(318c) Microcrystalline Cellulose from Soybean Hull As an Excipient for Solid Dosage Forms: Powder Characterization and Tableting Properties

Soybean is one of the most valuable crops being planted and harvested worldwide. The USA is the leading country in soy production (around 124 million metric tons in 2018-19), followed by Brazil, Argentine, China, India, Paraguay, and Canada. The main products of the soy industry are soy oil and soy protein with many food, feed, and cosmetic applications. The seed coat of soybeans, known as soybean hull (SBH), is the major by-product of the soybean industry and represents 8-10% of the whole composition of the grain. Despite the large amount generated, SBHs have received minimal attention as low-cost raw materials, and their applications are limited to animal feed and dietary fiber, while most of them are still left to waste. Therefore, there is a strong need to create higher value-added products from this agro-industrial waste.

Microcrystalline cellulose (MCC) is one of the most widely used binders in the formulation of oral suspensions and lotions, oral tablets, and capsules due to its chemical purity, non-toxicity, biodegradability, superior disintegrating property, and greater flowability. According to a market study conducted by Future Market Insights (FMI), the market for MCC will grow at a steady annual rate of 4.7%, topping US$ 818 million in 2028. Among all the markets mentioned above, the pharmaceutical industry dominates the global MCC demand with about 40 percent market share, most of which can be attributed to its role as the direct compression (DC) binder in oral tablet manufacturing.

In this study, we have produced SBH-based MCC as an alternative to wood-based commercial MCC (Avicel®). The processing stages include acid pretreatment followed by filtering and washing, alkali pulping, and chlorine dioxide bleaching. The filtrate from the acid treatment stage can be used in producing biopolymer-based (rich in protein and pectin) coatings and films. This integrated approach will produce a by-product while decreasing the amount of effluent produced. SBH-based powders were tested and compared with Avicel MCC powders for their thermal properties (TGA), structural and morphological properties (XRD and SEM), chemical composition (HPLC), density, and flowability (tap density tester, pycnometer, and angle of repose), and surface area (BET). The powders were then incorporated as the main component (60%) of excipient-only tablets comprised of lactose, sodium starch glycolate, and magnesium stearate. The quality and properties of the produced SBH MCC tablets (hardness, tensile strength, and disintegration) were tested and compared to the Avicel MCC tablets. Based on the results, we concluded that the SBH-based MCC can be a potential alternative for industrial scale tablet production.