DEAR DR. GOTT: I’ve been a chemist and forensic scientist for more than 50 years, and in your column you address a woman’s questions regarding chronic vaginal inflammation and repeated yeast infections. Years ago, I had a legal case involving a woman who used Premarin cream packaged in metal-walled “toothpaste”-type tubes. Her complaints and symptoms were much the same as your reader’s. In working as her expert witness on that case, I opened up and examined the offending Premarin tubes she had used. What I found was a badly designed delivery system that could not fail to cause horrific injury to anyone that used the product down to its completely collapsed, scrolled-up endpoint.

Such tubes are made of soft metal-like zinc but with an internal layer of polymer plastic coating the interior surface to prevent metal contamination or any reactive ingredients from chemically reacting with the metal walls. The defect comes when the user squeezes and deforms the tube walls to such an extent that the internal plastic layer fractures into small chips and delaminates from its attachment to the wall. [Read more...]