Characterization Of Microcrystalline Cellulose Research Articles

Characterization of Microcrystalline Cellulose after Pretreatment with Low Concentrations of Ionic Liquid-H2O for a Pyrolysis Process

Microcrystalline cellulose (MCC) samples pretreated by ionic liquid (ILs)-H2O mixtures were studied for application in a pyrolysis process. A 1-ethyl-3-methylimidazolium methanesulfonate [Emim][MeSO3]-H2O mixture with solid acid catalyst Nafion®NR50 was used in the pretreatment process. A lower amount of hydrogen bonding between neighboring pretreated MCC chains resulted from a less ordered cellulose structure, leading to lower crystallinity, decreased molecular weight and reduced thermal stability. The pyrolysis result showed that the yields of char were lower, the average reaction rate increased, and the DTG peak temperature decreased relative to the untreated MCC. The amount and concentration of the hydrogen gas obtained from the pyrolysis of sample 90(20) (4.00 mmol/g-sample) was higher than that obtained from the pyrolysis of the MCC (3.26 mmol/g-sample). This study explores MCC (pretreated by ionic liquid-H2O mixtures) with a recyclable solid acid catalyst under varying pretreatment conditions, as a potential raw feed material, to be applied in the pyrolysis process.

Isolation and Characterization of Microcrystalline Cellulose from Distillers Grains

Isolation and Characterization of Microcrystalline Cellulose from Distillers Grains

Preparation and Characterization of Microcrystalline Cellulose (MCC) by Acid Hydrolysis Using Microwave Assisted Method from Cotton Wool

SummaryThe microcrystalline cellulose (MCC) was extracted by microwave assisted from cotton wool. The effects of sulfuric acid concentration, time and temperature on the yield were investigated by a single factor experiments and the preparation condition were optimized using 23 factorial design and analyzed by statistical test. The obtained MCC were characterized using particle size analyzer, FT‐IR and XRD. The results showed that the main parameter in order of increasing effects on the MCC yield were time, temperature and acid concentration. The optimum condition was found at acid concentration 55% (w/w), time 1 minute and temperature 30°C. The range of particle size at that condition was from 0.052 μm to 353.078 μm, the yield was 78.67% (w/w) and the crystallinity index was 53.16%. Moreover the crystal structure transformed from cellulose I to cellulose II. The crystal structure of cellulose II was obtained without mercerization and ionic liquid treatments.

Extraction and characterization of microcrystalline cellulose from fodder grass; Setaria glauca (L) P. Beauv, and its potential as a drug delivery vehicle for isoniazid, a first line antituberculosis drug

Microcrystalline cellulose (MCC) is generally produced through acid hydrolysis of woody plants and agro sources. MCC synthesized from a common wild grass Setaria glauca (L) P. Beauv was characterized to explore the possibility of application in pharmaceutical industry especially as a drug delivery vehicle. The SEM, TGA, XRD and FTIR investigations of the prepared MCC reveal that the 5–30μm long, non aggregated MCC rods have high crystallinity index of 80% and were stable at 286°C. The preliminary investigation of the MCC incorporated micro beads containing isoniazid, one of the first line drugs for treatment of tuberculosis was carried out in the simulated intestinal fluid (SIF). The MCC incorporated micro beads with isoniazid drug load showed sustained release upto 24h with release of 0.521μg of isoniazid equivalent drug in the SIF system. No cytotoxicity of the MCC was observed in the haemolytic assay. The MCC also showed good antioxidant activity. Thus, the study reveals that the MCC can be prepared from an inexpensive and abundant grass species. The MCC have properties advantageous for application in the pharmaceutical industry and may be explored further in drug delivery research.

Isolation and characterization of microcrystalline cellulose from oil palm biomass residue

In this work, we successfully isolated microcrystalline cellulose (MCC) from oil palm empty fruit bunch (OPEFB) fiber-total chlorine free (TCF) pulp using acid hydrolysis method. TCF pulp bleaching carried out using an oxygen–ozone–hydrogen peroxide bleaching sequence. Fourier transform infrared (FT-IR) spectroscopy indicates that acid hydrolysis does not affect the chemical structure of the cellulosic fragments. The morphology of the hydrolyzed MCC was investigated using scanning electron microscopy (SEM), showing a compact structure and a rough surface. Furthermore, atomic force microscopy (AFM) image of the surface indicates the presence of spherical features. X-ray diffraction (XRD) shows that the MCC produced is a cellulose-I polymorph, with 87% crystallinity. The MCC obtained from OPEFB-pulp is shown to have a good thermal stability. The potential for a range of applications such as green nano biocomposites reinforced with this form of MCC and pharmaceutical tableting material is discussed.

A novel combined pretreatment of ball milling and microwave irradiation for enhancing enzymatic hydrolysis of microcrystalline cellulose

Microcrystalline cellulose (MCC) was performed as a mode substrate to investigate its potential ability of bioconversion in a novel combined pretreatment of ball milling (BM) and/or microwave irradiation (MWI). The variation of structure characteristics of MCC before/after pretreatment were investigated, including crystallinity index (CrI), size of crystal (SC), specific surface area (SSA) and degree of polymerization (DP). Their correlation with the rate of enzymatic hydrolysis was differentiated by an optimized equation which indicated the rate of hydrolysis was much more sensitive to CrI than SSA and DP. To achieve the same or higher glucose yield of BM for 3h and 6h, BM for 1h with MWI for 20min could save 54.8% and 77.40% energy consumption, respectively. Moreover, chemicals were not required in this process. It is concluded that the combination of BM and short time MWI is an environment-friendly, economical and effective approach to treat biomass.

Comparing microcrystalline with spherical nanocrystalline cellulose from waste cotton fabrics

Microcrystalline cellulose (MCC) and spherical nanocrystalline cellulose (SNCC) were successfully prepared from waste cotton fabrics through acid hydrolysis. The comparative analysis of the morphology and structure between the obtained MCC and SNCC was carried out. The SNCC suspension exhibited higher stability than the MCC suspension. Transmission electron microscopy in combination with atomic force microscopy showed that the cellulose nanospheres with average size of 35 nm were achieved, while the average particle size of MCC was 49 μm. The MCC and SNCC had similar functional groups and crystalline structure as confirmed by Fourier transform infrared spectroscopy and X-ray diffraction analysis, respectively. Viscometric average molecular weight measurement and thermo gravimetric analysis indicated that the degree of polymerization and thermal stability of SNCC was lower than that of MCC. These results should improve understanding of the characteristics of MCC and SNCC derived from waste cotton fabrics and lead to many new applications.

The change in characteristics of microcrystalline cellulose during wet granulation using a high-shear mixer.

The objective of this study was to investigate the mechanism of hard granule formation and to demonstrate the applicability of X-ray diffraction methods for studying the polymeric pharmaceutical excipients. Using a high-shear mixer, microcrystalline cellulose (MCC) was granulated with water as the granulating liquid. The hardness of the MCC granules increased with granulation time and the amount of water added. The specific surface area measured by the N2 adsorption method was reduced during the process. Crystallite size of cellulose, calculated by Scherrer's equation adapted for wide angle X-ray diffraction method, decreased with granulation time and with increasing amounts of water added. Debye plots for X-ray small scattering patterns suggested that the average magnitude of the continuous solid region in MCC granules became significantly greater, whereas the specific surface area of the MCC granules, calculated from Debye plots, became smaller in comparison with that of intact MCC. These findings suggested that the long-chain structures in MCC were disrupted, resulting in smaller units with shorter chain lengths due to the strong shear force of the impeller. These smaller units then form a network within the granules. Thus, MCC granules are strengthened with longer granulation time and greater amounts of water, resulting in a more intricate network. The change in MCC chain length and physical structure can be experimentally detected using the small-angle X-ray scattering and wide-angle powder X-ray diffraction methods.

Characterization of microcrystalline cellulose and cellulose long fiber modified by iron salt

Microcrystalline cellulose (MCC) and cellulose long fiber (CLF) were treated with iron (Fe) based salt and the samples were characterized to study the coordination complexes formed between cellulose and iron. The Fe-modified MCC and CLF were characterized by spectroscopic, thermal and morphological methods. MCC and CLF were oxidized and further treated with iron (Fe) based salt in a high pH medium to form coordination complexes. Both MCC and CLF were then analyzed using Scanning electron microscopy (SEM) to examine their surface morphology. The results have shown that there was no major change in morphology for MCC and CLF upon modification. The functional groups formed by modifying cellulose by iron salt were investigated using FTIR-ATR spectroscopy and the nature of the coordination bonds formed between cellulose and Fe ions were examined by X-ray photo electron spectroscopy (XPS). The results agree that coordination bonds were formed between de-protonated and or oxidized hydroxyl group and Fe ions. Powder XRD (PXRD) was resourceful to compare the crystallinity of unmodified and Fe-modified samples of MCC and CLF. Thermal stability of modified cellulose was studied using thermo gravimetric analysis (TGA). The results showed that there was an increase in percentage of residual mass and higher thermal stability for the Fe-modified MCC and CLF compared to unmodified samples due to the presence of iron.

Influence of UV pretreatment on the abies wood catalytic delignification in the medium “acetic acid–hydrogen peroxide–TiO2”

Some regularities of abies-wood oxidative delignification by acetic acid–hydrogen peroxide mixture under the action of suspended TiO2 catalyst and UV pretreatment of wood pulp were studied. The combined action of TiO2 catalyst and of UV-pretreatment of abies-wood allow to produce at optimal conditions of the delignification process the chemically pure cellulose containing no residual lignin. The major characteristics of cellulose product obtained from abies-wood correspond to the characteristics of microcrystalline cellulose.

An efficient method-development strategy for quantitative chemical imaging using terahertz pulse spectroscopy

The purpose of our research was to investigate efficient procedures for generating multivariate prediction vectors for quantitative chemical analysis of solid dosage forms using terahertz pulse imaging (TPI) reflection spectroscopy. A set of calibration development and validation tablet samples was created following a ternary mixture of anhydrous theophylline, lactose monohydrate, and microcrystalline cellulose (MCC). Spectral images of one side of each tablet were acquired over the range of 8 cm−1 to 60 cm−1. Calibration models were generated by partial least-squares (PLS) type II regression of the TPI spectra and by generating a pure-component projection (PCP) basis set using net analyte signal (NAS) processing. Following generation of the calibration vectors, the performance of both methods at predicting the concentration of theophylline, lactose, and MCC was compared using the validation spectra and by generating chemical images from samples with known composition patterns. Sensitivity was observed for the PLS calibration over the range of all constituents for both the calibration and the validation datasets; however, some of the calibration statistics indicate that PLS overfits the spectra. Multicomponent prediction images verified the spatial and composition fidelity of the system. The NAS-PCP calibration procedure yielded accurate linear predictions of theophylline and lactose, whereas the results for MCC prediction were poor. The poor sensitivity for MCC is assumed to be related to the relative lack of phonon absorption bands, which concurs with the characterization of MCC as being semi-crystalline. The results of this study demonstrate the use of TPI reflection spectroscopy and efficient NAS-PCP for the quantitative analysis of crystalline pharmaceutical materials.

A study of the effects of the physical characteristics of microcrystalline cellulose on performance in extrusion spheronization.

Physical characterization and extrusion-spheronization profiles of 11 microcrystalline cellulose (MCC) grades were performed. Correlation between the physical characteristics and extrusion spheronization behavior and pellet quality was performed to determine critical MCC characteristics that influence the water requirement and spheronization water sensitivity for extrusion-spheronization. Extrusion spheronization of MCC-lactose at varying water contents was performed to determine water requirement, spheronization water sensitivity, and the effect of increasing water content on some pellet qualities (pellet flow rate, friability, bulk, and tapped densities) of each MCC grade. MCC physical properties and tapping characteristics were assessed. Correlation between MCC physical properties and its spheronization behavior parameters was performed. MCC characteristics, such as powder particle size, size distribution, and porosity, were found to have little influence on the extrusion-spheronization process. However, significant correlation was found between void volumes or packing properties of MCC and the water requirement for extrusion-spheronization and pellet qualities. A new insight into the action of MCC as a spheronizing aid was discovered. MCC void volume and packing properties play an important role in determining water retention and release during extrusion-spheronization.

The Effect of Wax on Compaction of Microcrystalline Cellulose Beads Made by Extrusion and Spheronization

The effect of wax on the deformation behavior and compression characteristics of microcrystalline cellulose (Avicel® PH-101) and acetaminophen (APAP) beads is described. Beads of Avicel PH-101 and APAP formulations were prepared using extrusion and spheronization technology. A waxy material, glyceryl behenate, N.F. (Compritol ®), was added to the formulations in amounts ranging from 10% to 70% of total solid weight. Beads with a selected particle size range of 16-30 mesh were compressed with an instrumented single punch Manesty F press utilizing a 7/16-in. flat-faced tooling set. Compaction profiles were generated for the tablets to evaluate the effect of wax on the densification of beads containing wax. Beads made without wax (the control formulation) required greater compression forces to form cohesive tablets. As the amount of wax in the bead formulation was increased, the beads become more plastic and compressible. The Heckel equation which relates densification to compression pressure was used to evaluate the deformation mechanisms of the bead formulations. The analysis shows that as the level of wax in the bead formulation is increased, the yield pressure decreases, indicating that the beads densify by a plastic deformation mechanism.

Low frequency dielectric spectroscopy characterization of microcrystalline cellulose, tablets and paper

Cellulose fibres and particles in the form of powder, tablets and paper sheets have been investigated by very low frequency dielectric spectroscopy using a novel form of dielectric cell, in which two planar electrodes have been mounted in fixed positions at right angles. The broad pattern of response obtained from the samples is independent of the structural form of the cellulose sample, a loss peak in the 0.1–100 Hz range, and at lower frequencies a dispersion process which is dominated by an imperfect charge transport. Moisture has a significant influence on the rate of charge transport. In dry samples the dipolar loss peak was not evident but as the moisture content increased it appeared. Using a humidity normalizing technique the dielectric response for microcrystalline cellulose has been characterized over the equivalent of 14 decades in frequency. It has also been shown that there is a linear response between the capacitance and the density of microcrystalline cellulose samples. The consolidation of powder into tablets is discussed with respect of the observations of changes in capacitance, loss peak frequency and imperfect charge transport efficiency. Furthermore it was found possible to investigate differences between the dipolar relaxation rate “in” and “out” of the plane of paper in the stack. The relaxation time for dipoles “out” of the paper plane is 7 to 8 times longer than for dipoles “in” the paper plane.

Drug release mechanism from a microcrystalline cellulose pellet system.

A common form of modified release is the encapsulation of specially formulated or coated pellets. An important first step in the development of a multiparticulate coated dosage form is to characterize the uncoated pellet. In earlier work, an uncoated pellet system developed in these laboratories and prepared from microcrystalline cellulose (MCC) was investigated and found to exhibit both the physical characteristics of an inert matrix and varying degrees of in vitro modified release. The use and characterization of MCC as a spheronization matrix material forms the basis for this formulation study. The drug release mechanism has been verified by varying selected formulation factors and evaluating the resulting pellets according to the relationship developed by T. Higuchi for granular inert matrices. In all cases, this MCC pellet system adhered to the theoretical relationships and the drug release mechanism can, therefore, be classified as an inert matrix.

Evaluation of a New Fine Particulate Cellulose as a Direct Compression Tablet Aid

AbstractA new grade of α-cellulose, composed of a mixture of amorphous and crystalline cellulose was evaluated in this preliminary study for its potential as an inert direct compression tablet vehicle. Though not a micro-crystalline cellulose, this product, identified as EGC, possesses the tabletting characteristics of micro-crystalline cellulose. It is prepared by a physicochemical procedure that does not require severe heat or acid treatment but yields a product which is white, fine granular, free-flowing and highly compressible.