Phosphoric Acid-Mediated Depolymerization and Decrystallization of α-Cellulose Obtained from Corn Cob: Preparation of Low Crystallinity Cellulose and Some Physicochemical Properties

Purpose: Low crystallinity celluloses (LCC) are materials that have a substantially reduced degree of crystallinity, typically ranging between 15 and 45%. It is useful as an excipient in preparation of tablets and confectionery products. The aim of this work was to obtain from α-cellulose content of corn cob, a low crystallinity cellulose (LCC-CC), and study its physical properties as well as evaluation of its potential as tablet excipient. Methods: α- cellulose (AC-CC) obtained from corn cob by a delignification process, was depolymerized with 85% phosphoric acid to yield LCC-CC product, whose physical properties were compared with those of AC-CC. Results: The yield of AC-CC and LCC-CC were 14 and 11 %, respectively. The physical properties indicated a good level of purity of the cellulose materials as they conform to British Pharmacopoeia specifications. The flow indices, however, showed that these materials flowed poorly. Conclusion: It was concluded that LCC-CC is a potential disintegrant and filler-diluent, in pharmaceutical tableting. Keywords: Low crystallinity cellulose, α-cellulose, physical properties, corn cob. > Tropical Journal of Pharmaceutical Research Vol. 4 (2) 2005: pp. 509-51