See below. International unit dosing is the only way I see to sell some of
these compound classes without ridiculously expensive and needless separtion
and clean-up procedures.
Scott C.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
> Behalf Of Dennis Brownridge
> Sent: Saturday, December 02, 2000 3:22 PM
> To: U.S. Metric Association
> Subject: [USMA:9505] Re: International Unit
>
>
> Rowlett's dictionary of units reports that, for "standard preparations," 1
> IU =
>
> 0.3 µg of vitamin A
Vitamin A occurs in two principal forms in nature: retinol, which is found
only in animal sources, and certain carotenoids, the best known of which is
beta-carotene. beta-Carotene can be converted to retinol in the body. So if
you were selling pure retinol you could probably sell by the mg/dose, but if
you are selling a mixture of carotenoids, each with its own convertion to
retinol efficiency you wouldn't really be able to sell by mass/dose.
> 50 µg of vitamin C
Is one compound, ascorbic acid, so is usually sold as mg/tablet.
> 25 ng of vitamin D
Vitamin D is the generic name for a group of steroid-like substances with
anti-rachitic activity. It is found only in animals. The two most prominent
members of this group are ergocalciferol (vitamin D2) and cholecalciferol
(vitamin D3).
> 0.66 mg of vitamin E
Vitamin E is the collective name for various tocopherols and tocotrienols.
The most active form is of vitamin E is alpha-tocopherol.
> 45.5 µg of insulin
Is a large protein hormone made these days by fermentation with
bioengineered bacteria or yeasts, so in addition to those 45.5 µg, activity
also depends on whether some of the hormone has lost its structural
integrity during clean up, and what other inactive protein fragments may be
present. Weighing the extract would not tell that. They may use diabetic
animals to test the response and establish the activity of a batch, and this
would be given in international units/dose.
> 0.6 µg penicillin
Is an antibiotic of specific structure, so should be sold by mg/dose. The
structure has been tweeked chemically to counteract bacterial resisitance,
but these are given different names, eg Ampicillin, Amoxicillin, etc.
