Essential Oil from the Twigs of Cinnamomum Cassia Mediated the Flexible Liposomes of the Total Glucosides of Peony for Arthritis Treatment

Abstract

Flexible liposomes (FL) have been developed as novel transdermal delivery systems. However, the skin barrier impairs the drug penetration and absorption. In this study, we designed, characterized and evaluated a total glucosides of Paeony (TPG) loaded FL (TFL) topically drug deliver system for arthritis treatment. The novelty is that the essential oil from the Twigs of Cinnamomum Cassia (EOCC) was incorporated in TFL as drug penetrating enhancer. Interestingly, the EOCC addition didn’t significantly change the characteristic parameters of the TFL in terms of morphology, size distribution, zeta potential, and entrapment efficiency. Remarkably, EOCC-embedded TGP-loaded FL (EOCC-TFL) dramatically prevented the drug leakage and improved the TGP skin penetration in vitro (4.6, 1.8, and 1.5 times higher than the TGP solution, TGP and EOCC mixture, and TFL, respectively). Moreover, despite of the low dose (175 mg/kg which was half dose of the TGP gavage group), this optimized formulation exhibited favorable anti-inflammatory effects in vivo on arthritis rats with significantly reduced swollen toe volume and serum inflammatory factor levels. This study lays solid foundation for the engineering liposomes with EOCC for transdermal drug delivery.