Study of effect of various disintegrants on the physical properties and dissolution behavior of the directly compressed theophylline tablets

2002 ◽  
Vol 25 (1) ◽  
pp. 23-30
Author(s):  
N. Aldouri ◽  
M. Ahmed ◽  
S. El-Jamal
Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5273
Author(s):  
Jungsoo Han ◽  
Yungbum Seo

Three alkaline mixtures (NaOH/thiourea, NaOH/urea/thiourea, NaOH/urea/ZnO) and sulfuric acid were used at low temperatures as cellulose solvents, and their cellulose solubility and films’ physical properties for bleached chemical wood pulps and cotton linter were compared. Their degree of polymerization (DP) was controlled to 600–800 before dissolution. Among the alkaline solvents, NaOH/urea/ZnO gave the film the highest tensile strength and stretch. When compared to sulfuric acid, NaOH/urea/ZnO gave lower strength properties but higher crystallinity indices in the films. While alkaline solvents could not dissolve the high DP cellulose (DP ~ 2000), sulfuric acid could dissolve the high DP cellulose at below zero Celsius temperature, and the strength properties of the films were not much different from that of the low DP one. It appeared that the low-temperature sulfuric acid treatment did away with the cellulose’s DP controlling stage; it decreased cellulose DP very quickly for the high-DP cellulose at the initial stage, and as soon as the cellulose DP reached a DP low enough for dissolution, it began to dissolve the cellulose to result in stable cellulose solution.


1998 ◽  
Vol 31 (4) ◽  
pp. 1024-1031 ◽  
Author(s):  
G. G. Barclay ◽  
C. J. Hawker ◽  
H. Ito ◽  
A. Orellana ◽  
P. R. L. Malenfant ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 814
Author(s):  
Wei-Feng Zhu ◽  
Lin Zhu ◽  
Zhe Li ◽  
Wen-Ting Wu ◽  
Yong-Mei Guan ◽  
...  

It is necessary to prepare porous lactose in order to improve the dissolution behavior of insoluble active ingredient. In this study, polyvinylpyrrolidone K30 (PVP K30) was firstly utilized as a templating agent with different use levels in preparing porous lactose. Then, the physical properties were profoundly characterized. Finally, the porous lactose was also employed as a health functional food/drug carrier to explore the effect on the dissolution behavior of curcumin. The results confirmed that (i) porous lactose was successfully prepared using PVP K30 as templating agent; (ii) PVP K30 significantly improved the yield of lactose in the spray drying; (iii) the improved powder properties of porous lactose were more conducive to the downstream operating process for the preparation of health functional food or drug; and (iv) the porous lactose significantly improved the dissolution behavior of curcumin. Therefore, the results obtained are beneficial to boosting the development of porous materials.


1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).


Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.


Author(s):  
K.P.D. Lagerlof

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.


Author(s):  
James Mark ◽  
Kia Ngai ◽  
William Graessley ◽  
Leo Mandelkern ◽  
Edward Samulski ◽  
...  
Keyword(s):  

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik

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