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Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments

John Dingley, Nicholas Thatcher, David Williams

Anaesthesia

Abstract

We wished to know whether low melting point phase change waxes could be used in the manufacture of emergency drug transport bags to reduce the known temperature extremes their contents can be exposed to. We designed 2 custom made hollow-walled drug containers. These were placed within a pair of stan...

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Published in: Anaesthesia
Published: New Jersey, United States Wiley
URI: https://cronfa.swan.ac.uk/Record/cronfa48570
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first_indexed 2019-01-26T05:01:16Z
last_indexed 2019-06-20T20:45:35Z
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fullrecord <?xml version="1.0"?><rfc1807><datestamp>2019-06-20T14:56:25Z</datestamp><bib-version>v2</bib-version><id>48570</id><entry>2019-01-25</entry><title>Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments</title><alternativeTitle></alternativeTitle><author>John Dingley</author><firstname>John</firstname><surname>Dingley</surname><active>true</active><ORCID/><ethesisStudent>false</ethesisStudent><sid>1283ffdd09b091ec57ec3e235a48cfcc</sid><email>7f9d114220a1d772843c444d87f74f62</email><emailaddr>gvMON5Lx4ighs2xG/1WwmAgr5y2nBRz3haj4DmVVDsQ=</emailaddr><date>2019-01-25</date><deptcode>PMSC</deptcode><abstract>We wished to know whether low melting point phase change waxes could be used in the manufacture of emergency drug transport bags to reduce the known temperature extremes their contents can be exposed to. We designed 2 custom made hollow-walled drug containers. These were placed within a pair of standard drug transport bags and subjected to 3 day/night cycles including periods of direct radiant sunlight. The wall cavities of one contained air while the wall cavities of the other contained a paraffin wax with a melting point of 44-46&#xB0;C. This also had a high latent heat of fusion and so until fully melted, its temperature would not increase further. We collected 25,920 temperature data sets at 6 locations within and on the containers. We found that 97.8 % and 84.7 % of ampoule temperatures within the wax and air cavity containers respectively were within a target range of 15&#xB0;C to 40&#xB0;C over the study duration (Levene statistic W = 4 279.1; Levene&#x2019;s test for equality of variance, p &lt; 0.001). Ampoule temperatures in the wax-cavity container only exceeded 40&#xBA;C for 1.7 % of the time. Even when they did so, their temperature was limited to a peak of to 40.3&#xBA;C, despite an ambient air temperature of &gt;40&#xBA;C for 6.4 % of the time (peak 46.9&#xBA;C) and a bag surface temperature of &gt;40 &#xBA;C for 17.2 % of the time (peak 64.4&#xBA;C). In contrast, the ampoule temperature in the air-cavity container exceeded 40&#xBA;C for 17.1 % of the time with a peak value of 54.1&#xBA;C. We concluded that the latent heat of fusion of phase change materials may be exploited in the design of drug transport bags to mitigate any temperature changes of the drugs stored within them.</abstract><type>Journal article</type><journal>Anaesthesia</journal><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher>Wiley</publisher><placeOfPublication>New Jersey, United States</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Drug transport, Drug storage, Emergency Medical Team, Thermal stability.</keywords><publishedDay>0</publishedDay><publishedMonth>0</publishedMonth><publishedYear>0</publishedYear><publishedDate>0001-01-01</publishedDate><doi></doi><url></url><notes></notes><college>Swansea University Medical School</college><department>Medicine</department><CollegeCode>CMED</CollegeCode><DepartmentCode>PMSC</DepartmentCode><institution/><researchGroup>None</researchGroup><supervisor/><sponsorsfunders/><grantnumber/><degreelevel/><degreename>None</degreename><lastEdited>2019-06-20T14:56:25Z</lastEdited><Created>2019-01-25T21:26:53Z</Created><path><level id="1">Swansea University Medical School</level><level id="2">Medicine</level></path><authors><author><firstname>John</firstname><surname>Dingley</surname><orcid/><order>1</order></author><author><firstname>Nicholas</firstname><surname>Thatcher</surname><orcid/><order>2</order></author><author><firstname>David</firstname><surname>Williams</surname><orcid/><order>3</order></author></authors><documents/></rfc1807>
spelling 2019-06-20T14:56:25Z v2 48570 2019-01-25 Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments John Dingley John Dingley true false 1283ffdd09b091ec57ec3e235a48cfcc 7f9d114220a1d772843c444d87f74f62 gvMON5Lx4ighs2xG/1WwmAgr5y2nBRz3haj4DmVVDsQ= 2019-01-25 PMSC We wished to know whether low melting point phase change waxes could be used in the manufacture of emergency drug transport bags to reduce the known temperature extremes their contents can be exposed to. We designed 2 custom made hollow-walled drug containers. These were placed within a pair of standard drug transport bags and subjected to 3 day/night cycles including periods of direct radiant sunlight. The wall cavities of one contained air while the wall cavities of the other contained a paraffin wax with a melting point of 44-46°C. This also had a high latent heat of fusion and so until fully melted, its temperature would not increase further. We collected 25,920 temperature data sets at 6 locations within and on the containers. We found that 97.8 % and 84.7 % of ampoule temperatures within the wax and air cavity containers respectively were within a target range of 15°C to 40°C over the study duration (Levene statistic W = 4 279.1; Levene’s test for equality of variance, p < 0.001). Ampoule temperatures in the wax-cavity container only exceeded 40ºC for 1.7 % of the time. Even when they did so, their temperature was limited to a peak of to 40.3ºC, despite an ambient air temperature of >40ºC for 6.4 % of the time (peak 46.9ºC) and a bag surface temperature of >40 ºC for 17.2 % of the time (peak 64.4ºC). In contrast, the ampoule temperature in the air-cavity container exceeded 40ºC for 17.1 % of the time with a peak value of 54.1ºC. We concluded that the latent heat of fusion of phase change materials may be exploited in the design of drug transport bags to mitigate any temperature changes of the drugs stored within them. Journal article Anaesthesia Wiley New Jersey, United States Drug transport, Drug storage, Emergency Medical Team, Thermal stability. 0 0 0 0001-01-01 Swansea University Medical School Medicine CMED PMSC None None 2019-06-20T14:56:25Z 2019-01-25T21:26:53Z Swansea University Medical School Medicine John Dingley 1 Nicholas Thatcher 2 David Williams 3
title Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
spellingShingle Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
Dingley, John
title_short Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
title_full Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
title_fullStr Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
title_full_unstemmed Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
title_sort Use of phase change materials in emergency medical drug transport bags to reduce temperature variability in labile thermal environments
author_id_str_mv 1283ffdd09b091ec57ec3e235a48cfcc
author_id_fullname_str_mv 1283ffdd09b091ec57ec3e235a48cfcc_***_Dingley, John
author Dingley, John
author2 John Dingley
Nicholas Thatcher
David Williams
format Journal article
container_title Anaesthesia
institution Swansea University
publisher Wiley
college_str Swansea University Medical School
hierarchytype
hierarchy_top_id swanseauniversitymedicalschool
hierarchy_top_title Swansea University Medical School
hierarchy_parent_id swanseauniversitymedicalschool
hierarchy_parent_title Swansea University Medical School
department_str Medicine{{{_:::_}}}Swansea University Medical School{{{_:::_}}}Medicine
document_store_str 0
active_str 1
description We wished to know whether low melting point phase change waxes could be used in the manufacture of emergency drug transport bags to reduce the known temperature extremes their contents can be exposed to. We designed 2 custom made hollow-walled drug containers. These were placed within a pair of standard drug transport bags and subjected to 3 day/night cycles including periods of direct radiant sunlight. The wall cavities of one contained air while the wall cavities of the other contained a paraffin wax with a melting point of 44-46°C. This also had a high latent heat of fusion and so until fully melted, its temperature would not increase further. We collected 25,920 temperature data sets at 6 locations within and on the containers. We found that 97.8 % and 84.7 % of ampoule temperatures within the wax and air cavity containers respectively were within a target range of 15°C to 40°C over the study duration (Levene statistic W = 4 279.1; Levene’s test for equality of variance, p < 0.001). Ampoule temperatures in the wax-cavity container only exceeded 40ºC for 1.7 % of the time. Even when they did so, their temperature was limited to a peak of to 40.3ºC, despite an ambient air temperature of >40ºC for 6.4 % of the time (peak 46.9ºC) and a bag surface temperature of >40 ºC for 17.2 % of the time (peak 64.4ºC). In contrast, the ampoule temperature in the air-cavity container exceeded 40ºC for 17.1 % of the time with a peak value of 54.1ºC. We concluded that the latent heat of fusion of phase change materials may be exploited in the design of drug transport bags to mitigate any temperature changes of the drugs stored within them.
published_date 0001-01-01T05:47:56Z
_version_ 1637558283204034560
score 11.000887

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