title: Novel artemisinin and curcumin micellar formulations: drug solubility studies by NMR spectroscopy.
abstract: Artemisinin, a potent antimalarial drug derived from Artemisia annua L., and curcumin, a polyphenol extracted from the roots of Curcuma longa L., are reported to exert a synergistic antimalarial action, albeit manifesting a low bioavailability. In fact, both these molecules are poorly soluble in aqueous environments. In this study, we report a DOSY investigation of the solubilisation capacity of micelles of sodium dodecyl sulphate (SDS) for artemisinin and curcumin, individually and in combination. The aqueous solubility of artemisinin was enhanced approximately 25-fold by 40 mM SDS, and 50-fold by 81 mM SDS, while that of curcumin was increased to 2 mM by 81 mM SDS. In addition, we performed model studies on the use of the surface-active radical scavenger octanoyl-6-O-ascorbic acid (ASC8) to combine solubilisation with protection against oxidation for the chemically labile artemisinin. A 16-fold enhancement of artemisinin solubility was measured in a solution containing 40 mM SDS and 60 mM ASC8. Even after treatment with 60 mM hydrogen peroxide, more than a 30-fold excess, almost half the artemisinin remained, suggesting a potentially useful combination of the surface activity and antioxidant properties of the novel binary SDS:ASC8 system.
authors.affiliation: Department of Pharmaceutical Sciences, University of Florence, 50019 Sesto Fiorentino, FI, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lapenna
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Bilia
authors.forename: Gareth A
authors.initials: GA
authors.lastname: Morris
authors.forename: Mathias
authors.initials: M
authors.lastname: Nilsson
mesh_terms: D000962:Antimalarials / Q000008:administration & dosage / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry; D037621:Artemisinins / Q000008:administration & dosage / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003474:Curcumin / Q000008:administration & dosage / Q000737:chemistry*; D004058:Diffusion; D006861:Hydrogen Peroxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D000962:Antimalarials; D000975:Antioxidants; D037621:Artemisinins; D008823:Micelles; D016877:Oxidants; D013501:Surface-Active Agents; C031327:artemisinin; D006861:Hydrogen Peroxide; D003474:Curcumin