betadex and astaxanthine

Storage stability of astaxanthin/hydroxypropyl-β-cyclodextrin (HPCD) inclusion complex was evaluated and which was compared with native astaxanthin. The storage stability of astaxanthin was enhanced after included in HPCD under 4 °C and 25 °C storage conditions. Antioxidant activity of astaxanthin/HPCD inclusion complex was also assayed using ascorbic acid as a control sample. The reducing power and DPPH radical scavenging activity of native astaxanthin were lower than ascorbic acid, while which of the complex were higher at low concentration for the good water solubility. The hydroxyl radical scavenging activities of astaxanthin and astaxanthin/HPCD complex far outclassed that of ascorbic acid, and the activity of the complex was a little lower than that of the native astaxanthin.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Biphenyl Compounds; Drug Stability; Drug Storage; Free Radical Scavengers; Hydroxyl Radical; Oxidation-Reduction; Picrates; Xanthophylls

The structure and complex mode of the inclusion complex of astaxanthin with hydroxypropyl-β-cyclodextrin (HPCD) were investigated by UV, FTIR, 1H NMR and molecular modeling test. UV, FTIR and 1H NMR results indicated that the hexatomic ring of the astaxanthin molecules were partly included into the HPCD cavities. The implementation of molecular modeling test confirmed that the complexation could reduce the energy of the system and the complex of 2:1 host-guest stoichiometry had the lowest ΔE value, -30.57 kcal/mol, two hexatomic ring ends of one astaxanthin molecule inserted into two HPCD cavities respectively, and that should be the most predominant configuration.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antioxidants; beta-Cyclodextrins; Models, Molecular; Proton Magnetic Resonance Spectroscopy; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Xanthophylls

Carotenoids are the most widely distributed natural pigments, with over 600 individual compounds identified and characterized from natural sources. A few are commercially important molecules, having found utility as additions to animal feed in the aquaculture, poultry, and swine feed industries. The majority are lipophilic molecules with near zero inherent aqueous solubility. Many different methods have been developed to make the carotenoids "water dispersible," as true water solubility has not been described. Astaxanthin (3,3'-dihydroxy-beta, beta-carotene-4,4'-dione) is a commercially important oxygenated carotenoid that has gained wide acceptance as a feed additive in the $50 billion salmon and trout aquaculture industry. Recently, interest in the human health applications of astaxanthin has increased, with astaxanthin receiving approval as a dietary supplement in several countries, including the United States. Moving astaxanthin into a pharmaceutical application will require a chemical delivery system that overcomes the problems with parenteral administration of a highly lipophilic, low molecular weight compound. In the current study, the ability of sulfobutyl ether beta-cyclodextrin (sodium), as the Captisol(R) brand, to increase the aqueous water solubility of crystalline astaxanthin was evaluated. Complexation of crystalline astaxanthin with Captisol increased the apparent water solubility of crystalline astaxanthin approximately 71-fold, to a concentration in the 2 microg/mL range. It is unlikely that this increase in solubility will result in a pharmaceutically acceptable chemical delivery system for humans. However, the increased aqueous solubility of crystalline astaxanthin to the range achieved in the current study will likely find utility in the introduction of crystalline astaxanthin into mammalian cell culture systems that have previously been dependent upon liposomes, or toxic organic solvents, for the introduction of carotenoids into aqueous solution.

Topics: Adjuvants, Immunologic; beta Carotene; beta-Cyclodextrins; Chemistry, Pharmaceutical; Crystallization; Cyclodextrins; Pharmaceutical Solutions; Solubility; Water; Xanthophylls