CEE consists of 50% to 70% estrone and 22% to 32% equilin
and 7 or more other poorly characterized estrogens, not found in the human female.
Additionally, in a recent review article by Zhao and Brinton (2006), coadministration of two of three neuroprotective estrogens (17 [beta]-estradiol, equilin
, and [DELTA]89-dehydroestrone) exerted a greater neuroprotective efficacy than individual estrogens in neurodegenerative insults through rat and human studies (Liqin Zhao, 2005) (Class 3).
One of them is equilin
, which is present in horses but not in women.
In Anne Walch's article, "Hormones and Menopause Revisited" Jun/July 04, the paragraph beginning "Premarin, also known as conjugated equilin
estrogen (CEE) .
Unlike synthetic estrogens, natural estrogens do not contain equilin
, a horse-derived toxic molecule found in synthetic hormones that has been found to cause damage to DNA cells in humans, according to published research.
Holtorf has replied that "evidence-based medicine does not mean that data should be ignored until a randomized trial of a particular size and duration is completed"--noting that estriol has been used for decades without reported safety concerns and that Premarin[R] contains the non-human estrogen equilin
sulfate, which promotes cancer.
Premarin, also known as conjugated equilin
estrogen (CEE), is derived from pregnant mare's urine.
However, Wyeth-Ayerst goes on to suggest that Duramed may not support its NDA with particular studies -- "animal and human clinical studies of other estrogens such as estrone, equilin
, or conjugated estrogens," id.
Unlike bioidentical estrogen creams that provide the hormones found naturally in the human female body, horse estrogen contains equilin
and other equine estrogens found exclusively in horses
These are: 1) that delta 8,9 DHES be required to be included in generic conjugated estrogens tablets at the level found in Premarin; 2) that delta 8,9 DHES be treated the same as estrone sulfate and equilin
sulfate, which FDA has indicated are the principal components in conjugated estrogens; and 3) that FDA require proper bioequivalence measurement studies to be conducted on any generic version of conjugated estrogens to prove that blood levels of delta 8,9 DHES in the generic product are the same as Premarin.
A science advisory panel met again in July of this year and confirmed the agency's long standing position that there was insufficient data to make a recommendation for inclusion of any ingredients other than the two established actives estrone sulfate and equilin
The advisory committees voted unanimously that there is insufficient data to assess whether any individual component (including delta 8,9 dehydroestrone sulfate) or combination of components other than estrone sulfate and equilin
sulfate need to be present to achieve clinical safety and efficacy in conjugated estrogens.