A Study on the Bioavailability of a Proprietary, Sustained-release Formulation of Astaxanthin.

contextAstaxanthin has been shown to provide important health benefits, such as functioning as an anti-inflammatory, antioxidant, anticancer, and cardioprotective agent. Astaxanthin is a lipid-soluble molecule with low oral bioavailability, which limits its therapeutic potential. The low oral bioavailability is due to dissolution limitations in the gastrointestinal fluids.

objectiveThe objective of this study was to compare the relative bioavailability of a proprietary sustained-release formulation of astaxanthin (astaxanthin-SR)-a micronized dispersion of astaxanthin oil that is 2.5% astaxanthin in a sustained-release matrix-with that of an unformulated astaxanthin oil containing 10% astaxanthin.

designA dissolution study compared the solubility of formulated and unformulated astaxanthin oils. The research team also performed a single-dose, 24-h crossover, uptake study.

settingThe dissolution study took place at BioActives (Worcester, MA, USA). The single-dose study was done at the MAZE Laboratories (Purchase, NY, USA).

participantsSix healthy male and female volunteers aged 21 to 66 y took part in the single-dose study. The participants were people from the community.

interventionThat proprietary formulation is a free-flowing paste that is able to form a stable dispersion in water and achieve sustained-release when presented in a capsule form. For the samples used in the dissolution study, hard gelatin capsules were filled either with the unformulated astaxanthin oil or with the proprietary astaxanthin-SR formulation, both with the equivalent of 10 mg of astaxanthin. For the single-dose study, participants received a 60-mg dose of astaxanthin in each form, as capsules, with a 15-d washout period between the 2 doses. The astaxanthin-SR capsules were administered after breakfast, and blood samples were drawn at 3, 8, 10, and 24 h postintervention. After a 15-d washout period, the protocol was repeated with astaxanthin oil capsules. OUTCOME MEASURES: For the dissolution study, the astaxanthin was quantified using spectrophotometry. For the single-dose study, plasma astaxanthin was quantified using reverse-phase high-performance liquid chromatography equipped with an ultraviolet-visible detector and a Phenomenex Synergy Hydro-RP column 150 × 4.6 mm, 4 μm (Phenomenex, Torrance, CA, USA) at room temperature.

resultsThe dissolution study indicated that the astaxanthin-SR formulation formed a stable dispersion in the simulated gastric and intestinal fluids. The formulation also showed greater dissolution for 12 h at all points tested, compared with the astaxanthin oil, which showed no dissolution during the same period of 12 h. The results of the single-dose uptake study indicated that the astaxanthin-SR formulation was 3.6 times more bioavailable than astaxanthin oil, with

conclusionsThe formulation of astaxanthin oil in a sustained-release matrix significantly improved the absorption of astaxanthin. The formulation also reduced interindividual variations in absorption. Participants who were poor absorbers from the unformulated astaxanthin oil, showed higher absorption with the astaxanthin-SR formulation.