http://www.latimes.com/news/nationworld/washingtondc/la-na-fda15mar15,1,5035088.story Edited to add: Meant to put this in Health, oops. Anyway, it is interesting enough that I am leaving it, if only because of the responses I would get to "delelte".................
And the story DOES say the substance is mysterious!! So there!!
FDA officials said they are close to identifying the mysterious look-alike ingredient that contaminated the Baxter heparin and prompted a recall last month. The substance, which acts much like heparin, could not be detected with conventional tests for drug purity and potency.
Once the contaminant is identified, investigators should be able to tell more about whether it was deliberately added or occurred naturally, or as a result of some problem with processing, FDA Deputy Commissioner Janet Woodcock said.
"We are very close," she said. "When we complete that, will help our understanding of how it got in."
However, pinpointing the source may not be possible if the contamination occurred along the chain of farmers and middlemen who handle the material in China, where the FDA's regulatory reach does not extend and where manufacturing standards have been called into question.
FDA officials said they have visited some of the middlemen -- called "consolidators" -- to discuss the quality of materials received from slaughterhouses. Consolidators refine the material and prepare it for shipping to a pharmaceutical facility in Changzhou. FDA officials said they are trying to arrange with Chinese authorities for additional inspections of the supply chain.