Bioavailability of an R-α-Lipoic Acid/γ-Cyclodextrin Complex in Healthy Volunteers

• Main Authors: Naoko Ikuta, Hinako Okamoto, Takahiro Furune, Yukiko Uekaji, Keiji Terao, Ryota Uchida, Kosuke Iwamoto, Atsushi Miyajima, Takashi Hirota, Norihiro Sakamoto
• Format: Article
• Language: English
• Published: MDPI AG 2016-06-01
• Series: International Journal of Molecular Sciences
• Subjects: R-α-lipoic acid; cyclodextrin; bioavailability; pharmacokinetics; healthy volunteers; clinical study; oral administration
• Online Access: http://www.mdpi.com/1422-0067/17/6/949

R-α-lipoic acid (R-LA) is a cofactor of mitochondrial enzymes and a very strong antioxidant. R-LA is available as a functional food ingredient but is unstable against heat or acid. Stabilized R-LA was prepared through complexation with γ-cyclodextrin (CD), yielding R-LA/CD. R-LA/CD was orally administered to six healthy volunteers and showed higher plasma levels with an area under the plasma concentration-time curve that was 2.5 times higher than that after oral administration of non-complexed R-LA, although the time to reach the maximum plasma concentration and half-life did not differ. Furthermore, the plasma glucose level after a single oral administration of R-LA/CD or R-LA was not affected and no side effects were observed. These results indicate that R-LA/CD could be easily absorbed in the intestine. In conclusion, γ-CD complexation is a promising technology for delivering functional but unstable ingredients like R-LA.