Crosswords1 min ago
Crotamiton, How Discovered/invented?
I use a cream containing crotamiton to deal with general itchiness caused by rashes, bites, dry skin and so on. Being of an enquiring mind, I searched on the net to find out what crotamiton is and how it works, because it works AMAZINGLY well. Apparently as well as being generally good at managing itchiness, it also can be used to treat scabies.
My question is this. So far as I can find online, the way it works, either to treat scabies or manage itchiness is unknown and there seems to be no information available about how is is synthesized or derived, who discovered or developed it or how it was discovered or developed.
So 1, does anyone have any further info?
and, more generally
2, if you don't know how something works, how would you go about discovering or developing it?
My question is this. So far as I can find online, the way it works, either to treat scabies or manage itchiness is unknown and there seems to be no information available about how is is synthesized or derived, who discovered or developed it or how it was discovered or developed.
So 1, does anyone have any further info?
and, more generally
2, if you don't know how something works, how would you go about discovering or developing it?
Answers
woofgang, in the absence of any real info on its use in itchiness, I think it's possible that somewhere, sometime, someone spilt crotamiton oil on an itchy part of their skin and noticed its antipruritic properties. Emulsifying the oil and adding excipients is a small step from there although it probably cost a few bob to go through trials before being...
21:22 Wed 18th Mar 2015
Ah good old N-ethyl-N-(o-methylphenyl) -2-butenamide. The name rolls off the tongue but the pure oil needs a wide label on the bottle! In a laboratory, the substance is sometimes labelled with its official IUPAC name,
N-ethyl-N-(2-methylphenyl)but-2-enamide.
The oil is insoluble in water but is soluble in the majority of alcohols. The pure product is usually colourless but can have a yellowish tinge due to impurities that are sometimes introduced during synthesis.
Crotamiton is an Aniilide, which are organic compounds made from other organic compounds called oxoacids. What happens in very simple terms is that part of the structure of certain oxoacids are removed an added to a very unpleasant chemical called aniline. Aniline itself has a huge number of industrial uses from rubber manufacture, dyes, paracetamol and weed killers to name but a few.
Crotamiton can indeed kill the scabies mite but it's not as effective as more modern treatments. Crotamiton cream application to scabies infestations can have a success rate of as low as 50%, which is not really that good. I do appreciate that you have found it amazingly good, but there's statistics for you!
As far as its mechanism of action is concerned as a scabicide or antipruritic, no one really knows. It is possible to follow certain key steps of the behaviour of the compound at a biochemical level via key insect metabolism pathways, but I'm afraid that we come to a dead end at one very important metabolic stage. Why it works as an antipruritic has never been explained in the scientific press properly and again, no one really knows.
As biochemist with some knowledge of toxicology, I know that crotamiton is structurally closely related to a number of compounds found in nature that are quite toxic and I've a fair idea of the mechanism of action based upon their structure. I'm afraid though that it's much too complex a theory to put forward here.
N-ethyl-N-(2-methylphenyl)but-2-enamide.
The oil is insoluble in water but is soluble in the majority of alcohols. The pure product is usually colourless but can have a yellowish tinge due to impurities that are sometimes introduced during synthesis.
Crotamiton is an Aniilide, which are organic compounds made from other organic compounds called oxoacids. What happens in very simple terms is that part of the structure of certain oxoacids are removed an added to a very unpleasant chemical called aniline. Aniline itself has a huge number of industrial uses from rubber manufacture, dyes, paracetamol and weed killers to name but a few.
Crotamiton can indeed kill the scabies mite but it's not as effective as more modern treatments. Crotamiton cream application to scabies infestations can have a success rate of as low as 50%, which is not really that good. I do appreciate that you have found it amazingly good, but there's statistics for you!
As far as its mechanism of action is concerned as a scabicide or antipruritic, no one really knows. It is possible to follow certain key steps of the behaviour of the compound at a biochemical level via key insect metabolism pathways, but I'm afraid that we come to a dead end at one very important metabolic stage. Why it works as an antipruritic has never been explained in the scientific press properly and again, no one really knows.
As biochemist with some knowledge of toxicology, I know that crotamiton is structurally closely related to a number of compounds found in nature that are quite toxic and I've a fair idea of the mechanism of action based upon their structure. I'm afraid though that it's much too complex a theory to put forward here.
Turning to the issue of who discovered Crotamiton, aniline derived compounds have been well known to kill bacteria since the 17th century, when aniline was first isolated. It's not unusual for scientists to take a known toxic chemical to mammals and move on to check its toxicity to bacteria, fungi and viruses. This is exactly what happened with aniline.
In the human body, when aniline is ingested it poisons haemoglobin. This causes iron to leach from red blood cells and a substance called methemoglobin to form. Methemoglobin cannot carry oxygen and a type of dangerous anaemia develops along with spleen inflammation. There are documentated cases of of such aniline deaths and all this may have played a part too.
Crotamiton can be regarded as a derivative of aniline so this is probably how it all started.
Your final sentence is a huge question. I'm on digoxin tratment for a cardiac condition called atrial fibrillation. Digoxin is derived from Digitalis, a powerful very toxic alkaloid present in the foxglove. I often think who it was that noticed that a sub-toxic dose of the foxglove plant altered the heart rhythm. Someone must have done it at some point for it to be used in this manner. Who,why,where or when we'll never know.
There's is also another angle here. Take homeopathy where very small doses of toxic substances are used to treat diseases. I'm not a fan of homeopathy but there are people who swear by it including apparently horses who recover from diseases and have no axe to grind over effectiveness. Who first thought of homeopathy? How many have died along the way by taking arsenic salts, a common homeopathic therapy, when the toxic dose was unknown?
It's certainly food for thought.
In the human body, when aniline is ingested it poisons haemoglobin. This causes iron to leach from red blood cells and a substance called methemoglobin to form. Methemoglobin cannot carry oxygen and a type of dangerous anaemia develops along with spleen inflammation. There are documentated cases of of such aniline deaths and all this may have played a part too.
Crotamiton can be regarded as a derivative of aniline so this is probably how it all started.
Your final sentence is a huge question. I'm on digoxin tratment for a cardiac condition called atrial fibrillation. Digoxin is derived from Digitalis, a powerful very toxic alkaloid present in the foxglove. I often think who it was that noticed that a sub-toxic dose of the foxglove plant altered the heart rhythm. Someone must have done it at some point for it to be used in this manner. Who,why,where or when we'll never know.
There's is also another angle here. Take homeopathy where very small doses of toxic substances are used to treat diseases. I'm not a fan of homeopathy but there are people who swear by it including apparently horses who recover from diseases and have no axe to grind over effectiveness. Who first thought of homeopathy? How many have died along the way by taking arsenic salts, a common homeopathic therapy, when the toxic dose was unknown?
It's certainly food for thought.
woofgang, in the absence of any real info on its use in itchiness, I think it's possible that somewhere, sometime, someone spilt crotamiton oil on an itchy part of their skin and noticed its antipruritic properties. Emulsifying the oil and adding excipients is a small step from there although it probably cost a few bob to go through trials before being marketed. Eurax Cream (Crotamiton) was once a prescription only medicine in the UK and US.
Events like this are often the case as I've seen similar discoveries happening in my own university laboratories over the years. Last month, one of my microbiology technicians made a mistake in mixing three growth mediums we needed for slime mould culture and created a substance which killed virtually all the bacteria we threw at it and believe me, we carry samples of a lot. The shame is that the substance doesn't stand a chance of eventually becoming an antibiotic!
Events like this are often the case as I've seen similar discoveries happening in my own university laboratories over the years. Last month, one of my microbiology technicians made a mistake in mixing three growth mediums we needed for slime mould culture and created a substance which killed virtually all the bacteria we threw at it and believe me, we carry samples of a lot. The shame is that the substance doesn't stand a chance of eventually becoming an antibiotic!
Thanks EDDIE51. I seem to be doing more and more work these days. Right now, I'm in Los Alamos visiting a nearby laboratory providing advice on RNA and very special enzymes. The weather is appalling but at least I'm not paying for my hotel room as I'm on campus. Hope to be back in England on Monday.
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