Transdermal administration of ibuprofen-loaded hexagonal liquid crystal gel for enhancement of drug concentration in the uterus: in vitro and in vivo evaluation

Primary dysmenorrhea is a common disease in women, and oral administration of Ibuprofen (IBU) is associated with first-pass effects and gastrointestinal irritation. Here, we developed ibuprofen-loaded hexagonal liquid crystal (IBU HLC) gel for transdermal administration. In this study, the structure of prepared IBU HLC was characterized using polarizing microscopey (PLM) and small angle X ray diffraction (SAXS). In vitro drug release behavior and percutaneous penetration were investigated, and drug transdermal behavior was observed by confocal laser scanning microscope (CLSM). Finally, the pharmacokinetic profile and tissue distribution were investigated after transdermal administration. The PLM and SAXS results showed that the inner structure of IBU HLC was hexagonal phase. Moreover, in vitro release, skin permeation and CLSM demonstrated that IBU HLC had an excellent sustained-release effect, and a good transdermal penetration effect accompanied by the combination of multiple percutaneous routes. Pharmacokinetic studies indicated that IBU entered the blood circulation through abdominal transdermal administration in small amounts, mainly entering the uterus, and had a certain targeting ability. In conclusion, the IBU HLC gel would be a promising sustained-release preparation for transdermal administration to relieve dysmenorrhea with a significant drug concentration in the uterus.