeation enhancement of prepared gel formulations. Samples analyzed by UV spectrophotometer; data statistically analyzed by GraphPad Prism v.5.04 program. Final result showed that THC in chitosan gel 2.5% formulation is most promising THC topical formulation, and has the highest drug release profile across pig skin after Dermaroller® application. We suggest the use of different types, sizes, and lengths of Dermaroller® must be evaluated with the same formulation in future studies. Keywords: Thiocolchicoside; Franz diffusion cell ; Liposomes; Dermaroller; Topical formulation; HPMC; Chitosan; Carpobol.