Browsing by Subject "Microcrystalline cellulose"

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  • Dong, Yujiao; Paukkonen, Heli; Fang, Wenwen; Kontturi, Eero; Laaksonen, Timo; Laaksonen, Paivi (2018)
    Drug release from a new type of matrix material consisting of partially fibrillated microcrystalline cellulose was investigated. A mechanical treatment of novel AaltoCell T cellulose microcrystals caused partial opening of the nanofibrillary structure of the cellulose particles and entanglement of individual particles led into formation of an elastic network of microcrystalline cellulose. The rheological properties of the stable hydrogel-like materials were characterised by shear rheometry. Model compounds metronidazole and lysozyme were successfully employed in drug release experiments carried out by delignified (bleached) and lignin-containing matrices. The viscosity as well as the lignin-content played a role in the release dynamics of the drugs. Microcrystalline AaltoCell T was proven as high-performing material for diffusion controlled release of the chosen model compounds and can be seen as a safe and economical alternative for novel matrix materials such as nanocellulose or cellulose derivatives.
  • Tanner, Timo; Antikainen, Osmo; Ehlers, Henrik; Blanco, David; Yliruusi, Jouko (2018)
    The compression physics of powders must be considered when developing a suitable tablet formulation. In the present study, the gravitation-based high-velocity method was utilized to analyze mechanical properties of eight common pharmaceutical excipients: two grades of lactose, anhydrous glucose, anhydrous calcium hydrogen phosphate, three grades of microcrystalline cellulose and starch. Samples were compressed five times consecutively with varying pressure and speed so that Setup A produced higher pressure and longer contact time than Setup B. The important parameters obtained from samples were porosity profiles, compaction pressure, contact time, internal energy change and the amount of elastic recovery. All acquired data was only based on distance-time profile of the compression event. Lactose and glucose fragmented effectively while calcium hydrogen phosphate remained in rearrangement phase, due to its hardness and insufficient pressure applied. Microcrystalline cellulose samples showed plastic behaviour and starch was most elastic of all the samples. By utilizing the method, examined excipients could be categorized according to their compression behaviour in an accurate and cost-efficient manner.
  • Pulkkinen, Elli (Helsingin yliopisto, 2022)
    There is a growing demand for new, environmentally sustainable, clean label food additives driven by consumers’ desire for healthier and sensorially appealing food products. The aim of this thesis is to study a novel, “clean label” food additive called fibrillated microcrystalline cellulose (fMCC) in the formation of emulsions, elucidate its stabilization mechanism, as well as emulsion storage stability at room temperature over time. To this aim, oil-in-water emulsions with fMCC and vegetable oil were formed via mechanical treatment. It was found that the oil droplets anchor on the surface of the fibrils attached to the microcrystalline cellulose. After homogenization fMCC formed large, entangled aggregates that were located in the continuous phase of the emulsion. This increased the viscosity of the emulsion, which contributed to the stability of the system. During storage, further aggregation was observed. High oil content emulsions exhibit some coalescence, while oil droplets in low oil content emulsions remained unchanged. In this thesis, it was shown that fMCC can be used as a suitable and environmentally sustainable ingredient for emulsion formation and stabilization, with the added benefit of increasing the fiber content of many processed foods and thus increasing their nutritional value.
  • Blanco, David; Antikainen, Osmo; Räikkönen, Heikki; Pei Ting Mah; Healy, Anne Marie; Juppo, Anne Mari; Yliruusi, Jouko (2020)
    Powder flowability plays an important role in die filling during tablet manufacturing. The present study introduces a novel small-scale measuring technique for powder flow. Based on image analysis, the flow was defined depending on the variation of luminous intensity and the movement of powder inside the measurement cuvette. Using quantities around 100 mg it was possible to characterize a wide range of common pharmaceutical powders, especially in distinguishing subtle differences in flow caused by minor changes in samples characteristics. The method was compared with powder rheometry, which is widely used in the pharmaceutical literature, and showed a significant improvement in predicting the success of pharmaceutical minitablet manufacture (d = 5 mm). Tablet weight variation (RSD) was defined as the most efficient way to assess relevant powder flow behaviour in tablet production when using the novel device. The proposed method was distinguished from others by its ability to classify different grades of microcrystalline cellulose in the die-filling process. Subsequently, eight common pharmaceutical powders, both excipients and APIs, were properly ranked as a function of flowability based on their physical properties. The method showed a high repeatability, with a relative standard deviation not more than 10%.
  • Tanner, Timo; Antikainen, Osmo; Ehlers, Henrik; Yliruusi, Jouko (2017)
    With modern tableting machines large amounts of tablets are produced with high output. Consequently, methods to examine powder compression in a high-velocity setting are in demand. In the present study, a novel gravitation-based method was developed to examine powder compression. A steel bar is dropped on a punch to compress microcrystalline cellulose and starch samples inside the die. The distance of the bar is being read by a high-accuracy laser displacement sensor which provides a reliable distance-time plot for the bar movement. In-die height and density of the compact can be seen directly from this data, which can be examined further to obtain information on velocity, acceleration and energy distribution during compression. The energy consumed in compact formation could also be seen. Despite the high vertical compression speed, the method was proven to be cost-efficient, accurate and reproducible. (C) 2017 Elsevier B.V. All rights reserved.
  • Vainio, Mika (Helsingfors universitet, 2016)
    The literature review dealed with fat replacers in frankfurters. Manufacturing, properties and usages of microcrystalline cellulose were described. Also other fat replacers that are at the moment in use are described, such as hydrocolloids and proteins from vegetable. The literature review also described different methods that have been used to measure properties of frankfurters. The aim of the experimental work was to find out the influence of two different types of microcrystalline cellulose, Vivapur® 105(i) and Arbocel® M80(ii), on the properties of frankfurters, and can they been used as a fat replacer. Three different concentrations of microcrystalline cellulose (MCC) (1 %, 3 % and 5 %) Were studied and compared to the control sample. Measured properties of frankfurters were pH, water holding, cooking loss, firmness and bite force. Also amount of free water was measured with NMR. Although adding MCC decreased pH of frankfurter closer to the isoelectric point, it did not affect as lowering water holding. Both MCC(i) and MCC(ii) increased significantly (p<0,05) firmness of the frankfurters when measuring was made with warm samples, excluding MCC(i) 3 % concentration. Effect was not as visible in the measurements of bite force.