1,721,026 research outputs found
Microwave assisted drying of cellulose derivative (HPMC) granular solids
Full text linkDrying constitutes a critical unit operation in the manufacturing of pharmaceutical powders and their associated
products. In this work, the drying processes of cellulose derivative (hydroxypropyl methyl cellulose,
HPMC) granules were investigated. Granules of HPMC powders were produced by a wet granulation process
using a hydro-alcoholic solution as binder phase, then they were dried with different drying methods based
on traditional (by convective heating) and innovative (by microwave heating) techniques. To compare drying
kinetics, experimental data were fitted by Lewis equation obtaining drying coefficients, and time/temperature
process parameters were investigated. Microwave assisted drying showed reduced process times and, under
someconditions, it allowed no drastic process temperatures. Since granular solids have a great relevance in pharmaceutical
solid dosage formpreparations, novelmethods of drying with better performances appeared an issue
of great interest for industry
SHELL-CORE PARTICLES PRODUCTION BY COAXIAL DOUBLE CHANNEL DEVICE
No full textMicroencapsulation is a process providing the formation of thin coating around core structures, at solid, liquid or gas state, to stabilize them, to mask undesired taste or to modify release properties (Venkatesan et al., 2009). New approaches to microencapsulation process, especially in pharmaceutical products manufacturing, are continuously investigated with the aim to answer to several needs, basically avoiding inactivation of active molecules, reducing residual level of organic solvent and especially assuring the usefulness at industrial scale (Benita, 2006). For example, the development of shell-core systems by a coaxial atomizer may offer several additional advantages in drug delivery, such as delayed or pulsatile release and removal of drug ‘‘burst’’. Moreover, the coupling of ultrasonic source with coaxial atomization device could be of great interest thanks to ultrasonic atomization advantages: drops velocity 1-10% larger than of a hydraulic or air-atomizing nozzle, lower mechanical stress caused by vibration, avoided deactivation of bioactive substances and operation at low energy levels (Rajan, 2001).
In this work shell-core particles were produced using a novel apparatus composed by a coaxial double channel device connected to a ultrasonic generator. Shell-core beads were produced to observe encapsulation process (with ultrasounds switched off) and preliminary steps towards shell-core microparticles production were performed
An engineering approach to biomedical sciences: advanced strategies in drug delivery systems production
Full text linkDevelopment and optimization of novel production techniques for drug delivery systems are fundamental steps in the “from the bench to the bedside” process which is the base of translational medicine. In particular, in the current scenery where the need for reducing energy consumption, emissions, wastes and risks drives the development of sustainable processes, new pharmaceutical manufacturing does not constitute an exception. In this paper, concepts of process intensification are presented and their transposition in drug delivery systems production is discussed. Moreover, some examples on intensified techniques, for drug microencapsulation and granules drying, are reporte
Droplet size prediction in the production of drug delivery microsystems by ultrasonic atomization
Full text linkMicroencapsulation processes of drugs or other functional molecules are of great interest in pharmaceutical production fields. Ultrasonic assisted atomization is a new technique to produce microencapsulated systems by mechanical approach. It seems to offer several advantages (low level of mechanical stress in materials, reduced energy request, reduced apparatuses size) with respect to more conventional techniques. In this paper the groundwork of atomization is briefly introduced and correlations to predict droplet size starting from process parameters and material properties are presented
Ultrasonic energy in liposome production: Process modelling and size calculation
No full textThe use of liposomes in several fields of biotechnology, as well as in pharmaceutical and food sciences is continuously increasing. Liposomes can be used as carriers for drugs and other active molecules. Among other characteristics, one of the main features relevant to their target applications is the liposome size. The size of liposomes, which is determined during the production process, decreases due to the addition of energy. The energy is used to break the lipid bilayer into smaller pieces, then these pieces close themselves in spherical structures. In this work, the mechanisms of rupture of the lipid bilayer and the formation of spheres were modelled, accounting for how the energy, supplied by ultrasonic radiation, is stored within the layers, as the elastic energy due to the curvature and as the tension energy due to the edge, and to account for the kinetics of the bending phenomenon. An algorithm to solve the model equations was designed and the relative calculation code was written. A dedicated preparation protocol, which involves active periods during which the energy is supplied and passive periods during which the energy supply is set to zero, was defined and applied. The model predictions compare well with the experimental results, by using the energy supply rate and the time constant as fitting parameters. Working with liposomes of different sizes as the starting point of the experiments, the key parameter is the ratio between the energy supply rate and the initial surface area
Intensifying the microencapsulation process: Ultrasonic atomization as an innovative approach
Full text linkIn this review, new approaches to the microencapsulation processes, widely used in the manufacturing of
pharmaceutical products, are discussed focusing the attention on the emerging ultrasonic atomization
technique. Fundamentals and novel aspects are presented, and advantages of ultrasonic atomization in
terms of intensification and low energy requests are emphasized
Liposoluble vitamin encapsulation in shell–core microparticles produced by ultrasonic atomization and microwave stabilization
No full textEncapsulation may protect unstable, fat soluble vitamins such as vitamin D2 (ergocalciferol). However, encapsulation by the solvent extraction and/or evaporation techniques can require toxic organic solvents, which greatly increase processing costs. The objective of this study was to evaluate the effect on ergocalciferol encapsulation by a combination of the ionic gelation method with the ultrasonic atomization and microwave drying. Optimization of manufacturing parameters included the addition of pluronic-F127 to the core solution at 1.5% w/w to increase the encapsulation efficiency to nearly 92%, greatly improving performance compared to Tween 80 at 0.5% w/w. Microwave treatment at 230 W promoted the recovery of 100% of the ergocalciferol and reduced drying times to about 30 min, while 690 W degraded 40% of the D2. In contrast, the conventional heating degraded 17% of the ergocalciferol during 12 h of processing. By all the applied methods, microparticles were produced with similar gastoresistance properties of less than 10% release at pH of 1.0, to nearly 100% release at pH of 6.8 and 240 min of dissolution. Analysis showed limited ergocalciferol degradation after 5 months of storage
Liposomal SUVs preparation by ultrasonic energy: a new approach based on a conventional technique
No full textIn this work preparation and characterization of liposomal
small unilamellar vesicles based on thin-film hydration
method are presented. In particular, the attention is focused
on vesicles size and active molecule load achievable by a
protocol based on sonication duty cycle to form loaded
SUVs from large vesicles
Single-Pot Semicontinuous Bench Scale Apparatus To Produce Microparticles
Full text linkThis work presents both the design of a novel process to produce microparticles with a shell−core structure and a
bench scale apparatus purposely realized. The developed process was designed to respond to mandatory needs of process
intensification. It involved the coupling of two emergent technologies: atomization assisted by ultrasonic energy and microwave
heating. The former was used to atomize polymeric solutions; the latter was applied to stabilize the produced droplets by drying.
Both operations were performed in the same vessel with the aim to have a single-pot process chamber and were carried out by a
semicontinuous procedure. Basic design criteria and advantages of the ultrasonic−microwave coupled operations in the realized
apparatus are presented and discussed. Results of testing and of operating runs to produce shell−core microparticles are also
reported, emphasizing the main features of the produced particles
Simultaneous measurement of Theophylline and Cellulose Acetate Phthalate in Phosphate Buffer by UV analysis
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