China
Africa
Explore chapters and articles related to this topic
Mathematical Models for the Primary and Secondary Drying Stages of the Freeze-Drying of Pharmaceuticals on Trays and in Vials
Published in Ian Turner, Arun S. Mujumdar, Mathematical Modeling and Numerical Techniques in Drying Technology, 1996
Certain biological materials, Pharmaceuticals, and foodstuffs, which may not be heated even to moderate temperatures in ordinary drying, can be freeze dried [1- 3] . The substance to be dried is usually frozen. In freeze drying, the water or another solvent is removed as a vapor by sublimation .from the frozen material in a vacuum chamber. After the solvent sublimes to a vapor, it is removed from the drying chamber where the drying process occurs.
Freeze Drying and Microwave Freeze Drying as Encapsulation Methods
Published in Magdalini K. Krokida, Thermal and Nonthermal Encapsulation Methods, 2017
Vasiliki P. Oikonomopoulou, Magdalini K. Krokida
The shelf-life of freeze-dried products depends on storage temperature. Freeze-dried products are characterized by increased stability when the storage is performed at temperatures below their glass transition temperature (Roy and Gupta 2004).
Microwave freeze-drying of coffee solution frozen with initial pores assisted by wave-absorbing medium
Published in Drying Technology, 2023
Shuo Zhang, Yanqiu Pan, Wei Wang, Runze Lin, Shuwei Zhang
Nowadays, FD has been recognized as a well-established technology since it was known more than 100 years ago.[26] Despite its high cost in both equipment and operation, FD can find wide applications in a number of industries. The fundamental reason is that products freeze-dried are most often sensitive to heat and cannot be dried with other drying methods because of high operating temperatures. Perhaps ones’ attention to the ability of this technology to produce high-value products, such as pharmaceuticals and biomaterials, outweighed the concern about the high energy consumption of the process. Minimizing the process duration so as for increasing energy efficiency in the FD process still remains as an unsolved problem. Process enhancement entails the development of new technologies and strategies in order to save energy and maximize productivity, besides preserving product quality.[35] FD is known to consist of vial FD and tray FD.[36] In the industrial-scale tray FD, it is assumed that the plate-type geometry of materials should be accepted instead of the currently used rod-type ones. The thickness of unsaturated materials could be a bit higher than that of saturated ones, considering the superiority of unsaturated materials with prebuilt pore space. The proposed method can be beneficial and applicable to the tray FD within available freeze-driers with a certain modification toward equipment for industrial-scale food production.
A review on experimental determination and optimization of physical quality factors during pharmaceuticals freeze-drying cycles
Published in Drying Technology, 2018
Julien Andrieu, Séverine Vessot
During the freeze-drying process, the freezing step is one of the most important steps because it fixes the structure and the physical properties of the frozen material and, consequently, the final characteristics of the freeze-dried material morphology, of its rehydration properties and its stability. The degree of subcooling determines the nucleation rates, i.e., the number of nuclei formed, and, consequently, the number of ice crystals and, finally, the surface area and the mean size of the pores of the final freeze-dried matrix.
Analysis of a pharmaceutical batch freeze dryer: resource consumption, hotspots, and factors for potential improvement
Published in Drying Technology, 2019
Ana Gabriela Renteria Gamiz, Pieter-Jan Van Bockstal, Steven De Meester, Thomas De Beer, Jos Corver, Jo Dewulf
During the last decade, freeze drying of biopharmaceuticals has become the most important application of the freeze drying industry.[4] It is used as a method to preserve unstable or heat-sensitive products that cannot be dried at high temperatures such as proteins, viruses, and peptides.[5] Freeze-dried products have advantages like easy reconstitution with water, weight reduction, and stability at room temperature.[6]