Pharmaceutics and Pharmaceutical Technology- Scholarly Publications

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Browsing Pharmaceutics and Pharmaceutical Technology- Scholarly Publications by Subject "Agricultural residue"

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    Open Access
    Comparative studies on the pharmacopoeial and flow properties of powdered celluloses extracted from maize cob using different chemical procedures
    (2012) Azubuike, C.P.; Odulaja, J.; Okhamafe, A.O.
    In this work a comparative study on different methods of extraction of α-cellulose from agricultural residue- maize (Zea mays) cob was carried out. α-Celluloses were extracted from the agricultural residue using various chemical procedures based on:- nitric acid/ sodium hydroxide, sodium hydroxide, organsolvent and ionic liquid (IL) [1-butyl-3-methylimidazolium chloride ([C4mim]Cl)]. The chemical composition and flow properties of the extracted α-celluloses were estimated using the known standard methods. The α-celluloses extracted from the agricultural residue using nitric acid/ sodium hydroxide and sodium hydroxide methods, respectively, were relatively free from other lignocellulosic contents (lignin content < 0.70% and hemicelluloses < 1.30%) compared to the organosolvent method (lignin content 1.54-4.03 % and hemicelluloses 4.50-10.05%), and IL method (lignin content 3.45% and hemicelluloses 12.50%). Apart from the α-cellulose obtained with IL, others showed poor flow properties. The results show that the IL method is a promising process for the extraction of cellulose with improved flow characteristics from maize cobs, however, the cellulose method obtained with this method failed pharmacopoeial requirement in terms of purity. Since the ionic liquids can be almost 100% recycled, this might be a low cost, fast, simple and environmentally friendly chemical procedure that can increase significantly the competitiveness of α-cellulose extraction if the purity of the obtained cellulose can be improved upon.
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    Open Access
    Physicochemical properties of maize cob cellulose powders reconstituted from ionic liquid solution
    (Springer, 2012) Azubuike, C.P.; Rodriquez, H.; Okhamafe, A.O.; Rogers, R.
    Suitable a-cellulose and cellulose II powders for use in the pharmaceutical industry can be derived from maize cob. a-Cellulose was extracted from an agricultural residue (maize cobs) using a nondissolving method based on inorganic substances. Modification of this a-cellulose was carried out by its dissolution in the ionic liquid 1-butyl 3-methylimidazolium chloride ([C4mim]Cl), and subsequent regeneration by addition of either water or acetone at room temperature, or of boiling water. X-ray diffraction and infrared spectroscopy results showed that the regenerated celluloses had lower crystallinity, and proved that the treatment with [C4mim]Cl led to the conversion of the crystalline structure of a-cellulose from cellulose I to cellulose II. Thermogravimetric analysis and differential scanning calorimetry data showed quite similar thermal behavior for all cellulose samples, although with somewhat lower stability for the regenerated celluloses, as expected. The comparison of physicochemical properties of the regenerated celluloses and the native cellulose mainly suggests that the regenerated ones might have better flow properties. For some of the characterizations carried out, it was generally observed that the sample regenerated with boiling water had more similar characteristics to the a-cellulose sample, evidencing an influence of the regeneration strategy on the resulting powder after the ionic liquid treatment
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    Open Access
    Physicochemical, spectroscopic and thermal properties of microcrystalline cellulose derived from corn cobs
    (Springer, 2012) Azubuike, C.P.; Okhamafe, A.O.
    Background: Low-cost and suitable microcrystalline cellulose powders for use in the pharmaceutical industry can be derived from agricultural residues. Most commercial microcrystalline cellulose powders are produced from dissolving pulp obtained from expensive hard woods using concentrated acids. α-Cellulose was extracted from an agricultural residue (corn cob) using a non-dissolving method. The spectroscopic, thermal and physicochemical properties of the derived α-cellulose and microcrystalline cellulose powders were compared with AvicelW PH 101 (Fluka, New South Wales, Australia), a commercial brand of microcrystalline cellulose (MCCA), using standard methods. Results: X-ray diffraction showed that the microcrystalline cellulose samples obtained from maize cobs had diffraction pattern characteristics of both cellulose I and cellulose II, whereas MCCA had that of cellulose I; however, all the microcrystalline cellulose samples had similar crystallinity index (CI) values. Infrared spectroscopy results showed that the microcrystalline cellulose samples had comparable CI values and molecular structure. Thermogravimetric analysis and differential scanning calorimetry data showed quite similar thermal behaviour for all cellulose samples. Comparison of physicochemical properties of the microcrystalline cellulose powders obtained from maize cob and MCCA mainly suggests that all the celluloses have similar flow and compression properties. Conclusions: For almost all of the characterizations carried out, it was observed that the microcrystalline cellulose powders obtained from corn cob had similar characteristics to the MCCA, showing that it can be a good low-cost alternative to the expensive commercial brand.
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    Open Access
    Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells.
    (International Pharmaceutical Excipients Council of the America, 2012) Azubuike, C.P.; Odulaja, J.; Okhamafe, A.O.
    α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow) properties were investigated. α–Cellulose (GCN) was extracted from groundnut shell (an agricultural waste product) using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN). The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA), using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α- cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA) might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.