| الوصف: |
Topical therapy is an attractive choice for the treatment of skin disorders due to the targeting of drugs to the localized site in the skin tissue, such as, in depigmentary diseases that may causing the destruction of melanocytes, with prevalence among worldwide. Pharmaceutical emulsions emerge as a suitable solution for skin drug deposition, in spite of their thermodynamic instability, that makes their development a complex challenge in pharmaceutical technology, particularly W/O emulsions. In this dissertation, new vehicles, such as W/O emulsions, for the localized treatment of hypopigmentation, with a natural furanochromone (khellin), were developed. The physicochemical characterization of the vehicles, as well as, the rheological behaviour, the microstructure analysis and stability studies were part of the study. In vitro assays to evaluate drug release and permeation profiles are also performed. In addition, an in vivo sensorial analysis and an efficacy test was performed for the vehicles developed. This project started with the development of emulsions and six W/O emulsions were obtained, of which three were classic W/O emulsions and the other three W/O emulsions based on GELTRAP™ concept. All emulsions presented suitable macroscopic appearance and a good compatibility of the drug upon incorporation, maintaining overall the properties of the emulsion. In vitro release and permeation studies revealed that final emulsions presented similar profiles and the in vivo study confirmed also a good consumer acceptability. In conclusion, two potential vehicles were obtained for delivering khellin through targeted site of the skin, with the purpose of improving the treatment of hypopigmentation. W/O emulsions obtained have the peculiarity of remaining on the skin surface and therefore that should ensure drug concentration at the target sites. |