175: A Nanoplatform of Dual-Modified Starch-Based Bilayer Oral Dispersible Film for Immune-Enhancing Quercetin-Zinc Complex Delivery

Introduction

Although oral dispersible films (ODFs) have attracted attention to a novel delivery system of nutraceutical active compounds, there are major challenges of ODF such as disintegration and low efficiency. This study investigated the dual-modified starch bilayer ODF by exploring the effect of the nanoencapsulation of the quercetin metal complex on the structure and antioxidant functionality, as well as the release profile in the oral system.

Due to the functional limitations of native starch, it has been modified to reduce its crystallinity and enhance solubility. Moreover, the combined film matrix of dual-modified starch and poly(vinyl alcohol) could enhance mucoadhesion and provide a high loading capacity of nutrients. Meanwhile, to enhance the functionality and stability of quercetin, metal chelation with zinc and nanoencapsulation of quercetin was used. Therefore, the aim of this study was to confirm the feasibility of the development of a new type of oral delivery nanoplatform.

Methods

Corn starch was modified via hydroxypropylation and then spray-dried with ι-carrageenan to enhance the water solubility. Quercetin was chelated with zinc acetate and nanoencapsulated via antisolvent nanoprecipitation using β-cyclodextrin. Furthermore, the hydrogel was copolymerized using locust bean gum grafted with acrylic acid-acrylamide to mimic the oral mucosa and mucin. The film was characterized by mechanical strength, disintegration time, antioxidant activity, and mucoadhesion. The released quercetin-zinc complex was quantified and fitted to mathematical models.

Results

The folding endurance and elongation were enhanced via dual modification due to the reduced crystallinity of starch. The disintegration test of films revealed that the disintegration time was within 30 seconds, which is suitable for the fast-dissolving ODF with minimized discomfort and rapid absorption. The results demonstrate that metal chelation enhanced the antioxidant capacity of ODF and nanoencapsulation exhibited a rapid release behavior.

Significance

Zinc-based quercetin metal chelation provides higher antioxidant activity. Moreover, nanoencapsulation of the metal chelation complex would be a novel approach to the delivery of nutrients. This result could be helpful for the standardization of analysis of mucoadhesion using an innovative copolymerized hydrogel and release behavior of fast-dissolving ODFs. A bilayer of ODF would achieve a high dose of nutrients with both high solubility and mucoadhesion.

Authors: Jimin Kang, Hong-geon Song, Jaejoon Han