I just gave blood. As the red stuff was trickling out, I began to wonder about Betadine–the antiseptic they swab all over your skin to sterilize it before they stick you.
Is the yellow color an inherent part of whatever chemicals Betadine is made of? Or is it a dye added to aid in visibility (so you know what you’ve cleaned)?
It does contain iodine, so that may be where the color comes from. However, I also recall reading somewhere that it is effective as long as you can see the color, so perhaps it serves some purpose as well.
I’m pretty sure the color (which is the color of iodine) is from the active ingredient, an iodine compound called “povidone iodine.” However, although I’m pretty sure they don’t add any dye to it, I am convinced that the color contributes to its popularity. I think people like to see their skin stained brown. The patient knows medicine has been applied and the health care provider knows medicine has been applied.
The reason I think the color contributes to povidone iodine’s popularity is that there has been available in the U.S. for at least 20 years another topical disinfectant, chlorhexidene gluconate (the active ingredient in Hibiclens and other preparations), that is IMHO superior to povidone iodine yet you still see povidone iodine used everywhere. Hibiclens is red (presumably becuase of the addition of a coloring agent) but IT DOES NOT DYE THE SKIN. I’m convinced the main reason people still use povidone iodine is that they like to see the skin turn yellow!
A diversionary question of semantics:
“Dye” is not one of the basic elements that make up the natural world. Something is a dye if it’s used as a dye. If betadine is used to impart color, as the above poster suggested, then it is itself ipso facto a dye.
Also, some medicines work exactly because they are dyes. Layman’s vague memories of how it works here: some dyes bond so strongly with the dyed material that, in the case of living tissue, they actually bond with and interfere with the DNA, thus messing it the hell up. Malachite Green and, IIRC, Gentian Violet are two dyes that are used as anti-protozoan agents. Having had this property of some dyes explained to me by a vet when I worked in a pet store, I have long assumed that betadine worked in a similar way.
Can anyone explain to me where I’m wrong and where, if at all, I’m right?
Thanks.
Sorry. More precisely:
Do one or more of the ingredients that allow betadine to disinfect also impart a yellow color to human skin, or is an additional substance that is not necessary for betandine’s primary function, i.e., disinfection, added to the product in order to create the yellow color?
The relationship between dyes and antibiotics is fascinating. Before “modern” chemistry, most drugs were derived from minerals or plants (e.g., the antimalarial quinine from tree bark). The development of modern antibiotics was closely tyed to the the efforts of chemists trying to make synthetic dyes superior to (or at least cheaper than “natural dyes”). I had thought that antibiotics were the results of unsuccessful attempts to create dyes but apparently things went both ways. Here is just a bit of a very interesting article in Brintannica DVD 2000: “William H. Perkin, in England, made the first aniline dye (1856) as a result of abortive attempts to synthesize quinine, the sole antimalarial drug available at that time. About 30 years later, Ehrlich found that a synthetic dye, methylene blue, has antimalarial properties. He had been led to this by a study of the specific staining of organs of an animal or of a parasite following the injection of a synthetic dye. From these studies there emerged (1901-04) Ehrlich’s well-known “side-chain” theory, in which he sought for the first time to correlate the chemical structure of a synthetic drug with its biological effects. In 1903 Ehrlich invented a dye, trypan red, which was the first drug to show activity against trypanosomal infections in mice. Ehrlich’s greatest triumph, however, was the discovery (1910) of the organic arsenical drug Salvarsan, which proved to be effective in the treatment of syphilis. The discovery of other chemotherapeutic agents followed, including mepacrine, proguanil, and chloroquine.”