Angle of Repose by Wallace Stegner

1971 ◽  
Vol 6 (1) ◽  
pp. 60-62
Author(s):  
J. S. Bullen
Keyword(s):  
Angle Of Repose ◽  
Wallace Stegner

FORMULATION AND DEVELOPMENT OF FAST DISSOLVING TABLET OF METOCLOPRAMIDE: AN ANTI-EMETIC DRUG

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya
Keyword(s):  
Mechanical Strength ◽  
Standard Procedure ◽  
Flow Property ◽  
Storage Conditions ◽  
Angle Of Repose ◽  
Dissolution Time ◽  
Disintegration Time ◽  
Powder Blend ◽  
Standard Curve ◽  
The Stability

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet

Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models

2000 ◽  
Vol 627 ◽  
Author(s):  
M. E. Swanson ◽  
M. Landreman ◽  
J. Michel ◽  
J. Kakalios
Keyword(s):  
Continuous Flow ◽  
Granular Media ◽  
Experimental Tests ◽  
Coarse Sand ◽  
Angle Of Repose ◽  
Flow Models ◽  
Maximum Angle ◽  
Stratification Effect ◽  
Upward Moving ◽  
Moving Layer

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

The Effect of Superdisintegrants on the Dissolution of Promethazine. HCl Fast Dissolving Tablets

2010 ◽  
Vol 3 (1) ◽  
pp. 867-871
Author(s):  
Ganesh kumar Gudas ◽  
Manasa B ◽  
Senthil Kumaran K ◽  
Rajesham V V ◽  
Kiran Kumar S ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Angle Of Repose ◽  
Content Uniformity ◽  
Disintegration Time ◽  
Enhanced Dissolution ◽  
Weight Variation ◽  
Compressibility Index ◽  
Chemoreceptor Trigger Zone ◽  
Trigger Zone ◽  
Standard Limit

Promethazine.HCl is a potent anti-emetic. The central antimuscarinic actions of antihistamines are probably responsible for their anti-emetic effects. Promethazine is also believed to inhibit the medullary chemoreceptor trigger zone, and antagonize apomorphine -induced vomiting. Fast dissolving tablets of Promethazine.HCl were prepared using five superdisintegrants viz; sodium starch glycolate, crospovidone, croscarmellose, L-HPC and pregelatinised starch. The precompression blend was tested for angle of repose, bulk density, tapped density, compressibility index and Hausner’s ratio. The tablets were evaluated for weight variation, hardness, friability, disintegration time (1 min), dissolution rate, content uniformity, and were found to be within standard limit. It was concluded that the fast dissolving tablets with proper hardness, rapidly disintegrating with enhanced dissolution can be made using selected superdisintegrants. Among the different formulations of Promethazine.HCl was prepared and studied and the formulation S2 containing crospovidone, mannitol and microcrystalline cellulose combination was found to be the fast dissolving formulation. In the present study an attempt has been made to prepare fast dissolving tablets of Promethazine.HCl, by using different superdisintegrants with enhanced disintegration and dissolution rate. 

Formulation and Evaluation of Sustained Release Dosage Forms of Norfloxacin

2018 ◽  
Vol 11 (6) ◽  
pp. 4331-4337
Author(s):  
C Suja ◽  
Sismy C
Keyword(s):  
Sustained Release ◽  
Guar Gum ◽  
In Vitro Release ◽  
Angle Of Repose ◽  
Prolonged Release ◽  
Weight Variation ◽  
Sustained Release Tablets ◽  
Release Study ◽  
Vitro Release

The goal of this study was to formulate and evaluate norfloxacin sustained release tablets. Norfloxacin sustained release tablets were prepared by wet granulation method using two polymers such as HPMC K 100 M (hydrophilic polymer) and guar gum (natural polymer) and with three polymer ratios (0.5, 1.0 and 1.5). The prepared granules were evaluated to preformulation studies such as angle of repose, bulk density, tapped density, bulkiness, compressibility index and Hauser’s ratio. All the parameters shows that the granules having good flow properties. Then the formulated tablets were taken to evaluation studies such as hardness, weight variation, friability, drug content and thickness. All the parameters were within the acceptable limits. IR spectral analysis showed that there was no interaction between the drug and polymers. The in vitro release study was performed in phosphate buffer pH 7.4 at 293 nm. The in vitro release study showed that if the polymer ratio is increased, then the release of the drug is prolonged. HPMC K 100M shows a prolonged release when compared to guar gum.

Influence of temperature and humidity on the angle of repose of wood bulk materials

2016 ◽  
Author(s):  
И.В. Бачериков ◽  
Б.М. Локштанов
Keyword(s):  
Field Experiments ◽  
Bulk Material ◽  
Average Particle Size ◽  
Operating Conditions ◽  
Angle Of Repose ◽  
Wood Dust ◽  
Average Particle ◽  
Bulk Materials ◽  
Technical Literature ◽  
The Impact

При проектировании открытых и закрытых хранилищ измельченных сыпучих материалов древесных материалов, таких как щепа и опилки, большое значение имеет угол естественного откоса (статический и динамический) этих материалов. В технической литературе приводятся противоречивые сведения о величине этих углов, что приводит к ошибкам при проектировании складов. В справочных данных не учитываются условия, в которых эксплуатируются емкости для хранения сыпучих материалов, свойства и состояние этих сыпучих материалов. В свою очередь, ошибки при проектировании приводят к проблемам (зависание, сводообразование, «затопление» и т. д.) и авариям при эксплуатации бункеров и силосов на производстве. В статье представлены сведения, посвященные влиянию влажности и температуры на угол естественного откоса сыпучих материалов. На основании лабораторных и натурных экспериментов, проведенных с помощью специально разработанных методик и установок, была скорректирована формула для определения углов естественного откоса (статического и динамического) для измельченных древесных материалов в зависимости от их фракционного и породного состава, влажности (абсолютной и относительной) и температуры. При помощи скорректированной формулы можно определить угол естественного откоса древесных сыпучих материалов со среднегеометрическим размером частицы от 0,5 мм до 15 мм (от древесной пыли до технологической щепы) в различных производственных условиях. Статья может быть полезна проектировщикам при расчете угла наклона граней выпускающей воронки бункеров и силосов предприятий лесной отрасли и целлюлозо-бумажной промышленности. In the design of open and closed storage warehouses chopped wood materials for bulk materials such as wood chips and sawdust, great importance has an angle of repose (static and dynamic) of these materials. In the technical literature are conflicting reports about the magnitude of these angles, which leads to errors in the design of warehouses. In the referencesdoes not take into account the conditions under which operated capacities for storage of bulk materials, and properties and condition of the bulk material. The design errors lead to problems (hanging, arching, «flooding», etc.) and accidents in the operation of hoppers and silos at the mills. The article provides information on the impact of humidity and temperature on the angle of repose of granular materials. On the basis of laboratory and field experiments, conducted with the help of specially developed techniques and facilities has been adjusted formula for determining the angle of repose (static and dynamic) for the shredded wood materials depending on their fractional and species composition, humidity (absolute and relative) and temperature. It is possible, by using the corrected formula, to determine the angle of repose of loose wood materials with average particle size of from 0.5 mm to 15 mm (wood dust to pulpchips) in various operating conditions. The article can be helpful to designers in the calculation of the angle of inclination of the funnel faces produces bunkers and silos forest industries and pulp and paper industry.

Application of 32 Full Factorial Design and Desirability Function for Optimizing The Manufacturing Process for Directly Compressible Multi-Functional Co-Processed Excipient

2020 ◽  
Vol 17 (6) ◽  
pp. 523-539
Author(s):  
Jalpa Patel ◽  
Dhaval Mori
Keyword(s):  
Factorial Design ◽  
Spray Drying ◽  
Desirability Function ◽  
Full Factorial Design ◽  
Angle Of Repose ◽  
P Value ◽  
Independent Variables ◽  
Full Factorial ◽  
32 Full Factorial Design ◽  
Response Variables

Background: Developing a new excipient and obtaining its market approval is an expensive, time-consuming and complex process. Compared to that, the co-processing of already approved excipients has emerged as a more attractive option for bringing better characteristic excipients to the market. The application of the Design of Experiments (DoE) approach for developing co-processed excipient can make the entire process cost-effective and rapid. Objective: The aim of the present investigation was to demonstrate the applicability of the DoE approach, especially 32 full factorial design, to develop a multi-functional co-processed excipient for the direct compression of model drug - cefixime trihydrate using spray drying technique. Methods: The preliminary studies proved the significant effect of atomization pressure (X1) and polymer ratio (microcrystalline cellulose: mannitol - X2) on critical product characteristics, so they were selected as independent variables. The angle of repose, Carr’s index, Hausner’s ratio, tensile strength and Kuno’s constant were selected as response variables. Result: The statistical analysis proved a significant effect of both independent variables on all response variables with a significant p-value < 0.05. The desirability function available in Design Expert 11® software was used to prepare and select the optimized batch. The prepared co-processed excipient had better compressibility than individual excipients and their physical mixture and was able to accommodate more than 40 percent drug without compromising the flow property and compressibility. Conclusion: The present investigation successfully proved the applicability of 32 full factorial design as an effective tool for optimizing the spray drying process to prepare a multi-functional co-processed excipient.

Enhanced oral bioavailability of Etodolac by liquisolid compact technique: optimisation, in-vitro and in-vivo evaluation

2020 ◽  
Vol 17 ◽  
Author(s):  
Bhumin K. Pathak ◽  
Meenakshi Raghav ◽  
Arti R. Thakkar ◽  
Bhavin A. Vyas ◽  
Pranav J. Shah
Keyword(s):  
Dissolution Rate ◽  
Amorphous State ◽  
Immediate Release ◽  
Angle Of Repose ◽  
Oral Suspension ◽  
Load Factor ◽  
In Vivo Evaluation ◽  
Rate Of Dissolution ◽  
Q 30

Background: Poor dissolution of Etodolac is one of the major challenges in achieving the desired therapeutic effect in oral therapy. Objective: This study aimed to assess the potential of liquisolid compact technique in increasing the rate of dissolution of Etodolac and thus its bioavailability. Methods: Liquisolid compacts were prepared using PEG 400, Avicel PH-200 and Aerosil 200 as non-volatile liquid, carrier and coating material respectively. Optimisation was carried out by applying a 32 full factorial design using Design expert software 11.0.3.0 to examine the effects of independent variables (load factor and carrier: coating ratio) on dependent variables (angle of repose and % cumulative drug release at 30 min [Q 30 min]).Assessment of bioavailability was based on pharmacokinetic study in rabbits and pharmacodynamics evaluation in rats respectively. Results: The formulation M3 was identified as the optimised formulation based on the better flow (lower angle of repose) and a higher rate of dissolution (Q 30 min >95%). The higher dissolution rate could be due to conversion of Etodolac into an amorphous molecularly dispersed state, availability of larger surface area, enhancement of aqueous solubility and enhanced wetting of drug particles. Studies with DSC, XRD, and SEM verified the transformation of Etodolac from crystalline to amorphous state, a key factor responsible for improving the dissolution rate. Pharmacokinetic profile of M3 was prominent, demonstrating higher absorption of Etodolac in comparison of oral suspension and immediate-release conventional tablets in rabbits. Liquisolid formulation exhibited 27% increment in paw thickness as compared to 57% and 46% increments for oral suspension and immediate-release conventional tablets respectively, after 7 hrs in carrageenan-induced paw model in rats. Conclusion: The results indicated liquisolid compact technique to be a promising strategy to enhance the bioavailability of Etodolac.

Exploration of Neem Gum, Acrylamide Grafted Neem Gum and Carboxymethylated Neem Gum as Retardant in Tablet Formulation

2020 ◽  
Vol 16 (9) ◽  
pp. 1404-1410
Author(s):  
Rishabha Malviya
Keyword(s):  
Diclofenac Sodium ◽  
Tablet Formulation ◽  
Angle Of Repose ◽  
Wet Granulation ◽  
Binding Agent ◽  
Grafted Polymer ◽  
Model Drug ◽  
Tablet Dosage ◽  
Tapped Density ◽  
Derivatives Of

Background: In the previous study, investigators have synthesized acrylamide grafted and carboxymethylated derivatives of neem gum and evaluated their potential in the formulation of nanoparticles. In continuation of previous work, authors have evaluated neem gum polysaccharide (NGP), acrylamide grafted neem gum polysaccharide (NGP-g-Am) and carboxymethylated neem gum polysaccharide (CMNGP) as binding agent in the tablet dosage form. Methods: Diclofenac sodium was used as a model drug while microcrystalline cellulose and talc were used as excipient in the preparation of granules employing wet granulation technique. NGP, NGP-g-Am and CMNGP were utilized as binding agent in the preparation of granules. Prepared granules were characterized for various pre-compression and post-compression parameters. Results and Discussion: Binding agents were used in the concentration of 4-24%w/w. NGP incorporated granules showed more bulk density and lower values of tapped density, Carr’s index, bulkiness, Hausner’s ratio and angle of repose as compared to NGP-g-Am consisting granules. NGP-g-Am consisting tablets showed more hardness and zero friability as compared to NGP based tablets. Drug content was found lower for the tablets having grafted polymer in place of NGP. CMNGP were also utilized to prepare granules but granules were not be able to compress keeping all the compacting parameters same as used in the case of NGP and NGP-g-Am consisting granules. NGP and NGP-g-Am were able to sustain drug release up to 6 and 8 h, respectively. Conclusion: It can be concluded that NGP-g-Am induces better properties when used as a binder in the tablet formulation than native polymer, while CMNGP cannot be utilized as a binding agent in the preparation of a tablet.

scholarly journals Algorithm for the determination of the angle of repose in bulk material analysis

2021 ◽  
Vol 383 ◽  
pp. 598-605
Author(s):  
Dominik Müller ◽  
Eric Fimbinger ◽  
Clemens Brand
Keyword(s):  
Bulk Material ◽  
Angle Of Repose ◽  
Material Analysis
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