Examination of dissolution ratio of ß-carotene in water for practical application of ß-carotene amorphous solid dispersion.

ß-Carotene (BC) has an antioxidant effect that removes active oxygen in vivo and can reduce the risk of developing various diseases, but it is almost insoluble in water. Therefore, to develop highly effective BC functional food products, it is essential to increase its water solubility, which in turn can improve its absolute bioavailability. Recently, a BC amorphous solid dispersion (BC-SD) prepared using hot melt extruder technology had increased water solubility and improved absorption from the gastrointestinal tract. However, only a part of the BC in BC-SD could be dissolved in water. In this study, we evaluated whether the dissolution ratio of BC in water could be improved by examining the mixing ratio of BC and base materials in BC-SD. Results showed that by reducing the mixing ratio of BC to the base materials, the dissolution ratio of BC in water increased. It was also found that when BC-SD, which has the highest dissolution ratio, was intragastrically administered to rats, its absolute bioavailability was most increased. These results are useful findings that may help in reducing the costs associated with the BC-SD manufacturing process and will be an important part of our strategy for practical use in the future.

Improved Bioavailability of ß-Carotene by Amorphous Solid Dispersion Technology in Rats.

ß-Carotene (BC) is a natural lipophilic carotenoid mainly present in vegetables and fruits. Although it has various beneficial pharmacological activities, its bioavailability is low owing to its low water solubility. Recently, we reported that BC solid dispersion prepared using hot-melt technology with polyvinylpyrrolidone and sucrose fatty acid esters was in an amorphous state and showed the highest solubility. We hypothesized that the absorption of BC solid dispersion would be better because of its increased water solubility. To verify this, we conducted a pharmacokinetic analysis of BC for application in functional foods. Crystalline or amorphous BC was orally administered to rats. Blood was collected at various time points, and the BC concentration in the plasma was measured by HPLC. Oral administration of amorphous BC showed increased absorption in rats compared with that of BC crystals. Using blood samples from rats that were intravenously injected with the plasma of rats that had been orally administered BC, pharmacokinetic parameters could be calculated without using organic solvents or surfactants. It was possible to calculate various pharmacokinetic parameters under physiological conditions according to amorphous BC characteristics. Thus, we were able to determine the bioavailability of BC after oral administration. This simple technology to improve BC solubility without the use of organic solvents can be applied not only in the pharmaceutical industry but also in the food industry, and it therefore has high utility value.

ß-Carotene solid dispersion prepared by hot-melt technology improves its solubility in water.

ß-Carotene is a member of the carotenoid family and is a red-orange pigment abundantly present in many vegetables and fruits. As an antioxidant, it eliminates excessive reactive oxygen species generated in the body. Accordingly, it has potential to be used in the pharmaceutical, food, and cosmetic industries. ß-Carotene has a very low water solubility and low bioavailability; thus, there is a need to develop techniques to overcome these issues. In this study, we aimed to enhance the water solubility of ß-carotene by using hot-melt technology, a type of solid dispersions technology. When preparing ß-carotene solid dispersion using this method, suitable conditions for the emulsifiers and mixing ratios were investigated using water solubility as an index. Setting the weight ratio of ß-carotene:polyvinylpyrrolidone:sucrose fatty acid ester to 10%:70%:20% resulted in the poorly-water soluble ß-carotene showing improved water solubility (120 µg/mL). The physicochemical properties of the optimized ß-carotene solid dispersion were analyzed using field emission scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction. The solid dispersion was found to have an amorphous structure. The improved solubility observed for ß-carotene in the solid dispersions developed in this work may make these dispersions useful as additives in foods or in nutraceutical formulations.

Synthesis of organic-inorganic hybrid bicelles-lipid bilayer nanodiscs encompassed by siloxane surfaces.

Well-defined hybrid nanodiscs were produced by employing bicelle formation of a binary lipid mixture in water. The resulting nanoparticles have a lipid bilayer coated with ceramic layers, which are formed by the sol-gel reaction among the alkoxysilyl headgroups of the hybrid lipid. The hybrid bicelles displayed significant morphological stability against dry environments and surfactant addition, in stark contrast to conventional phospholipid bicelles.