Powder Flow Properties Research Articles

Enhancing vitamin D3 – iron blends via twin-screw dry granulation: Microstructural properties and cellular uptake analysis of vitamin D3

The aim of this study was to develop vitamin D3 (VD3) and iron (Fe) blended granules using Neusilin® US2 as an excipient. A central composite design of experiments was used for the continuous manufacturing process, considering VD3 and iron as independent variables and the bulk density, flow index, oil holding capacity, and color difference as response variables. The addition of VD3 had a significant effect on the powder flow properties. The X-ray diffraction and Scanning electron microscopy-energy dispersive X-ray analysis validated the presence of VD3 and Fe in the granules, whereas the variations in porosity and roughness were demonstrated by tomography and atomic force microscopy, respectively. The in vitro cellular uptake profile confirmed the absorption of VD3 in the breast cancer cell line MCF-7 with apparent apoptosis. These results could help in scaling up the process from laboratory to pilot scale in twin-screw granulation and boost the intervention of VitD3/iron deficiencies.

Optimising Spread-Layer Quality in Powder Additive Manufacturing: Assessing Packing Fraction and Segregation Tendency

Powder bed fusion (PBF), a subset of additive manufacturing methods, is well known for its promise in the production of fully functional artefacts with high densities. The quality of the powder bed, commonly referred to as powder spreading, is a crucial determinant of the final quality of the produced artefact in the PBF process. Therefore, it is critical that we examine the factors that impact the powder spreading, notably the powder bed quality. This study utilised a newly developed testing apparatus, designed specifically for examining the quality of powder beds. The objective was to analyse the influence of various factors, including the recoater shape, recoater gap size, and the different powder flow properties, on the powder bed relative packing fraction. Additionally, the study aimed to assess the variation in the particle size and shape across the build plate. The results indicated that all of the variables examined had an impact on the relative packing fraction, as well as the size and shape variations observed across the build plate.

Correction to: Effect of gas permeation and consolidation stress evolution on powder flow properties in the gas pressurization process

Correction to: Effect of gas permeation and consolidation stress evolution on powder flow properties in the gas pressurization process

Moisture sorption isotherms and storage study of spray-dried probiotic finger millet milk powder

Moisture sorption isotherms provide information on the interaction between food and the storage environment. The sorption isotherms of spray-dried probiotic finger millet milk powder were studied with different salt solutions at different temperatures (25–45 °C). The storage behavior and quality parameters of the powder were characterized at different storage conditions and packaging materials. The isotherm data were tested with empirical models. The Peleg model was best fitted for the sorption isotherm study at 25 °C with the highest adj. R2 (0.999) confirming type III isotherm. The powder flow properties were in an acceptable range. The powder stored at 4 °C and 25 °C exhibited 56 and 35 days of shelf life, respectively, with acceptable probiotic viability of 6 log CFU/g. A laminated aluminum pouch was best suited as a packaging material to store the probiotic powder. The results could be adopted for the packaging and bulk storage of probiotic finger millet milk powder.

Study of diminutive granules as feed powders for manufacturability of high drug load minitablets

The maximal amount of drug contained in a minitablet is limited. To reduce the total number of minitablets in a single dose, high drug load minitablets can be prepared from high drug load feed powders by various pharmaceutical processing techniques. Few researchers have however examined the influence of pharmaceutical processing techniques on the properties of high drug load feed powders, and consequently the manufacturability of high drug load minitablets. In this study, silicification of the high drug load physical mix feed powders alone did not yield satisfactory quality attributes and compaction parameters to produce good quality minitablets. The abrasive nature of fumed silica increased ejection force and damage to the compaction tools. Granulation of fine paracetamol powder was crucial for the preparation of good quality high drug load minitablets. The diminutive granules had superior powder packing and flow properties for homogenous and consistent filling of the small die cavities when preparing minitablets. Compared to the physical mix feed powders for direct compression, the granules which possessed higher plasticity, lower rearrangement and elastic energies, yielded better quality minitablets with high tensile strength and rapid disintegration time. High shear granulation demonstrated greater process robustness than fluid bed granulation, with less discernment on the quality attributes of feed powder. It could proceed without fumed silica, with the high shear forces reducing interparticulate cohesivity. An in–depth understanding on the properties of high drug load feed powders with inherently poor compactability and poor flowability is important for the manufacturability of high drug load minitablets.

Effect of gas permeation and consolidation stress evolution on powder flow properties in the gas pressurization process

Effect of gas permeation and consolidation stress evolution on powder flow properties in the gas pressurization process

Study on fine powder discharged from hoppers modified with insert

The use of inserts in the hopper provides a reliable way to improve the quality of powder flow. In this work, glass beads, fluidized catalytic cracking catalyst (FCC), lignite and polyvinyl chloride (PVC) were used as experimental materials and the flow properties of powders were characterized by the FT4 powder rheometer and the PT-X powder tester. Discharge experiments on a Perspex hopper at a laboratory scale are presented in this paper, comparing the flow characteristics of fine powders discharged from a plain hopper and from hoppers modified with the use of inserts of different geometries. Effects of insert and powder properties on powder flow rate are discussed. A mechanism model is developed to describe the hindering effect to the discharge consequent to the powder expansion at the hopper outlet. Mechanisms of insert on powder flow are analyzed. It is demonstrated that the higher flow rates of the hopper operating with a solid insert are due to the anticipated expansion of the material generated by the presence of the insert. The hopper with a hollow insert shows a flow sequence and the values for the powder flow rates are averaged values between two regimes. Based on understanding above mechanisms, powder flow rates for plain hopper and hoppers modified with insert are successfully predicted.

Electrical capacitance tomography-based estimation of slug flow parameters in horizontally aligned pneumatic conveyors

Pneumatic conveying is a widely applied technique for the transportation of powders. Dense phase conveying such as slug flow is the preferable operating condition of such transport systems. Advantages are the reduced energy and conveying gas consumption and reduced material wear. The design and the operation of dense phase conveyors is a challenging task due to complex flow dynamics and the lack of reliable flow meters, which are crucial for process control. In this work the capabilities of electrical capacitance tomography (ECT) for slug flow parameter estimation are analysed. The estimation of flow parameters is addressed and demonstrated by means of laboratory experiments. Amongst other parameters it is shown that mass concentration distributions as well as particle velocity fields can be obtained from tomographic image reconstruction results, which are substantial parameters for potential mass flow metering. Additionally, the proposed estimation techniques are applied to signals provided by an ECT system, which is installed within a large-scale pneumatic conveyor of an industrial process plant. It is observed that also Geldart group A powders with Archimedes numbers in the scale of Ar≈1e0 are conveyable in slug-like structures which can be separated by stationary or non-stationary layers. Furthermore, various slug flow properties of powders with Ar>1e2 reported in literature are confirmed but also deviating properties are observed, leading to novel insights into horizontal dense phase flow processes of powders with Ar≈1e0. The results demonstrated in this work are pointing out the capabilities of ECT for flow analyses, which are enabling further insights into flow mechanisms and future developments of flow meters for dense phase flow processes.

Effect of Turntable Rotation Rate on Drying Kinetics and Functional Properties of Lemon Peel during Microwave Drying

The aim of this study is to investigate the effect of the rotational rate of the turntable on drying kinetics of lemon peels and some functional and flow properties of lemon peel powders. Lemon peels were dried by microwave drying using different rates of rotation (0, 6.5, 9.5, and 12.5 rpm) at different microwave power levels (180W, 300W, 450W and 600W), and dried by oven drying and freeze-drying methods. Drying time was shortened by 72- 95% by microwave drying compared to oven drying. Microwave drying with rotation provided 5.6-23.8% reduction in drying time of peels compared to drying without rotation. Effect of rotation rate on drying time of lemon peels depended on the microwave power level. Page model provided lower SSE, RMSE, and higher R2 values within 5 different thin layer models. The effective moisture diffusivity value, ranging between 1.7x10-8 m2 s -1 -7.6x10-8 m2 s -1, was higher during microwave drying with rotation. The activation energy ranged between 21.3-22.7 W/g. Microwave drying provided higher bulk density, similar or lower water holding capacity and oil retention capacity values compared to freeze drying and oven drying. Freeze dried lemon peel powder had the lowest bulk density due to its porous structure. Microwave drying without rotation and the highest power level caused lower bulk density. At higher power levels, influence of turntable rotation on water holding capacity was more notable. Microwave drying technique can be used as alternative drying techniques to obtain high quality dried lemon peel powder if appropriate processing conditions are selected.

Dry granulation of vitamin D3 and iron in corn starch matrix: Powder flow and structural properties

In this work, a twin-screw dry granulation (TSDG) was adopted to produce vitamin D3 (VD3) and iron blended dry granules using corn starch as an excipient. Response surface methodology was applied to determine the effect of the formulation compositions (VD3 and iron) on granule properties [tapped bulk density, oil holding capacity, and volumetric mean particle size (Dv50)]. Results indicated that the model fitted well, and responses, in particular flow properties, were significantly affected by the composition. The Dv50 was only influenced by the addition of VD3. The flow properties were characterized by the Carr index and Hausner ratio, which indicated very poor flow of the granules. Scanning electron microscopy with energy dispersive spectroscopy confirm the presence and distribution of Fe++ and VD3 in the granules. Overall, TSDG was proven to be a simple alternative method for the preparation of dry granules of VD3 and iron in a blend.

BOX-BEHNKEN DESIGN FOR OPTIMIZATION OF FORMULATION VARIABLES FOR CONTROLLED RELEASE GASTRORETENTIVE TABLET OF VERAPAMIL HYDROCHLORIDE

Objective: To develop a Verapamil hydrochloride controlled release gastro-retentive (CRGR) tablet for once-daily dosing using the response surface Box-Behnken Design (BBD) approach for the improvement of bioavailability and reduction in dosing frequency to overcome the issues related to the conventional tablet formulation. Methods: For the optimization, 33Box-Behnken design was used. The independent variables were selected, the amount of Compritol 888 ATO (A), HPMC K15M (B), and Sodium bicarbonate (C). The dependent variables were Cumulative % drug release in 1.5 h (Q1.5), 8 h (Q8), 24 H (Q24) and floating lag time (FLT). Flow properties of pre-compressed powder, physical characteristics, drug content, floating lag time, total floating time and in vitro dissolution study of all formulation were assessed. In vitro dissolution study of optimized formulation that was prepared experimentally was performed and compared with predicted data obtained from the software. Drug release kinetics of the optimized formulation was also assessed to know the mechanism of drug release from the CRGR tablets. Results: Responses of experimental runs were found as Q1.5: 12.78-33.62 (%), Q8: 43.03-64 (%), Q24: 78.77 to 103.57 (%) and floating lag time as 3.01 min to 5.08 min. The predicted optimized formula with the highest desirability value of 0.963 containing amount 126.030 mg, 160.00 mg and 80.955 mg of Compritol 888 ATO, HPMC K15M and Sodium biarbonate respectively was prepared and evaluated. The experimental values from optimized formulation were obtained as Q1.5: 23.397%, Q8; 57.744%, Q24: 97.150% and FLT: 3.12 min. Predicted and experimental results were found comparable for all the responses. The release data from the optimized formulation were best fitted in the Higuchi (r2 = 0.999) and the Korsmeyer-Peppas ((r2 = 0.998, n=0.54) model. The in vitro drug release studies indicated that the Verapamil hydrochloride gastroretentive tablet releases the drug in controlled manner for 24 h. Conclusion: This study found that using Box-Behnken Design with the response and variable relation, it is possible to achieve an optimum formulation with desirable characteristics. This study also established the suitability of Compritol 888 ATO-HPMC K15M combination with Sodium bicarbonate to increase the gastric residence time tablet formulation had once-daily dosing of the Verapamil Hcl with improved bioavailability for effective management of hypertension.

Effect of Foam-mat Drying on Bioactive, Powder and Thermal Properties of Carrot Juice Powders.

Foam-mat drying is a promising method due to involvement of proteins as foaming agent which acts like a wall material wrapping around bioactives and retards their degradation. In this study, powder properties of foam-mat dried carrot juice powders including 15% egg albumen (EA) and 15% egg albumen+ 10% whey protein isolate (WPI) during 90 days of storage at room conditions were evaluated by means of physical, chemical, thermal (DSC and TGA) and microstructural (SEM) analyses. The powder flow properties (wettability, hygroscopicity, degree of caking, Carr index and Hausner ratio) have been significantly affected from the moisture uptake during storage; however, powder flow properties of 15% EA+ 10% WPI powders were found to be better than 15% EA powders as it was also confirmed by particle diameter distributions that remained the same before and after the storage period. Besides, the total antioxidant, phenolic and carotenoid contents of 15% EA+ 10% WPI carrot powder was found comparably higher than 15% EA powders due to possible encapsulating mechanism of whey proteins. In addition to delaying of physical and chemical deteriorations in powders with WPI incorporation, thermal stability of the foam-mat dried carrot juice powders was also improved in 15% EA+ 10% WPI powder.

Adsorbent Precoating by Lyophilization: A Novel Green Solvent Technique to Enhance Cinnarizine Release from Solid Self-Nanoemulsifying Drug Delivery Systems (S-SNEDDS).

Solidification by high surface area adsorbents has been associated with major obstacles in drug release. Accordingly, new approaches are highly demanded to solve these limitations. The current study proposes to improve the drug release of solidified self-nanoemulsifying drug delivery systems (SNEDDS) to present dual enhancement of drug solubilization and formulation stabilization, using cinnarizine (CN) as a model drug. The solidification process involved the precoating of adsorbent by lyophilization of the aqueous dispersion of polymer-adsorbent mixture using water as a green solvent. Then, the precoated adsorbent was mixed with drug-loaded liquid SNEDDS to prepare solid SNEDDS. The solid-state characterization of developed cured S-SNEDDS was done using X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). In vitro dissolution studies were conducted to investigate CN SNEDDS performance at pH 1.2 and 6.8. The solidified formulations were characterized by Brunauer-Emmett-Teller (BET), powder flow properties, scanning electron microscopy, and droplet size analysis. In addition, the optimized formulations were evaluated through in vitro lipolysis and stability studies. The cured solid SNEDDS formula by PVP k30 showed acceptable self-emulsification and powder flow properties. XRD and DSC revealed that CN was successfully amorphized into drug-loaded S-SNEDDS. The uncured solid SNEDDS experienced negligible drug release (only 5% drug release after 2 h), while the cured S-SNEDDS showed up to 12-fold enhancement of total drug release (at 2 h) compared to the uncured counterpart. However, the cured S- SNEDDS showed considerable CN degradation and decrease in drug release upon storage in accelerated conditions. The implemented solidification approach offers a promising technique to minimize the adverse effect of adsorbent on drug release and accomplish improved drug release from solidified SNEDDS.

Fluidised bed agglomeration of strawberry powder mix obtained for spray drying

BACKGROUND: The microencapsulation process using spray drying (SD) represents an effective alternative in protecting the active components present in strawberries. However, microcapsules of strawberry powder mixtures present problems of instantanisation and flowability; an aspect that can be solved by agglomeration of the particles. OBJECTIVE: The aim of this study was to evaluate the influence of the fluidised bed agglomeration process on the flow, instantaneity and antioxidant properties of strawberry powder obtained by SD. METHODS: The response surface methodology (RSM) was used with a centred composite central design (α=1), considering the factors: fluidisation air temperature (50-70°C), time (30-50 min) and atomisation air pressure of the binder agent (1-2 bar). RESULTS: An increase in particle size was observed in the agglomeration process; the agglomerated particles showed a decrease in wetting time, the agglomerates of strawberry powder mixtures presented excellent instantanisation and fluidity, solving the problems identified in the microcapsules obtained by SD. CONCLUSIONS: Although the moisture and aw levels were increased in the agglomeration process, the values are within the microbiological and physicochemical food safety range; moreover, there was no effect on the phenol content and antioxidant capacity. The experimental optimisation achieved desirability of 68.4%, the optimum conditions being 70°C, 30 min and 1 bar.

Development of gluten-free cake formulations: the role of tapioca & potato starch and quinoa in the rheological, textural and powder flow properties

Development of gluten-free cake formulations: the role of tapioca & potato starch and quinoa in the rheological, textural and powder flow properties

Characterization of powder apparent viscosity: A reapplication of the Poiseuille equation to silo discharges

In the present work, a new method to characterize powder apparent viscosity was proposed by applying the Poiseuille equation to silo discharges. Flow properties of powders were first identified in terms of angle of repose and Hausner ratio, based on which experimental materials were classified as free-flowing and cohesive powders. These powders were further discharged from the pressurized silo, and an exponential increase in the powder discharge rate on the pressure difference was obtained. A model to predict the apparent viscosity was further developed grounded on the Poiseuille equation. The apparent viscosity of both free-flowing and cohesive powders decreases with an increasing flow rate within a specific range, showing the characteristic of shear-thinning. There was a reasonable agreement of powder apparent viscosity characterization between results from the silo discharge and those obtained from the FT4 rheometer, thus, confirming the method's reliability. The new method presented reliable values and had a wide testing range, providing an alternative way to measure powder rheological parameters.

Impact of pre-treatments on the surface composition, the optical and flow properties of a CuCrZr powder dedicated to laser powder bed fusion use

Laser Powder Bed Fusion is not power efficient at processing copper‑chromium‑zirconium alloy due to the high reflectivity of the powder at the laser standard wavelength (1070 nm). A way to reduce the optical reflectivity is to modify the powder surface. This work aims to study the impact of reduction and oxidation pre-treatments on the surface chemistry of the particles, and to understand their consequences on the powder properties. X-ray photoelectron spectroscopy analyses show that, starting from a 2–3 nm thick native Cu 2 O layer, a wet atmosphere leads to the formation of a 54 nm thick Cu 2 O layer, whereas a reduction under hydrogen leads to pure copper. Under argon, the Cu 2 O thickness slightly increases up to 3–4 nm. The oxidation and the reduction treatments improve the flowability, respectively, by 46% and 26%. The reduction increases the reflectivity by 2%, whereas the oxidation reduces it by 26%. • Humid atmosphere leads to a strong increase of Cu 2 O layer thickness (2–3 to 54 nm) • Reduction under H 2 leads to a pure copper surface decorated with Cr and Zr oxides • Argon atmosphere gives a slight increase of Cu 2 O layer thickness (2–3 to 3–4 nm) • Positive impact of the oxidation and the reduction treatments on powder flowability • Correlation observed between oxide layer thickness and optical reflectivity of powder

Formulation and Evaluation of Fast Disintegrating Oral Tablets of Ibuprofen using Mannitol, PEG 4000, Cellactose and Sodium Starch Glycolate via Direct Compression

Background: The needs for improve drug bioavailability has led to the development of new excipients and combination of existing excipients to yield the desired purpose. This study seeks to develop an orally fast dissolving mouth disintegrating tablet of ibuprofen using PEG 4000, mannitol, cellactose and sodium starch glycolate as a preferred alternative for patient compliance and easy administration to geriatric patients. Method: Ten batches (A1, A2, A3, B1, B2, B3, C1, C2, C3, D1, D2, & D3,) of mixture of drug and various excipients combinations were developed and evaluated for powder properties. Tablets, equivalent of 500 mg of all the batches were compacted by direct compression method, on a Cadmach rotary tableting machine using 12.5 mm round-faced punches with pressure load of 10 KN. The compressed MDTs were evaluated for friability, weight variation, hardness, content uniformity, disintegration time, in vitro drug release and tablet oral taste. Results: The results of powder flow properties and tablets analysis for all batchesA– D, batchA3, B1, B2, B3, and C1 showed promising characteristics for an ideal MDT with average powder flow rate, tablet disintegration time, T90%, crushing strength and taste as follow: A3 (1.58 gs-1, 2.09 s, 115 N, 7.5 min. and acceptable taste) respectively; B1 (1.54 gs-1, 2.01 s, 60 N, 6.5 min. and slight bitterness) respectively; B2 (1.58 gs-1, 1.52 s, 60 N, 5.5 min. and slight bitterness) respectively; B3 (1.61 gs-1, 1.05 s, 40 N, 5.0 min. and slight bitterness) respectively; C1 ( 1.72 gs-1, 0.57 s, 55 N, 4.0 min. and acceptable) respectively. Based on these characteristics, formulation batch C1 is more qualified for formulation of fast dissolving MDT. Conclusion: The fast-disintegrating oral tablets of batch C1 possessed the ideal characteristics for physical stability and rapid release ofAPI which is an indication of improved bioavailability. 

Correction: Effect of Aeration Techniques on Flow Properties of Spray-Dried Sugar Powders — Process Optimization Studies

Correction: Effect of Aeration Techniques on Flow Properties of Spray-Dried Sugar Powders — Process Optimization Studies

Moisture‐dependent engineering properties of underutilized browntop millet (unhulled and hulled) and characterization of milled flour

Browntop millet is an underutilized indigenous cereal crop. It is termed as the nutricereal due to its superiority in terms of nutritional quality. The current study attempted to investigate the effect of moisture content (10%–27%) on properties such as physical, mechanical, aerodynamic, and textural properties of unhulled and hulled browntop millet to uncover the gaps in developing the efficient primary processing machinery. In addition, we investigated the impact of milling on the biochemical, functional, color, structural, and powder flow properties of browntop millet flour. The results revealed that as the moisture content increased, the principle dimensions, 1000 grain weight, terminal velocity, angle of repose, and static coefficient of friction were linearly increased. In the same moisture content range, characteristics such as true density, bulk density, porosity, and hardness displayed an inverse trend. Milling showed a substantial (p < 0.05) influence on the nutritional, functional and color parameters. FTIR spectra and X-ray diffraction patterns demonstrated a slight change in functional groups and a slight decrease in starch crystallinity respectively. All three millet flours were cohesive. These flours, however, exhibited a positive correlation with bulk density and a negative correlation with wall friction and effective internal friction angles as the principle consolidating stress increased. Practical Application Millets are a globally significant food crop with major economic influence in developing nations. They are one of the most significant drought-resistant crops, and a good source of health-promoting complex carbohydrates, dietary fiber, phenolic compounds, and phytochemicals. Despite of their high nutritional superiority and environmental friendliness, production and consumption have declined over the years. The significant factor contributing to this decline is the lack of machinery or equipment available to process on a commercial and residential scale after harvest. The knowledge of the measured properties will encourage researchers to develop and modernize equipment used for destoning, grading, sorting, separation, dehulling, and conveying. The measured nutritional, mineral, functional, structural, and powder flow properties of milled browntop millet fractions will help develop a new product. So that millet can be used to its full potential.