scholarly journals Long term stability and interaction with epithelial cells of freeze-dried pH-responsive liposomes functionalized with cholesterol-poly(acrylic acid)

2018 ◽  
Vol 164 ◽  
pp. 50-57 ◽  
Author(s):  
M.G. Simões ◽  
A. Hugo ◽  
P. Alves ◽  
P.F. Pérez ◽  
A. Gómez-Zavaglia ◽  
...  
2020 ◽  
Vol 20 (6) ◽  
pp. 3598-3603 ◽  
Author(s):  
Yingying Ma ◽  
Jin Gao ◽  
Wankui Jia ◽  
Yangyang Liu ◽  
Lanying Zhang ◽  
...  

Spray-drying and freeze-drying are effective approaches to improve the long-term stability of nanosuspensions. This research explored the effect of spray-drying and freeze-drying techniques on PVP K30-stabilized silybin nanosuspensions. The morphology was observed by scanning electron microscopy (SEM): The spray-dried sample was spherical, and the freeze-dried samples were rodlike with smooth surfaces. The redispersibility was studied via dynamic light scattering (DLS): The size, PDI, and zeta of the spray-dried sample were 133.27 nm, 0.214, and 24.37 mV, respectively; the size, PDI, and zeta of the freeze-dried sample were 298.70 nm, 0.114, and 20.98 mV, respectively. The in vitro dissolution was studied, and the two dry powders showed a significant increase compared to silybin. The two dried powders had better long-term stability than the liquid starting material. Overall, spray-drying and freeze-drying are appropriate drying methods for the preparation of silybin nanosuspensions with better stability and dissolution velocity.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1695
Author(s):  
Nicole Härdter ◽  
Tim Menzen ◽  
Gerhard Winter

Primary containers made of cyclic olefin polymer (COP) have recently gained attention since they may overcome several risks and shortcomings of glass containers as they exhibit a high break resistance, biocompatibility, and homogeneous heat transfer during lyophilization. On the downside, COP is more permeable for gases, which can lead to an ingress of oxygen into the container over time. Since oxidation is an important degradation pathway for monoclonal antibodies (mAbs), the continuous migration of oxygen into drug product containers should be avoided overall. To date, no long-term stability studies regarding lyophilizates in polymer vials have been published, potentially because of the unbearable gas permeability. In this study, we demonstrate that after lyophilization in COP vials and storage of these vials in aluminum pouches together with combined oxygen and moisture absorbers (“smart packaging”), oxidation of two lyophilized therapeutic antibodies was as low as in glass vials due to the deoxygenated environment in the pouch. Nevertheless, active removal of oxygen from the primary container below the initial level over time during storage in such “smart” secondary packaging was not achieved. Furthermore, residual moisture was controlled. Overall, the smart packaging reveals a promising approach for long-term stability of biopharmaceuticals; in addition to COP’s known benefits, stable, low oxygen and moisture levels as well as the protection from light and cushioning against mechanical shock by the secondary packaging preserve the sensitive products very well.


1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.


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