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Maxim Hurwicz's avatar

If you get interested in this sort of thing take a gander at 10% crotamiton (Eurax) cream.

GoodRx says it is a prescription medicine going for a mere $600 for a 2 oz tube (60 mL) in the good ol' USA while in the UK it is over-the-counter and $8 for a 3.4 oz tube (100 mL).

We need a 1000% tariff on that pesky UK stuff or we can never ever compete!!!

Maxim Hurwicz's avatar

The winding road to spinosad approval (as Natroba™) is as interesting as they comes.

The first FDA applications specified spinosad in a lotion containing benzyl alcohol.

https://www.fda.gov/media/80089/download

The FDA states in that record,

"FDA agrees that spinosad, containing spinosyns A and D in a ratio of approximately 5:1, is a single active ingredient. However, we have recently approved a product [Ulesfia, discontinued in 2019] containing benzyl alcohol (present at 5%) as an active ingredient for the treatment of head lice. This would indicate that your product contains two active ingredients: spinosad and benzyl alcohol"

Nowhere can I find what percent of benzyl alcohol is present in Natroba, but it specifically is not for under certain ages.

As far as I can tell, the FDA wanted to know if benzyl alcohol was an active ingredient in treating head lice. I don't fully understand all the ins and outs here, but companies seem to get some sort of monopoly on new, unique medicines and lo and behold someone had already gotten approval of a treatment with 5% benzyl alcohol. Can't be handing out a new medicine that steps on the toes of an already granted approval, I guess. As I say, I am no expert, not a doctor or chemist, just the son of a Nobel winner and there is not even a shadow of evidence that bequeaths any expertise. "No kings" should be the motto with Nobel Prize winners, thus no princes either, I guess. In pursuing this thread I am more like one of the 7 blind men trying to feel and elephant and declare what "it" is. I wish some disinterested expert would contribute their two cents worth.

A large portion of the FDA application is focused on whether the benzyl alcohol is safe for infants, especially 0 to 6 months. In fact the report states,

"The minimum amount of benzyl alcohol at which toxicity may occur is not known. Premature and low-birthweight infants, as well as patients receiving high dosages, may be more likely to develop toxicity"

Further,

"Benzyl alcohol used as preservative in saline flush solutions has been associated with 16 neonatal deaths."

Here is another reference on that "Neonatal Deaths Associated With Use Of Benzyl Alcohol" at https://www.cdc.gov/mmwr/preview/mmwrhtml/00001109.htm

Oh no says the applicant, we don't need it as an active ingredient. It is a preservative and "The

applicant states that benzyl alcohol is preferred because it is a USP/NF ingredient"

It is notable that USP/NF only indicates quality in terms of product identity, purity, potency, and performance…nowhere do I see safety.

And please excuse us from having to expensive and difficult testing on infants and babies as,

"Under 21 CFR 314.55(c)(3)(i) the applicant requests a waiver of pediatric research in

infants 0 to 6 months of age.

The reasons given were that

a) Studies are highly impractical or impossible

b) The product fails to represent a meaningful therapeutic benefit over existing therapies

for pediatric patients and is unlikely to be used in a substantial number of patients in

these age groups. "

Isn't that cute? They are expressly stating their product is no better than existing products for children!

Imagine, if it were better than existing therapies, then would testing on young u's be worthwhile? Where is the logic in these arguments or justifications?

And "Golly jee, Massah FDA, doin' all dat hard testing is jess impracticable…damnation dat's a hard word! Whut's dat woid mean anyways?"

Long story short, Natroba managed to declare the benzyl alcohol an inactive ingredient and snatched approval from the jaws of disapproval by this bit of tap dancing.

The spinosad I carry does NOT contain benzyl alcohol so it is not equivalent to Natroba, thank goodness. And as far as I can discern, as no kind of expert or authority or PhD'd sort, the other ingredients are not only inactive, but also inert…and are effective if feedback is any metric.

To my untrained mind it is fascinating that if one looks at the results of the two tests Natroba presented here: https://www.natroba.com/scabies/efficacy/

the spinosad + vehicle cured 69% to 83% of patients and the vehicle alone cured 34% to 46% of patients. As far as I can tell "vehicle" means whatever they are stirring the spinosad into the lotion I guess.

Wait a minute. The vehicle is curing some folks…more than just a few, too, it's curing a third to almost half of patients. Without an active ingredient it is some sort of magic stuff?

How can the vehicle cure anyone if it doesn't have an active ingredient? The mind boggles. And they don't provide any testimony as to the percentage of benzyl alcohol in their vehicle. Would a bit more inactive ingredient make the vehicle as effective as spinosad alone or spinosad plus BA?

It makes me wonder if the Emperor not only has no clothes, but no royal private parts either.

I doubt this really answers your question why it has taken so long for someone to make spinosad available. It is a combination of oddities. And me hearing the haunting tune "Fools Rush In" (complete with syncopated congos) as an ear-worm when I launch into new projects.

As an aside, benzyl benzoate is my other scabies treatment product and it is not a prescription medicine, amazingly enough (according to Drugs.com). As a lotion it has been in use for a long time and yet I am the only source in the USA for this. Of course I don't sell this stuff as a medicine, but people are free to use it as they will if they take personal responsibility for the results. In the past I suspected being tiny and below the radar might have been the charm in terms of the FDA's enforcers not knocking on my door, but now, what with the FDA's radar being dismantled, I can exhale for a while.

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