scholarly journals MAGNESIUM STEARATE QUALITY INDICATORS TO ESTIMATE ITS LUBRICATION PROPERTIES

2021 ◽  
Vol 91 (1) ◽  
pp. 42-47
Author(s):  
V. N. Leontiev ◽  
O. I. Lazovskaya
Keyword(s):  
Thermal Analysis ◽  
Particle Size ◽  
Comparative Analysis ◽  
Stearic Acid ◽  
Quality Indicators ◽  
Magnesium Stearate ◽  
Medicinal Preparations ◽  
Industrial Manufacture ◽  
Heat Effects ◽  
Lubrication Properties

Industrial manufacture of palleted medicinal preparations requires the use of excipients of various purposes among which magnesium stearate is of great importance giving lubrication properties to the tabletted substance. However, magnesium stearate has an unequal lubricating effect despite the fact that quality indicators of magnesium stearate from different manufacturers comply with the requirements of the Pharmacopoeia Monograph. In this work, a comparative analysis of magnesium stearate quality indicators from Merck KGaA (Germany) and Accent Microcell Pvt. Ltd. (India) was carried out. It was found that magnesium stearate from Merck KGaA (Germany) has the best lubrication properties having the smallest particle size and predominantly dihydrated form and characterized by the highest content of stearic acid. To identify hydrated forms of magnesium stearate thermal analysis was used making it possible to determine dehydration temperatures and melting of pseudopolymorphic structures by endothermic heat effects.

Physical and Lubrication Properties of Magnesium Stearate

1992 ◽  
Vol 81 (12) ◽  
pp. 1194-1198 ◽  
Author(s):  
U.I. Leinonen ◽  
H.U. Jalonen ◽  
P.A. Vihervaara ◽  
E.S.U. Laine
Keyword(s):  
Magnesium Stearate ◽  
Lubrication Properties

Finite-element modelling of thermo-mechanical stress distribution in laser beam ceramic tile grout sealing process

2006 ◽  
Vol 220 (10) ◽  
pp. 1497-1508 ◽  
Author(s):  
A Liaqat ◽  
S Safdar ◽  
M A Sheikh
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Laser Beam ◽  
Mechanical Stress ◽  
Ceramic Tile ◽  
Element Model ◽  
Ceramic Tiles ◽  
Temperature Dependent ◽  
Heat Effects

Laser tile grout sealing is a special process in which voids between the adjoining ceramic tiles are sealed by a laser beam. This process has been developed by Lawrence and Li using a customized grout material and a high power diode laser (HPDL). The process has been optimally carried out at laser powers of 60–120 W and at scanning speeds of 3–15 mm/s. Modelling of the laser tile grout sealing process is a complex task as it involves a moving laser beam and five different materials: glazed enamel, grout material, ceramic tile, epoxy bedding, and ordinary Portland cement substrate. This article presents the finite element model (FEM) of the laser tile grout sealing process. The main aim of this model is to accurately predict the thermo-mechanical stress distribution induced by the HPDL beam in the process. For an accurate representation of the process, the laser was modelled as a moving heat source. A three-dimensional transient thermal analysis was carried out to determine the temperature distribution. Temperature-dependent material properties and latent heat effects, due to melting and solidification of the glazed enamel, were taken into account in the FEM, thereby allowing a more realistic and accurate thermal analysis. The results of the thermal analysis were used as an input for the stress analysis with temperature-dependent mechanical properties. The results obtained from the FEM are compared with the published experimental results.

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