Nanospray Drying as a Novel Tool to Improve Technological Properties of Soy Isoflavone Extracts

Pharmacological evidences have correlated a low incidence of osteoporosis, breast cancer, cardiovascular disease, and colon cancer in Asian populations, high consumers of soya, to the properties of soy isoflavones, more specifically to daidzein and genistein. However, in spite of the potent biological activity, their poor water solubility has a strong negative effect on bioavailability. In this study, an innovative technique, nano spray drying, was used to obtain nanoparticles loaded with a soybean dry extract while carboxymethyl cellulose was used as the excipient. The optimization of the process conditions allowed for the manufacturing of stable nanoparticles with a mean size of around 650 nm, a narrow size distribution, and a high encapsulation efficiency (between 78 % and 89 %). The presence of carboxymethyl cellulose was able to stabilize the isoflavone extract and enhance its affinity with aqueous media, strongly increasing its permeation through biological membranes up to 4.5-fold higher than pure soy isoflavone extract raw material and twice its homologous minispray-dried formulation. These results are very useful for the administration of the extract, either topically or orally, suggesting that the isoflanones extract nanoparticulate powder obtained by nano spray drying has great potential to enhance extract bioavailability and could be used as an ingredient to be enclosed in dietary supplements and nutraceutical and cosmeceutical products.