Effect of residual moisture content on the survival of freeze-dried bacteria during storage under various conditions

Cryobiology ◽  
1966 ◽  
Vol 2 (5) ◽  
pp. 276-279 ◽  
Author(s):  
Tokio Nei ◽  
Hiroshi Souzu ◽  
Tadashi Araki
2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 400-407
Author(s):  
Elissa J Flaumenhaft ◽  
Terry Khat ◽  
Susanne Marschner

ABSTRACT Introduction Terumo BCT is developing a system to produce a freeze-dried plasma product, Terumo’s freeze-dried plasma (TFDP), that is stored in a rugged, light-weight plastic package suitable for field use, which retains a stable level of specific coagulation factors and proteins within clinical range, when stored for up to 2 years at room temperature and 4°C. Materials and Methods Plasma frozen within 24 hours of phlebotomy (PF24) were thawed, sampled, and individually lyophilized to produce a corresponding TFDP unit. Fresh frozen plasma (FFP) units were thawed, sampled, pooled in groups of 10 units (also sampled) and lyophilized to produce 2 lots of TFDP. Each TFDP unit was reconstituted with water for injection (WFI) and tested for pH, prothrombin time, activated partial thromboplastin time, factors V and VIII, fibrinogen, protein C, and protein S. Results were compared with PF24/FFP. Additional FFP units were thawed, sampled, pooled, divided to generate 2 TFDP units for each time point (1, 2, 3, 6, 12, 18, and 24 months, one each stored at 4°C and 25°C) and lyophilized. Postlyophilization, TFDP units were stored at 4°C or 25°C, reconstituted with WFI, and tested for the factors listed above. Residual moisture content of the lyophilized plasma was also tested. Results Coagulation factor activity of TFDP was ±20% of PF24/FFP. Pooling standardized variation in TFDP coagulation factor activities, which were within clinical ranges postlyophilization. The pH of TFDP and PF24/FFP were within required range. Residual moisture content of TFDP was <2%. Conclusions The TFDP process had no negative impact on coagulation factor activity. Input plasma and anticoagulant type did not affect TFDP quality. Pooling FFP normalized factor variability in TFDP and did not negatively impact product quality. The TFDP is stable for up to 24 months at room and refrigerated temperatures. Terumo’s freeze-dried plasma is comparable to PF24/FFP. It does not require complex logistics or time-consuming thawing. Terumo’s freeze-dried plasma may be suitable for rapid treatment of coagulopathies with logistical advantages over PF24/FFP.


1997 ◽  
Vol 62 (4) ◽  
pp. 693-695 ◽  
Author(s):  
PABLO BONELLI ◽  
CAROLINA SCHEBOR ◽  
ANA L. CUKIERMAN ◽  
MARIA P. BUERA ◽  
JORGE CHIRIFE

1985 ◽  
Vol 49 (2) ◽  
pp. 413-415 ◽  
Author(s):  
Graciela F. de Valdez ◽  
Graciela S. de Giori ◽  
Aida P. de Ruiz Holgado ◽  
Guillermo Oliver

2021 ◽  
Author(s):  
Shavkat Khurramov ◽  
Farkhad Khalturaev ◽  
Eshmurad Buriyev

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 474
Author(s):  
Daanvir K. Dhir ◽  
Armin Rashidi ◽  
Grant Bogyo ◽  
Ron Ryde ◽  
Sepideh Pakpour ◽  
...  

Natural fibers are gaining wide attention due to their much lower carbon footprint and economic factors compared to synthetic fibers. The moisture affinity of these lignocellulosic fibres, however, is still one of the main challenges when using them, e.g., for outdoor applications, leading to fast degradation rates. Plastination is a technique originally used for the preservation of human and animal body organs for many years, by replacing the water and fat present in the tissues with a polymer. This article investigates the feasibility of adapting such plastination to bamboo natural fibres using the S-10 room-temperature technique in order to hinder their moisture absorption ability. The effect of plastination on the mechanical properties and residual moisture content of the bamboo natural fibre samples was evaluated. Energy dispersive x-ray spectroscopy (EDS) and X-ray micro-computed tomography (Micro-CT) were employed to characterize the chemical composition and 3-dimensional morphology of the plastinated specimens. The results clearly show that, as plastination lessens the hydrophilic tendency of the bamboo fibres, it also decreases the residual moisture content and increases the tensile strength and stiffness of the fibers.


Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 127 ◽  
Author(s):  
Alicia Conde-Islas ◽  
Maribel Jiménez-Fernández ◽  
Denis Cantú-Lozano ◽  
Galo Urrea-García ◽  
Guadalupe Luna-Solano

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3–9 h), freezing temperature (−20 to −80 °C), pressure (0.2–0.8 mbar), and lyophilization time (5–20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p < 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of −20 °C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.


2021 ◽  
Vol 62 (4) ◽  
Author(s):  
Nguyen Thuy Huong ◽  
Le Thi Hoa ◽  
Le Quoc Hung ◽  
Ngo Thu Huong ◽  
Nguyen Dang Hien

Center for Research and Production of Vaccines and Biologicals (POLYVAC) has conducted “Study on the production process of single dose measles-rubella combined vaccine (MRVAC)” (1dose/vial) in lyophilized form to make it convenient to use for vaccination services and export. The results have determined  the formulation of MRVAC final bulk, freeze-dried process. The quality of researched products met WHO and Vietnam Pharmacopoeia V standards in both visual tests of lyophilized vaccine cake and after being reconstituted with sterile water for injection, the titer of measles virus ranges from 4.03 to 4.28 lgPFU/0.5mL and titer of rubella virus is from 3.79 to 3.98 lgPFU/0.5 mL. Results on thermal stability test when incubating the vaccine at 37oC/7days, the titer of measles virus decreased from 0.79 to 0.96 lgPFU/ 0.5mL and titer of rubella virus decreased from 0 to 0.18 lgPFU/0.5mL. Residual moisture content ranges from 0.35 to 0.72%. pH of vaccine is stable, ranges from 7.42 to 7.62.


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