Processing pharmaceutical grade microcrystalline cellulose from groundnut husk: Extraction methods and characterization

Microcrystalline cellulose (MCC) is an important ingredient in pharmaceutical, food, cosmetic and other industries. In this work, MCC was prepared from the alpha cellulose content of groundnut husk, a renewable natural resource that has no industrial utilization yet. The effects of pulping methods (sodium hydroxide and multistage pulping) and varying bleaching time on yield and amorphous properties of obtained alpha cellulose were examined. The prepared MCC (groundnut husk-MCC) was characterized using scanning electron microscopy (SEM), infrared spectroscopy (FTIR), X-ray powder diffractometer (X-RPD), differential scanning calorimetry (DSC) and compared with commercial-grade MCC. The results showed that complete pulping was achieved only by the use of the multistage pulping method and its yield was 15%. It was also found that the duration of bleaching affected the polymeric form of the processed alpha cellulose and hence, it is suggested that X-ray diffraction analysis should form an in-process check in the production of cellulose to ensure batch-to-batch consistency and performance. It was concluded that GH-MCC compared favourably with the commercial-grade MCC as well as conform to official specifications for MCC in the British Pharmacopoeia.