| Title |
Improving Heat Transfer at the Bottom of Vials for Consistent Freeze Drying with Unidirectional Structured Ice
|
|---|---|
| Published in |
AAPS PharmSciTech, October 2015
|
| DOI | 10.1208/s12249-015-0437-3 |
| Pubmed ID | |
| Authors |
Mónica Rosa, João M. Tiago, Satish K. Singh, Vítor Geraldes, Miguel A. Rodrigues |
| Abstract |
The quality of lyophilized products is dependent of the ice structure formed during the freezing step. Herein, we evaluate the importance of the air gap at the bottom of lyophilization vials for consistent nucleation, ice structure, and cake appearance. The bottom of lyophilization vials was modified by attaching a rectified aluminum disc with an adhesive material. Freezing was studied for normal and converted vials, with different volumes of solution, varying initial solution temperature (from 5°C to 20°C) and shelf temperature (from -20°C to -40°C). The impact of the air gap on the overall heat transfer was interpreted with the assistance of a computational fluid dynamics model. Converted vials caused nucleation at the bottom and decreased the nucleation time up to one order of magnitude. The formation of ice crystals unidirectionally structured from bottom to top lead to a honeycomb-structured cake after lyophilization of a solution with 4% mannitol. The primary drying time was reduced by approximately 35%. Converted vials that were frozen radially instead of bottom-up showed similar improvements compared with normal vials but very poor cake quality. Overall, the curvature of the bottom of glass vials presents a considerable threat to consistency by delaying nucleation and causing radial ice growth. Rectifying the vials bottom with an adhesive material revealed to be a relatively simple alternative to overcome this inconsistency. |
X Demographics
The data shown below were collected from the profile of 1 X user who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United States | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 32 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 32 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 6 | 19% |
| Researcher | 5 | 16% |
| Student > Bachelor | 3 | 9% |
| Student > Doctoral Student | 2 | 6% |
| Professor | 2 | 6% |
| Other | 4 | 13% |
| Unknown | 10 | 31% |
| Readers by discipline | Count | As % |
|---|---|---|
| Pharmacology, Toxicology and Pharmaceutical Science | 7 | 22% |
| Chemical Engineering | 4 | 13% |
| Engineering | 4 | 13% |
| Biochemistry, Genetics and Molecular Biology | 3 | 9% |
| Chemistry | 2 | 6% |
| Other | 2 | 6% |
| Unknown | 10 | 31% |
Attention Score in Context
This research output has an Altmetric Attention Score of 13. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 23 December 2021.
All research outputs
#2,769,252
of 25,436,226 outputs
Outputs from AAPS PharmSciTech
#54
of 1,591 outputs
Outputs of similar age
#37,913
of 295,289 outputs
Outputs of similar age from AAPS PharmSciTech
#1
of 34 outputs
Altmetric has tracked 25,436,226 research outputs across all sources so far. Compared to these this one has done well and is in the 89th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,591 research outputs from this source. They receive a mean Attention Score of 4.2. This one has done particularly well, scoring higher than 96% of its peers.
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We're also able to compare this research output to 34 others from the same source and published within six weeks on either side of this one. This one has done particularly well, scoring higher than 99% of its contemporaries.