Improved efficacy of appetite suppression by lipoic acid particles prepared by nanocomminution

Abstract

Purpose: This article was intended to improve the efficacy of alpha-lipoic acid (ALA) for appetite suppression by controlling the particle size and self-polymerization of ALA. Methods: ALA was fabricated into micro- and nanoparticles, and the efficacy and in vitro release were investigated. Because of the self-polymerization of ALA into poly[3-(n-butane carboxylic acid)propyl]disulfide (PBCPD) by processing heat, low-speed rotation comminution was used to control PBCPD content. Results: The ALA particle size initially decreased and then increased after 10 hours of nanocomminution, indicating aggregation related to PBCPD formation. The in vitro release of ALA was significantly reduced by the existence of PBCPD. Interestingly, the reduction was not followed by a decrease in efficacy. Alternatively, the food intake was significantly reduced by ALA particles containing more than 30 mol% PBCPD. Conclusions: When the particle size and self-polymerization of ALA were carefully controlled, the efficacy on appetite suppression could be superior to water-soluble ALA salt. The ALA particles might have a composite nanostructure of ALA and PBCPD.

Keywords:

• Appetite suppression
• comminution
• lipoic acid
• nanoparticles
• self-polymerization

Acknowledgments

This research was supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Commerce, Industry and Energy, Republic of Korea. CHP thanks the Ministry of Knowledge Economy and Korea Industrial Technology Foundation through the Human Resource Training Project for Strategic Technology, BK21 Fellowship. The authors thank Dalim BioTech (Korea) for supplying ALA.

Declaration of interest: The authors report no conflicts of interest.