Protein structure and freeze-drying: The effects of residual moisture and gases

Cryobiology ◽  
1971 ◽  
Vol 8 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Donald Greiff
2019 ◽  
Vol 35 (4) ◽  
pp. 73-78
Author(s):  
S.E. Gostischeva ◽  
D.V. Rostovtseva ◽  
G.F. Ivanova ◽  
A.V. Kostrominov ◽  
M.V. Pilipenko

The optimization of the drying schedule has been carried out to improve the quality indicators of the live plague vaccine. Based on the data obtained on the eutectic point of the vaccine suspension, the freezing temperature and freezing time were set to -50 °С and 6-7 h, respectively. A pressure of 40 mTorr over the surface of the drying suspension and 20 mTorr during the desorption were shown to be the best conditions for sublimation. The drying tests with different options for the shelf heating rate, vacuum depth and duration of intermediate temperature indicators were carried out to develop the improved freeze-drying mode providing the selection of the most adapted bacteria. A vaccine lyophilized under the developed conditions has low residual moisture (up to 2%) and high viability index that persists over the whole shelf life. lyophilization, sublimation, eutectic, live plague vaccine, residual moisture, viability


Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 616 ◽  
Author(s):  
Christina Haeuser ◽  
Pierre Goldbach ◽  
Joerg Huwyler ◽  
Wolfgang Friess ◽  
Andrea Allmendinger

Short freeze-drying cycles for biopharmaceuticals are desirable. Formulations containing an amorphous disaccharide, such as sucrose, are prone to collapse upon aggressive primary drying at higher shelf temperature. We used 2-hydroxypropyl-betacyclodextrin (HPBCD) in combination with sucrose and polyvinylpyrrolidone (PVP) to develop an aggressive lyophilization cycle for low concentration monoclonal antibody (mAb) formulations. Glass transition temperature and collapse temperature of the formulations were determined, and increasingly aggressive cycle parameters were applied. Using a shelf temperature of +30 °C during primary drying, the concept of combining sublimation and desorption of water in a single drying step was investigated. Cake appearance was evaluated visually and by micro-computed tomography. Lyophilisates were further analyzed for reconstitution time, specific surface area, residual moisture, and glass transition temperature. We demonstrated the applicability of single-step freeze-drying, shortening the total cycle time by 50% and providing elegant lyophilisates for pure HPBCD and HPBCD/sucrose formulations. HPBCD/PVP/sucrose showed minor dents, while good mAb stability at 10 mg/mL was obtained for HPBCD/sucrose and HPBCD/PVP/sucrose when stored at 40 °C for 3 months. We conclude that HPBCD-based formulations in combination with sucrose are highly attractive, enabling aggressive, single-step freeze-drying of low concentration mAb formulations, while maintaining elegant lyophilisates and ensuring protein stability at the same time.


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.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Marcin Czyż ◽  
Radosław Dembczyński ◽  
Roman Marecik ◽  
Justyna Wojas-Turek ◽  
Magdalena Milczarek ◽  
...  

The aim of this study was to develop a freeze-drying protocol facilitating successful processing of plant material containing the small surface antigen of hepatitis B virus (S-HBsAg) while preserving its VLP structure and immunogenicity. Freeze-drying of the antigen in lettuce leaf tissue, without any isolation or purification step, was investigated. Each process step was consecutively evaluated and the best parameters were applied. Several drying profiles and excipients were tested. The profile of 20°C for 20 h for primary and 22°C for 2 h for secondary drying as well as sucrose expressed efficient stabilisation of S-HBsAg during freeze-drying. Freezing rate and postprocess residual moisture were also analysed as important factors affecting S-HBsAg preservation. The process was reproducible and provided a product with VLP content up to 200 µg/g DW. Assays for VLPs and total antigen together with animal immunisation trials confirmed preservation of antigenicity and immunogenicity of S-HBsAg in freeze-dried powder. Long-term stability tests revealed that the stored freeze-dried product was stable at 4°C for one year, but degraded at elevated temperatures. As a result, a basis for an efficient freeze-drying process has been established and a suitable semiproduct for oral plant-derived vaccine against HBV was obtained.


Cryobiology ◽  
1971 ◽  
Vol 8 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Edward B. Seligmann ◽  
Jane F. Farber

2018 ◽  
Vol 14 (11-12) ◽  
Author(s):  
Ertan Ermis ◽  
Kübra Özkan Güner ◽  
Mustafa Tahsin Yilmaz

Abstract Production of hazelnut milk powder (HMP) was investigated using maltodextrin (MD) as supporting material. Spray-drying and freeze-drying techniques were used to obtain the powder material. MD was added at concentrations of 5%, 10% and 15% (w/w) prior to drying. The powder properties were evaluated by determining flowing properties (Hausner ratio and angle of repose), thermal behaviour using DSC, molecular properties using FTIR, solubility and zeta potential. Hausner Ratio for both spray dried (SDHMP) and freze-dried (FDHMP) samples varied from 1.30 to 1.64 corresponding to very poor flow. The FDHM powder samples exhibited slightly lower Hausner Ratio values than SDHM powders. FTIR spectras showed that both SDHM and FDHM exhibited similar absorbance characteristics with slight differences. Lower endothermic transition temperatures were recorded from FDHMP when compared to SDHMP. The solubility in water for both powder samples ranged from 20 to 65 % depending on the drying method and MD content. Based on the residual moisture content, water activity, solubility and flowability, spray drying process was found to produce better quality powders compared to freeze drying process.


2010 ◽  
Vol 3 ◽  
pp. MBI.S2728 ◽  
Author(s):  
Stephenie Wong ◽  
Barka Mohammed Kabeir ◽  
Shuhaimi Mustafa ◽  
Rosfarizan Mohamad ◽  
Anis Shobirin Meor Hussin ◽  
...  

Viability of Bifidobacterium pseudocatenulatum G4 following spray-drying and freeze-drying in skim milk was evaluated. After spray-drying, the strain experienced over 99% loss in viability regardless of the air outlet temperature (75 and 85 °C) and the heat-adaptation temperature (45 and 65 °C, 30 min). The use of heat-adaptation treatment to improve the thermotolerance of this strain was ineffective. On the other hand, the strain showed a superior survival at 71.65%–82.07% after freeze-drying. Viable populations of 9.319–9.487 log10 cfu/g were obtained when different combinations of skim milk and sugar were used as cryoprotectant. However, the addition of sugars did not result in increased survival during the freeze-drying process. Hence, 10% (w/v) skim milk alone is recommended as a suitable protectant and drying medium for this strain. The residual moisture content obtained was 4.41% ± 0.44%.


2021 ◽  
pp. 1-11
Author(s):  
Zhe Wang ◽  
Xu Duan ◽  
Linlin Li ◽  
Guangyue Ren ◽  
Tiantian Wu ◽  
...  

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