Dissolution Rate Studies of Cholesterol Monohydrate in Bile Acid–Lecithin Solutions Using the Rotating‐Disk Method

1976 ◽  
Vol 65 (5) ◽  
pp. 685-689 ◽  
Author(s):  
S. Prakongpan ◽  
W.I. Higuchi ◽  
K.H. Kwan ◽  
A.M. Molokhia
2014 ◽  
Vol 50 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Leandro Giorgetti ◽  
Michele Georges Issa ◽  
Humberto Gomes Ferraz

The aim of this study was to evaluate the effect of dissolution medium, rotation speed and compaction pressure on the intrinsic dissolution rate (IDR) of the antihypertensive drug amlodipine besylate, using the rotating disk method. Accordingly, a fractional factorial design (33-1) was used, employing dissolution media (water, phosphate buffer pH 6.8 and HCl 0.1 M), rotation speed (50, 75 and 100 rpm), and compaction pressure (1000, 1500 and 2000 psi) as independent variables. The assays were randomized and statistically compared using the Statistica(r) 11 software program. Significance testing (ANOVA) indicated that the dissolution medium had a considerable impact on the IDR of amlodipine besylate. Analysis of the linear and quadratic components of the variables led to the proposition of a mathematical model that describes the IDR as a function of the parameters studied. Conversely, the levels of compaction pressure and rotation speed employed during experimental planning were less relevant, especially when the assay was conducted in the HCl 0.1 M medium.


1966 ◽  
Vol 14 (4) ◽  
pp. 329-338 ◽  
Author(s):  
Hisashi Nogami ◽  
Tsuneji Nagai ◽  
Akira Suzuki

2013 ◽  
Vol 13 (8) ◽  
pp. 3596-3602 ◽  
Author(s):  
Richard S. Abendan ◽  
Jennifer A. Swift

2018 ◽  
Vol 284 ◽  
pp. 877-881
Author(s):  
Sergey E. Polygalov ◽  
S.A. Mastugin ◽  
E.A. Shadrina

The work is devoted to the study of the possibilities of minimizing the release of nitrogen oxides during the dissolution of silver in nitric acid solutions during refining of the gold and silver alloy. Using a rotating disk, the maximum concentration of nitric acid is determined, at which the oxidation potential of the system is insufficient for the oxidation of silver. It has been established that at a temperature of 363 K and a concentration of HNO3 = 50 g/l, the dissolution rate of silver does not exceed 0.00022∙10-5 mol/(cm2∙s), and such conditions can be considered as background for an environmentally friendly process. To initiate dissolution, hydrogen peroxide was used as an alternative oxidizing agent. As a criterion for the rational use of the oxidant and the ecological purity of the process, the excess pressure over the solution was evaluated. The influence of the initial and current composition of the solution, temperature, and conditions of oxidant supply to the reactor on the kinetics of the target process was studied. It is shown that at a silver dissolution rate of 2.7∙10-6 mol/(cm2∙s), no release of nitrogen oxides was observed.


2012 ◽  
Vol 238 ◽  
pp. 153-156 ◽  
Author(s):  
Daniel Dobiáš

The paper introduces the rotating disk method, its features and the scope of application. It also describes the application of this technique in the research of corrosion of cement-based materials caused by aggressive liquid solutions and the effect of flow of solutions on the corrosion rate


2018 ◽  
pp. 29-32
Author(s):  
D. S. Reutov ◽  
◽  
B. D. Khalezov ◽  
L. A. Ovchinnikova ◽  
A. S. Gavrilov ◽  
...  

1976 ◽  
Vol 55 (3) ◽  
pp. 496-505 ◽  
Author(s):  
Maw-Sheng Wu ◽  
William I. Higuchi ◽  
Jeffrey L. Fox ◽  
Michael Friedman

The dissolution rates of synthetic hydroxyapatite pellets under sink conditions were measured using the rotating disk method. The experimental data were analyzed by means of a physical model that yielded an ionic activity product of KHAP = a10 Ca2+ a6 PO4 3- a2OH- = 1 × 10-124.5±1.0 that was found to govern the dissolution reaction. Also, a surface resistance factor of k' equal to about 174 sec/cm was deduced from the data.


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