Preparation andIn VitroRelease of Drug-Loaded Microparticles for Oral Delivery Using Wholegrain Sorghum Kafirin Protein

Esther T L Lau,Kathryn J Steadman,Peter J Halley,Zhongxiang Fang,Deirdre Mikkelsen,Roger A Stanley,Stuart K Johnson

doi:10.1155/2015/343647

Abstract

Kafirin microparticles have been proposed as an oral nutraceutical and drug delivery system. This study investigates microparticles formed with kafirin extracted from white and raw versus cooked red sorghum grains as an oral delivery system. Targeted delivery to the colon would be beneficial for medication such as prednisolone, which is used in the management of inflammatory bowel disease. Therefore, prednisolone was loaded into microparticles of kafirin from the different sources using phase separation. Differences were observed in the protein content,in vitroprotein digestibility, and protein electrophoretic profile of the various sources of sorghum grains, kafirin extracts, and kafirin microparticles. For all of the formulations, the majority of the loaded prednisolone was not released inin vitroconditions simulating the upper gastrointestinal tract, indicating that most of the encapsulated drug could reach the target area of the lower gastrointestinal tract. This suggests that these kafirin microparticles may have potential as a colon-targeted nutraceutical and drug delivery system.

Highlights

Kafirin is a storage protein extracted from sorghum grain and shares many similarities with zein, the storage protein extracted from maize [1]
Prednisolone was successfully loaded into microparticles formulated using kafirin from different sorghum wholegrain sources
Based on formulations prepared in the present study, the amount of microparticles required to obtain a clinically relevant dose of prednisolone is realistic and feasible for an oral delivery system

Summary

Introduction

Kafirin is a storage protein extracted from sorghum grain and shares many similarities with zein, the storage protein extracted from maize (e.g., an analogous pattern of peptide subunits) [1]. Kafirin microparticles loaded with condensed tannins and catechins have previously been investigated as an oral delivery system [5] Problems such as dose-limiting side effects restrict current pharmacological management options for colonic conditions such as inflammatory bowel disease (IBD). This is often due to the inability to effectively and efficiently deliver pharmacological therapy to the affected areas of the lower GIT. Corticosteroids such as prednisolone are used in the management of IBD and are drugs that would benefit from

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