Rheology and microstructure of concentrated microcrystalline cellulose (MCC)/1-allyl-3-methylimidazolium chloride (AmimCl)/water mixtures

Soft Matter ◽  
2018 ◽  
Vol 14 (37) ◽  
pp. 7615-7624 ◽  
Author(s):  
Ashna Rajeev ◽  
Abhijit P. Deshpande ◽  
Madivala G. Basavaraj

Water added to a solution of microcrystalline cellulose (MCC) in 1-allyl-3-methylimidazolium chloride (AmimCl) reduces the solvent quality and causes significant changes in the flow properties and microstructure due to restructuring and aggregation of cellulose molecules.

Author(s):  
Kusuma P. ◽  
Syukri Y ◽  
Sholehuddin F. ◽  
Fazzri N. ◽  
Romdhonah . ◽  
...  

The most efficient tablet processing method is direct compression. For this method, the filler-binder can be made by coprocessing via spray drying method. The purpose of this study was to investigate the effect of spray dried co-processing on microcrystalline cellulose (MCC) PH 101, lactose and Kollidon® K 30 as well as to define the optimum proportions. Spray dried MCC PH 101, lactose, and Kollidon® K 30 were varied in 13 different mixture design proportions to obtain compact, free-flowing filler-binder co-processed excipients (CPE). Compactibility and flow properties became the key parameters to determine the optimum proportions of CPE that would be compared to their physical mixtures. The result showed that the optimum proportion of CPE had better compactibility and flow properties than the physical mixtures. The optimum CPE, consisting of only MCC PH 101 and Kollidon® K 30 without lactose, that were characterized using infrared spectrophotometer, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscope (SEM) indicated no chemical change therein. Therefore, this study showed that spray dried MCC PH 101, lactose and Kollidon® K 30 could be one of the filler-binder alternatives for direct compression process.


Cellulose ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Beatrice Swensson ◽  
Anette Larsson ◽  
Merima Hasani

Abstract In order to further understand the role of the cation when dissolving cellulose in aqueous solutions of hydroxide bases, different bases were combined in solution. Up to 5 wt.% of microcrystalline cellulose was dissolved using a combination of NaOH and the organic base tetramethylammonium hydroxide (TMAH) in water at low temperatures. Thermoscans of solutions containing both NaOH(aq) and TMAH(aq) indicated that cellulose interaction with TMAH seems to be favoured over NaOH. Dynamic rheology measurements of the solutions revealed that combining the two bases delayed gelation significantly when compared to cellulose dissolved in NaOH(aq) or TMAH(aq) alone. Intrinsic viscosity of cellulose in the combined NaOH- and TMAH(aq) solutions was slightly higher than that of the single-base solutions, indicating a slight increase in solvent quality. This shows that combining bases may lead to synergies that improve solvent stability without requiring the use of other additives. Graphic abstract


2019 ◽  
pp. 304-310
Author(s):  
Gordana Svonja-Parezanovic ◽  
Mladena Lalic-Popovic ◽  
Svetlana Golocorbin-Kon ◽  
Nemanja Todorovic ◽  
Nebojsa Pavlovic ◽  
...  

The powder flow plays an important role in the manufacture of dosage form such as direct compression tablets. The objective of this research was to investigate the individual and interaction effects of magnesium stearate (MgSt) (Merck Ltd., Germany) as lubricant and sodium starch glycolate (SSG) (Primojel?) as superdesintegrator on powder flowability. Powder formulations were prepared by mixing different concentration of MgSt (0.25% and 5%) and SSG (0.5% and 4%) with microcrystalline cellulose (MCC) (Vivapur?101) or spray-dried lactose (LAC) (Super Tab 21AN) as diluents. Eight powder formulations were prepared using as filler LAC and MCC, as superdesintegrator SSG and as lubricant MgSt in ratios as follows: P1 (LAC : 0.5% SSG : 0.25% MgSt); P2 (LAC : 4% SSG : 5% MgSt); P3 (LAC : 0.5% SSG : 5% MgSt); P4 (LAC : 4% SSG : 5% MgSt); P5 (MCC : 0.5% SSG : 0.25% MgSt); P6 (MCC : 4% SSG : 5% MgSt); P7 (MCC : 0.5% SSG : 5% MgSt); P8 (MCC : 4% SSG : 0.25% MgSt). The powder formulations were evaluated using indirect methods of flowability evaluation according to 9th European Pharmacopoeia: measurement of tapped and bulk density (Ph.Eur.9, 2.9.34) and angle of repose (Ph.Eur. 2.9.36). Also, compressibility index, Hausner?s ratio were calculated. A full factorial design with three factors at two levels and response surface methodology were applied to evaluate the influence of various concentrations of MgSt and SSG on powder flowability. The results indicate that flow properties improved with decrease of SSG content and with increase of MgSt content. Magnesium stearate in powder formulations with microcrystalline cellulose has a greater influence on the improvement of the flow properties than powder formulations with spray-dried lactose.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 342 ◽  
Author(s):  
Birte Martin-Bertelsen ◽  
Erika Andersson ◽  
Tobias Köhnke ◽  
Artur Hedlund ◽  
Lars Stigsson ◽  
...  

Cotton production is reaching a global limit, leading to a growing demand for bio-based textile fibers produced by other means. Textile fibers based on regenerated cellulose from wood holds great potential, but in order to produce fibers, the components need to be dissolved in suitable solvents. Furthermore, the dissolution process of cellulose is not yet fully understood. In this study, we investigated the dissolution state of microcrystalline cellulose in aqueous NaOH by using primarily scattering methods. Contrary to previous findings, this study indicated that cellulose concentrations of up to 2 wt % are completely molecularly dissolved in 8 wt % NaOH. Scattering data furthermore revealed the presence of semi-flexible cylinders with stiff segments. In order to improve the dissolution capability of NaOH, the effects of different additives have been of interest. In this study, scattering data indicated that the addition of ZnO decreased the formation of aggregates, while the addition of PEG did not improve the dissolution properties significantly, although preliminary NMR data did suggest a weak attraction between PEG and cellulose. Overall, this study sheds further light on the dissolution of cellulose in NaOH and highlights the use of scattering methods to assess solvent quality.


2011 ◽  
Vol 212 (1) ◽  
pp. 253-257 ◽  
Author(s):  
Limin Shi ◽  
Sayantan Chattoraj ◽  
Changquan Calvin Sun

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