Preparation of Spray-Dried Soy Isoflavone-Loaded Gelatin Microspheres for Enhancement of Dissolution: Formulation, Characterization and in Vitro Evaluation.

Gean Panizzon,Celso Nakamura,Tânia Ueda-Nakamura,Fernanda Bueno,Benedito Dias Filho

doi:10.3390/pharmaceutics6040599

Abstract

The most bioactive soy isoflavones (SI), daidzein (DAI) and genistein (GEN) have poor water solubility, which reduces their bioavailability and health benefits and limits their use in industry. The goal of this study was to develop and characterize a new gelatin matrix to microencapsulate DAI and GEN from soy extract (SE) by spray drying, in order to obtain solid dispersions to overcome solubility problems and to allow controlled release. The influences of 1:2 (MP2) and 1:3 (MP3) SE/polymer ratios on the solid state, yield, morphology, encapsulation efficiency, particle size distribution, release kinetics and cumulative release were evaluated. Analyses showed integral microparticles and high drug content. MP3 and MP2 yield were 43.6% and 55.9%, respectively, with similar mean size (p > 0.05), respectively. X-ray diffraction revealed the amorphous solid state of SE. In vitro release tests showed that dissolution was drastically increased. The results indicated that SE microencapsulation might offer a good system to control SI release, as an alternative to improve bioavailability and industrial applications.

Highlights

Soy isoflavones (SI) are major diphenolic secondary metabolites found in soybeans [Glycine max (L.) Merr.] [1]
The analytical method for extraction and quantification of soy isoflavones (SI) reported in this study was validated according to the guidelines established by the ICH (International Conference on the Harmonization of Technical Requirements for the Registration of Pharmaceuticals for Human Use) [29] and by Brazilian regulation RE 899/2003 of the National Health Surveillance Agency (ANVISA) [30]
The intra- and inter-day measurements showed that the method is accurate

Summary

Introduction

Soy isoflavones (SI) are major diphenolic secondary metabolites found in soybeans [Glycine max (L.) Merr.] [1]. Almost all isoflavones in soybeans exist in the form of glycosides [3,4] Interest in these substances is growing, since nutrition research and epidemiological studies in recent decades have suggested that a high dietary intake of soy-containing foods is associated with beneficial biological functions. Despite the structural diversity found in soybeans, the aglycones DAI and GEN have the most potent and wide-ranging biological activities among SI [6] These biological activities include the ability to protect against hormone-dependent cancers, increase bone density [7], decrease the risk of heart diseases [8], prevent breast and prostate cancers [9,10], and decrease thrombogenicity and low-density lipoprotein (LDL) levels [11,12]. The poor water solubility of these bioactive compounds negatively affects membrane permeation, reducing their bioavailability [6] and limiting their use for nutraceuticals, functional foods, cosmetics, and pharmaceutical purposes [16,17]

Objectives

Results

Conclusion