Addition Of Liquid Binder Research Articles

Incomplete cocrystalization of ibuprofen and nicotinamide and its interplay with formation of ibuprofen dimer and/or nicotinamide dimer: A thermodynamic analysis based on DFT data.

Cocrystallization of ibuprofen and nicotinamide in hot melt extrusion process has been subject of many studies addressing low ibuprofen bioavailability. However, it is observed that the process of cocrystal formation of ibuprofen and nicotinamide might be incomplete. We hypothesized that formation of dimers of ibuprofen-ibuprofen or dimers nicotinamide- nicotinamide might be the cause of such poor cocrystalization process by altering the phase behaviour of the mixture. This paper addresses the molecular thermodynamics of mixtures of ibuprofen and nicotinamide, with special focus on the possibility of formation of these dimers and their corresponding interplay with mixture phase behaviour. For this purpose, density functional theory calculations are used to calculate electron donor-acceptor sizes on each molecule and accordingly possible dimers of each molecule are analysed. The free energies and phase diagram are determined for (1) when a dimer is formed or (2) no dimer is formed, over a wide operating temperature range of 273.15K-390K. The binding and solvation energies are calculated to identify/rank dimers. Calculations showed that formation of dimers requires an energy input which can be accessible noting to the external heating in hot melt extrusion process. The calculated solvation energies of the dimers suggest that addition of liquid binder (water) can mitigate the risk of dimer formations. Addition of proper binder/excipient is an easy route to compensate such dimer formation and to engineer ibuprofen and nicotinamide cocrystallization behaviour.

Microstructure of micro-crystalline cellulose based granules produced by high-shear wet granulation with long wet-massing time

Design and scale-up of batch high-shear granulation is complicated by the interplay of granule nucleation, growth, and breakage and their non-linear dependence on liquid binder addition rate and granulation time. In an earlier paper, we demonstrated that during extended wet massing times, granule growth and breakage rates become equal (pseudo-steady-state granulation), and the ultimate granule size distribution depends only on agitation intensity and granulating fluid level. This significantly simplifies scale-up. The granule size distributions produced in these long granulation times were quite narrow compared to those produced in more typical granulation times.This work provides additional characterization of the granules produced in “steady-state” granulation. We observe an interesting microstructural change in granules comprised of microcrystalline cellulose and lactose. During extended wet massing, these granules evolve from typical agglomerates comprised of primary MCC and lactose particles to a bi-continuous structure with a skeleton of porous cellulose with pores filled with the remaining formulation components. The soluble components can be removed from the pores by dissolution, leaving the porous MCC skeleton. The dependence of the microstructure on wet massing time, liquid level, and MCC content is reported.

Optimization of the binder addition methods for bulk Y-Ba-Cu-O superconductors

Abstract Recent studies have revealed that an addition of binder such as acrylic is effective in reducing cracking during the preparation processes of the precursors and thus in promoting the grain growth of good quality bulk superconductors. However, when the distribution of binder is not uniform, some defects are introduced in the precursors and thereby the grain growth is inhibited. At present, the optimum conditions for mixing binders and precursor superconducting raw materials are not yet established. In this work, we have studied the effects of the liquid binder addition on the superconducting properties and the grain growth behavior of bulk Y-Ba-Cu-O superconductors about 40 mm in diameter produced with the top-seed melt-growth process. We have found that optimized binder additions contribute to the consolidation of the bulk precursor and further to the grain growth of single-grain bulk superconductors.

Effect of high shear granulation process parameters on the production of granola cereal aggregates

Granola is an aggregated cereal food product which can be used as a breakfast cereal or snack comprised of ingredients such as cereals, nuts and honey. A high shear mixer granulator was used to produce granola in a wet granulation process followed by oven drying. The aim was to investigate the effect of granulation parameters; impeller speed, binder addition rate and wet massing time on key granola physical properties. Experiments were carried out at impeller speeds of 150, 200 and 300 rpm during binder addition and wet massing. Binder addition rates of 0.22, 0.33 and 0.65 g s −1 and wet massing periods of 6, 9 and 12 min were applied respectively. The granola was then dried on an oven at 160 °C for 10 min. Granule size distribution and granule strength were measured using a digital image analyser and texture analyser respectively. Regarding the process variables, the agglomeration behaviour was found to vary greatly with impeller speed. Granules formed at low impeller speed were found to have low apparent density. The results enabled the optimal ranges of impeller speeds, liquid binder addition rate and the wet massing time to be established for this system, thereby aiding the manufacturing process in terms of controllability and reproducibility. ► High shear mixer granulator was used to produce granola breakfast cereal. ► Effect of impeller speed, binder addition rate and wet massing time investigated. ► Impeller rotational speed is the single most important process parameter. ► Highest impeller speed and lowest binder addition rate gave highest hardness and crispness.

Enhancement of mechanical strength in Y–Ba–Cu–O bulk superconductor through liquid binder addition

We have studied the effects of the liquid binder (polyvinyl alcohol) addition (0–10wt%) on the mechanical properties of the green compacts and also on the superconducting properties of bulk Y–Ba–Cu–O superconductors of 20mm diameter produced with the top-seeded melt growth (TSMG) process. The mechanical properties of the green compacts with binder addition were characterized with the compression tests, which revealed that mechanical strength increased dramatically with increasing the amount of the binder addition. The binder-added green compacts were then subjected to the TSMG process and oxygen annealing. The trapped field measurements showed that we could produce single-grain bulk Y–Ba–Cu–O samples with binder additions up to 8wt% without any deterioration in the superconducting properties.

Crack reduction in a large bulk Y–Ba–Cu–O superconductor through liquid binder addition

We have studied the effects of the incorporation of polyvinyl acetate (PVA) aqueous solution on the formability of the precursor Y–Ba–Cu–O samples with the aim of improving the mechanical properties of large bulk RE–Ba–Cu–O superconductors that are susceptible to cracking. We found that the green compacts of YBa2Cu3Oy and Y2BaCuO5 powders added with PVA liquid binder exhibited good mechanical properties and could be mechanically machined without defects. We could successfully drill 17 holes of 1mm diameter into the green compact. The drilled samples were subjected to melt-processing and oxygen annealing, and further characterized with microstructural observations and magnetization measurements. The results showed that liquid binder addition was very effective in reducing cracks for large melt-processed Y–Ba–Cu–O superconductors.

The kinetics of the granulation process: Right from the early stages

In this study, experimentation and modelling were carried out to understand the granulation process. This work assesses whether there is a significant difference in the aggregation rate of the wet granulation process between the very early stages and later stages of high shear granulation. Measurements of the size distribution and binder content from the beginning of the process, just after liquid binder addition, were carried out. A population balance model based on two different kernels, the Equi Kinetic Energy (EKE) kernel and two-dimensional population balance equations with a Size Independent (SI) kernel, was applied to the high shear granulation process. It was concluded that the population balance equations with SI kernel best described the aggregation in the high shear granulation process. The value of aggregation rate constant in the early stages is smaller than aggregation kernel in the later stages.