Development and stability of semisolid preparations based on Gardenia jasminoides Ellis extract

The fruit of Gardenia jasminoides Ellis has been traditionally used as a Chinese medicine for centuries in China, as well as in other Asian countries [1]. The major and characteristic constituents of Gardenia fruit are iridoid glycosides such as geniposide, gardenoside, genipin-1-β-gentiobioside, geniposidic acid, acetylgeniposide, scandoside methyl ester, shanzhiside and gardoside. Modern clinical and pharmacological research has revealed that Gardenia fruit has anti-inflammatory properties, cytotoxic effects, as well as protective against oxidative damage [1,2]. In the Chinese Pharmacopoeia a topical application of the fruit of gardenia, powdered and mixed with water is reported [8]. Gardenia fruit also represents the principal effective ingredient of a preparation with antiinflammatory and analgesic properties, „Zhongtong Caji“, a kind of liniment for external use, formulated with more than ten different herbal drugs [3]. The development of three semisolid preparations (anphyphil cream, sepigel and natrosol gel) based on Gardenia jasminoides Ellis extract is reported. Aqueous methanol (50% v/v) was selected in order to exhaustively extract the active constituents, iridoids (20% w/w). Stability of the developed preparations were investigated according to ICH guidelines. In vivo permeation of three selected formulations is investigated using the „skin stripping“ test, according to the FDA, in healthy subjects. Analysis of iridoids both in the extract and in the stratum corneum were performed by HPLC-DAD-MS method. The sepigel gel showed the best stability and release profile in the in vivo tests. References: 1. Wang Y et al. (2010) Int J Pharm 392: 72–77. 2. Park E-H et al. (2003) Phytother Res 17: 961–962. 3. Pharmacopoeia of the People's Republic of China (2005) vol.1, 95–96.