Eremantholide C from aerial parts of Lychnophora trichocarpha, as drug candidate : fraction absorbed prediction in humans and BCS permeability class determination.

Abstract

Background Lychnophora trichocarpha (Spreng.) Spreng. ex Sch.Bip has been used in folk medicine to treat pain, inflammation, rheumatism and bruises. Eremantholide C, a sesquiterpene lactone, is one of the substances responsible for the anti-inflammatory and anti-hyperuricemic effects of L. trichocarpha. Objectives Considering the potential to become a drug for the treatment of inflammation and gouty arthritis, this study evaluated the permeability of eremantholide C using in situ intestinal perfusion in rats. From the permeability data, it was possible to predict the fraction absorbed of eremantholide C in humans and elucidate its oral absorption process. Methods In situ intestinal perfusion studies were performed in the complete small intestine of rats using different concentrations of eremantholide C: 960 μg/ml, 96 μg/ml and 9.6 μg/ml (with and without sodium azide), in order to verify the lack of dependence on the measured permeability as a function of the substance concentration in the perfusion solutions. Results Eremantholide C showed Peff values, in rats, greater than 5 × 10−5 cm/s and fraction absorbed predicted for humans greater than 85%. These results indicated the high permeability for eremantholide C. Moreover, its permeation process occurs only by passive route, because there were no statistically significant differences between the Peff values for eremantholide C. Conclusion The high permeability, in addition to the low solubility, indicated that eremantholide C is a biologically active substance BCS class II. The pharmacological activities, low toxicity and biopharmaceutics parameters demonstrate that eremantholide C has the necessary requirements for the development of a drug product, to be administered orally, with action on inflammation, hyperuricemia and gout.