The plasticizers in the three studies were evaluated in a number of different extraction media, but this article focuses on data from water, soapy water, and mineral oil tests to determine their relative extraction resistance. Hexane extraction has been included for reference purposes, even though it does not seem to be representative of any medical exposure medium. At present, DOP is the main plasticizer used for medical applications, but citrate plasticizers are being touted as lower-toxicity alternatives. Besides comparing DOP and citrates, this article tabulates data regarding trimellitate and polymeric plasticizer to demonstrate a wider range of extractabilities. When comparing Studies 1 and 2, the relative extractabilities of the common plasticizers DOP and DOA were used, whereas when comparing those two studies with Study 3, only the relative extractability of DOP was used.
Water is by far the least aggressive medium reviewed here.
It would appear that DOA, H-640, and the citrate plasticizers fall into the same range of extractability. By comparing their extractability with that of DOP and DOA from Studies 1 and 2, a relative extraction resistance ranking can be made for the other plasticizers. Soapy water is a far more aggressive medium than water. The proteins in plasma are reported to have a similar effect. Based on extraction studies, trimellitates are a good choice if the desired outcome is to reduce the amount of plasticizer that is extracted from a flexible PVC medical device by a variety of media.