RESUMEN
BACKGROUND: Chitosan-EDTA is an interesting matrix for dermal delivery; however, the adhesiveness is too small. Therefore, the purpose of this study was to investigate chitosan-glycolic acid as possible dermal matrix for progesterone in comparison to chitosan-EDTA and carrageenan. METHOD: After preparation of the chitosan-glycolic acid salt and characterization by NMR and FTIR, tensile studies using porcine skin and rheology measurements as well as standard diffusion experiments using dermatomed porcine skin were performed. RESULTS: Results showed an improved skin adhesiveness of chitosan-glycolic acid and increased viscosity. Skin diffusion studies indicated the highest cumulative permeation of progesterone after 48 hours from chitosan-glycolic acid followed by carrageenan and chitosan-EDTA. A possible explanation might be a longer residence time on skin caused by the higher adhesiveness and with it higher progesterone skin permeation. CONCLUSION: Chitosan-glycolic acid can be recommended as a suitable polymer for hydrogels and an adhesive matrix for a transdermal application of progesterone exhibiting excellent skin adhesiveness and permeation properties.