Effect of Secondary Drying Impregnation on the Breakdown Characteristics of Oil-Paper

Author(s):  
Pengfei Xu ◽  
Lijun Yang ◽  
Huanchao Cheng
Keyword(s):  
2020 ◽  
pp. 1-15 ◽  
Author(s):  
Getachew Assegehegn ◽  
Edmundo Brito-de la Fuente ◽  
José M. Franco ◽  
Críspulo Gallegos

2011 ◽  
Vol 100 (2) ◽  
pp. 732-742 ◽  
Author(s):  
Davide Fissore ◽  
Roberto Pisano ◽  
Antonello A. Barresi

2008 ◽  
Vol 41 (3) ◽  
pp. 696-698
Author(s):  
M. E. LAZAR ◽  
T. RUMSEY
Keyword(s):  

Author(s):  
ILYA GULYAKIN ◽  
ANNA LANTSOVA ◽  
LYUDMILA NIKOLAEVA ◽  
MARIA DMITRIEVA ◽  
NATALIYA OBOROTOVA ◽  
...  

Objective: Development of a lyophilized injectable dosage form LCS-1208, an original antitumor drug based on an indolocarbazole derivative. Methods: The prepared solution of the injectable dosage form LCS-1208 is transferred to sterilizing filtration, which is carried out under vacuum on a «Stericup» filter unit with a filter pore size of 0.22 μm. The sterile solution of the injectable dosage form LCS-1208 is poured into sterile vials using a dispenser and lyophilized in a freeze-drying chamber. At the end of drying, the preparation is corked in the chamber of a sublimation unit using a hydraulic device and transferred to crimping with aluminum caps using a seaming machine. Quantitative determination of the drug content was determined by spectrophotometry using a standard sample at λ = 320±2 nm. The pH was determined by potentiometry. Results: A freeze-drying regimen for the injectable dosage form LCS-1208 has been developed. The required solution freezing temperature was established taking into account the presence of 2 eutectic zones: a solution of LCS-1208 in DMSO (-35 ÷-32) °С, an aqueous solution of Kollidon 17PF (-10 ÷-8) °С. As a result of a series of experiments, the optimal lyophilization regime was chosen that does not require preliminary freezing in a low-temperature chamber, with freezing on the shelves of freeze-drying at a temperature of-47 °C without their preliminary cooling. The most acceptable vial filling volume was determined, amounting to 3 ml, and the rate of temperature rise during secondary drying of the preparation was justified. When using the developed regime of lyophilization of the LCS-1208 solution, it was shown that it can be sublimated while preserving the initial qualitative and quantitative characteristics. Conclusion: In this article, using the example of creating a lyophilized injectable dosage form LCS-1208 (the original antitumor drug from the indolocarbazole group), the main problems that arose during the lyophilization of the selected composition of the model solution, as well as ways to improve the process.


2004 ◽  
Vol 58 (12) ◽  
pp. 552-562 ◽  
Author(s):  
Dejan Przic ◽  
Nenad Ruzic ◽  
Slobodan Petrovic

This article presents a general overview of lyophilization and discusses the underlying principles of the process through the basics of: formulation, freezing, primary drying and secondary drying. In this article lyophilization is defined as a stabilizing process in which the substance is first frozen and then the quantity of the solvent is reduced first by sublimation (primary drying) and then by desorption (secondary drying) to values that will no longer support biological growth or chemical reactions. Special mention was made of the industrial use of the process and emphasis was placed on the lyophilization of pharmaceutical products and food industry products. Lyophilization equipment, as well as the formulation of materials that can be lyophilized, are described in sufficient detail to give information on the restrictions and advantages of lyophlization. Processing economics and comparison with conventional drying methods are presented. A historical overview of the process and future developments presented from the industrial viewpoint give an insight on the previous application of lyophilization and the prospects of its broad industrial use.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 329 ◽  
Author(s):  
Panna Vass ◽  
Edit Hirsch ◽  
Rita Kóczián ◽  
Balázs Démuth ◽  
Attila Farkas ◽  
...  

The aims of this work were to develop a processable, electrospun formulation of a model biopharmaceutical drug, β-galactosidase, and to demonstrate that higher production rates of biopharmaceutical-containing fibers can be achieved by using high-speed electrospinning compared to traditional electrospinning techniques. An aqueous solution of 7.6 w/w% polyvinyl alcohol, 0.6 w/w% polyethylene oxide, 9.9 w/w% mannitol, and 5.4 w/w% β-galactosidase was successfully electrospun with a 30 mL/h feeding rate, which is about 30 times higher than the feeding rate usually attained with single-needle electrospinning. According to X-ray diffraction measurements, polyvinyl alcohol, polyethylene oxide, and β-galactosidase were in an amorphous state in the fibers, whereas mannitol was crystalline (δ-polymorph). The presence of crystalline mannitol and the low water content enabled appropriate grinding of the fibrous sample without secondary drying. The ground powder was mixed with excipients commonly used during the preparation of pharmaceutical tablets and was successfully compressed into tablets. β-galactosidase remained stable during each of the processing steps (electrospinning, grinding, and tableting) and after one year of storage at room temperature in the tablets. The obtained results demonstrate that high-speed electrospinning is a viable alternative to traditional biopharmaceutical drying methods, especially for heat sensitive molecules, and tablet formulation is achievable from the electrospun material prepared this way.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1488 ◽  
Author(s):  
Dorota Nowak ◽  
Ewa Jakubczyk

Freeze-drying, also known as lyophilization, is a process in which water in the form of ice under low pressure is removed from a material by sublimation. This process has found many applications for the production of high quality food and pharmaceuticals. The main steps of the freeze-drying process, such as the freezing of the product and primary and secondary drying, are described in this paper. The problems and mechanisms of each step of the freeze-drying process are also analyzed. The methods necessary for the selection of the primary and secondary end processes are characterized. The review contains a description of the effects of process conditions and the selected physical properties of freeze-dried materials, such as structural properties (shrinkage and density porosity), color, and texture. The study shows that little attention is given to the mechanical properties and texture of freeze-dried materials obtained from different conditions of the lyophilization process.


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