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

Some Physical Characteristics of Microcrystalline Cellulose Obtained from Raw Cotton of Cochlospermum planchonii

Purpose: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. This study aimed at evaluating the physical characteristics of microcrystalline cellulose (CP-MCC), obtained from the raw cotton of Cochlospermum planchonii. Methods: CP-MCC was obtained from the raw cotton by a two-stage sodium hydroxide treatment process followed by sodium hypochlorite bleaching and acid hydrolysis. It was examined for its physicochemical and powder properties. The powder properties of CP-MCC were compared to those of the well-known commercial microcrystalline cellulose grade, Avicel PH 101. Results: The extraction yield of CP-MCC was approximately 21%. The cellulose material was composed of irregularly shaped fibrous cellulose particles with a moisture content of 7.2% and total ash of 0.12%. The true density was 1.38. The flow indices showed that CP-MCC has poor flow. The hydration, swelling and moisture sorption capacities were 4.7, 83.3 and 22%, respectively. Conclusion: The cellulose product, CP-MCC, obtained from the raw cotton of Cochlospermum planchonii conformed to the official specifications in the British Pharmacopoeia (2004). The flow properties of a powder are critical in direct compression tableting; consequently, for the materials to be used for this purpose, it would require the addition of a glidant. Furthermore, the swelling parameters indicate that CP-MCC would be a better disintegrant than Avicel PH 101. Keywords: Cochlospermum planchonii, microcrystalline cellulose, physical characteristics, pharmacopoeial requirements> Tropical Journal of Pharmaceutical Research Vol. 4 (2) 2005: pp. 501-50

A Comparative Evaluation of the Flow and Compaction Characteristics of a-Cellulose obtained from Waste Paper

Purpose: Alpha-cellulose obtained as pulp from fibrous plant materials has found use in the pharmaceutical industry as a disintegrant and direct compression diluent. The aim of this study was to evaluate the suitability of α-cellulose obtained from waste paper as a direct compression excipient. Method: The flow and compaction characteristics of α-cellulose (ACP) obtained from waste paper, in comparison with Avicel PH 101, using the Kawakita and Heckel models were evaluated. Result: The results indicate that the flow properties of these materials could not be predicted accurately using the Kawakita model. A comparison of compression behaviour and compactibility of the two powders showed Avicel PH 101 to be a slightly better binder. Conclusion: It was concluded that ACP material could find use as a potential dry binder and direct compression diluent in tableting as the binding properties were comparable to those of Avicel PH 101. . Keywords: Alpha-cellulose, microcrystalline cellulose, flow and compaction characteristics, direct compression diluent. > Tropical Journal of Pharmaceutical Research Vol. 6 (1) 2007: pp. 645-65

Properties of microcrystalline cellulose obtained from coconut (Cocos nucifera) husk

This study was aimed at developing a pharmaceutical grade microcrystalline cellulose from coconut fruit husk fibre as a tablet excipient. The microcrystalline cellulose coded CH-MCC, was obtained from coconut (Cocos nucifera) fruit husk fibre by a two-stage sodium hydroxide delignification process followed by sodium hypochlorite bleaching and acid hydrolysis. CH-MCC was examined for its physicochemical and powder properties. The powder properties of CH-MCC were compared to those of best commercial microcrystalline cellulose grade, Avicel PH 101. The extraction yield of CH-MCC was approximately 19%. The cellulose material was composed of irregularly shaped fibrous cellulose particle with a moisture content of 6.2%. The true density was 1.53. The flow indices showed that CH-MCC flowed poorly. The hydration and swelling capacities were 3.15 and 48.6% respectively. The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose. Keywords: Coconut fruit fibre, microcrystalline cellulose, powder properties Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: pp. 12-1

Microcrystalline cellulose obtained from

This study was aimed at developing pharmaceutical grade microcrystalline cellulose from Chasmanthera dependens stem phloem fibres as a tablet excipient. The microcrystalline cellulose coded CD-MCC, was obtained from the phloem fibres by a two-stage sodium hydroxide delignification process followed by sodium hypochlorite bleaching and acid hydrolysis. CD-MCC was examined for its physicochemical and powder properties. The powder properties of CD-MCC were compared to those of best commercial microcrystalline cellulose grade, Avicel PH 101. The extraction yield of CD-MCC was about 17%. The cellulose material was composed of irregularly shaped fibrous cellulose particle with a moisture content of 4.8%. The true density was 1.66. The flow indices showed that CD-MCC flowed poorly. The hydration and swelling capacities were 2.19 and 41.9% respectively. The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose Keywords: Chasmanthera dependens; Microcrystalline cellulose, Extraction; Characterization Journal of Pharmacy and Bioresources Vol. 3 (2) 2006: pp. 70-7

Formulation and Evaluation of Bi-layer Tablet of Metoclopramide Hydrochloride and Ibuprofen

The aim of this study was to prepare bi-layer tablet of Metoclopramide Hydrochloride (MTH) and Ibuprofen (IB) for the effective treatment of migraine. MTH and IB were formulated as immediate and sustained release layer respectively. MTH was formulated as immediate release layer by using various disintegrants like Ac-Di-Sol, Polyplasdone XL, Explotab, Agar and Gellan Gum. Treated form of gellan gum and agar was prepared and compared for their disintegrant efficiency with other disintegrants. IB was formulated as sustained release layer using hydrophilic matrix (hydroxypropylmethylcellulose [HPMC K4M]). The effect of concentration of hydrophilic matrix (HPMC K4M), binder (polyvinylpyrollidone [PVP K30]) and buffer (sodium bicarbonate) on IB release was studied. The dissolution study of sustained release layer showed that an increasing amount of HPMC or PVP K30 results in reduced IB release. The inclusion of buffer (sodium bicarbonate) enhanced the release of IB from sustained release layer. The rational for formulation of bi-layer tablet of these two drugs in combination was (1) MTH increases the absorption of acidic non-steroidal anti-inflammatory drug (NSAID) by increasing gastric motility. So sequential release of MTH (as immediate release) and IB (as sustained release) was suitable for treatment of migraine. (2) MTH was degraded when prolonged contact with acidic NSAID. Bi-layer tablet was suitable for preventing direct contact of these two drugs and thus to maximize the efficacy of combination of two drugs for migraine