This site is intended for health professionals only

Published on 1 September 2007

Share this story:
Twitter
LinkedIn

Titanium tetrachloride as drug vapour simulant: a response

teaser

James A Jorgenson
RPh MS FASHP

Administrative Director for Pharmacy Services
Associate Dean/Associate Professor for Pharmacy
University of Utah Health Sciences Center
Salt Lake City
Utah
USA

 

This is in response to the Sponsored Profile by Teva Medical Devices published in your March/April issue.(1)

In this promotional article, Teva disputes the validity of the independent test conducted at the University of Utah to determine which commercially available drug transfer systems meet the NIOSH and ISOPP definitions of “closed”.

The study in question was performed by Cam Au PharmD, a pharmacy practice resident at the ­University of Utah, and Bart Smith, a senior pharmacy student at the University of Utah, as part of their elective management rotation, which I supervised.

Despite personal communication with Teva ­regarding our study, they have misinterpreted, hence misrepresented, how the test was performed with respect to the movement of the “smoke”. As I ­confirmed with Teva prior to the release of the article, the smoke particles are actually larger than the filter pores and will quickly clog the filter, and did so in our test. It is not the smoke that is exiting the system; it is the titanium tetrachloride particles themselves (thus the emphasis on the particle size). These particles are smaller than the filter pores, and when they exit the system they immediately react with the moisture in the air to form the visible smoke. There are actually two smoke components – the smoke you see in the vial and that which you see outside the vial. I have included a schematic showing this process (see Figure 1).

[[hpe34_fig1_13]]

Overall this was a very simple study designed to see which commercially available drug transfer ­systems were indeed “closed”. As defined by the US National Institute for Occupational Safety and Health (NIOSH) and endorsed by the International Society of Oncology Pharmacy Practitioners (ISOPP), a closed-system drug transfer device is “a drug transfer device which mechanically prohibits the transfer of environmental contaminants into the system and the escape of hazardous drug or vapor concentrations outside the system”. ISOPP, in its proposed guidelines, also includes the further clarification that the system should be “leakproof and airtight”. As ISOPP points out, “either a system is closed or it is not”. Since the titanium came out of the Tevadaptor, it is clearly not closed. Teva’s own Ministry of Health determined that the Tevadaptor system was not considered closed. Quoting from an official communication supplied by the Israeli Ministry of Health: “Tevadaptor is not a closed system for handling of hazardous drugs.”

Teva appears to want to deflect attention away from the study outcome and focus on the material used for the smoke. This is totally irrelevant. If the ­titanium came out of the Tevadaptor, then by definition it is not closed. End of story. As long as the smoke or the particles did not damage the filter in any way (which they did not, as confirmed by an independent testing laboratory), it doesn’t matter what material is used for the test.

Clearly the Teva system is not airtight. If Teva would like to test their system with an organic ­material, you can repeat this experiment using isoamyl acetate in place of the titanium tetrachloride. This compound is used to fit test respiratory equipment and is approved by the US Occupational Safety and Health ­Administration for this purpose. It gives off a very strong banana-like odour. If you can detect the odour, then the respirator has failed. Upon pressurising the Teva system, you can immediately smell the product outside the system, again indicating the Teva system is not closed. Only one system tested, the PhaSeal system by Carmel Pharma, met the NIOSH and ISOPP definition of “closed”.

The question remains as to whether the ­charcoal filter mechanism actually works in practice to trap ­hazardous drug vapour. Teva points out that the ­system has been studied successfully with four ­different drugs. I would like to point out that these are internal studies conducted by Teva in a l­aboratory and do not represent real practice settings. As both ASHP and ISOPP indicate, studies should be ­conducted in real practice settings and published in peer-reviewed scientific journals to be of any validity.

“Data on file” at Teva emphatically does not ­constitute scientific evidence of the effectiveness of this system. Teva has a long way to go to create a body of scientific evidence that demonstrates their product is airtight and leakproof, and all the “infomercials” they want to pay for will not change the fact that the Tevadaptor system is not closed and they have no peer-reviewed, published studies demonstrating its effectiveness in real practice.

Reference
1. Teva Europe. Titanium chloride smoke as drug vapour stimulant – a critique. HPE 2007;31:34.

Your comments: (Terms and conditions apply)

Of course I agree with Professor Jorgenson. I fail to see the problem: if something or anything escapes a system, that system obviously is not closed. – Name and location supplied



Most read




Latest Issue

Be in the know
Subscribe to Hospital Pharmacy Europe newsletter and magazine
Share this story:
Twitter
LinkedIn