Transbuccal use of Estrace: support for the efficacy of this delivery method

There are a fair number of women about the world today taking their HRT by the transbuccal route. Nonetheless, there are still doctors who do not believe that this is a viable route, especially for retail drugs like Estrace or Elleste Solo (available in the UK), since this is not listed as an approved delivery route on the medicine data sheet. Since the manufacturers have never bothered to test and obtain licensing approval for the use of this route, it can't be listed.

But that's not the same thing as not working. So when you ask your doctor about taking transbuccal hrt, you may have to prove your case. Here's what has helped some women in this situation.

It's a problem finding explicit references for this—the original ones that first suggested the idea to us are long gone from the internet and they were, in fact, barely more than passing mentions which we seized on as clues. As we recall, the premise was that compounded estradiol troches were a valid use because they were the same ingredient as Estrace, and that had been demonstrated to be effective when taken sublingually. We also know that nasal spray estradiol has long been used in research studies because it's such a reliable delivery. That kind of product is not offered commercially, alas, but because oral and nasal linings are structurally the same, that again argues for the physical possibility of uptake.

What we need to do is reason in the other direction, now, by analogy, and while that sounds iffy, it's really pretty straightforward. It goes like this:
The compounding pharmacies are using micronized estradiol to formulate their troches and oils that are made up for transbuccal use. There is adequate documentation in the professional literature that this route does deliver adequate circulating levels of hormonal agents when prepared in micronized form (that only refers to the size of the molecule, but that's what makes it capable of penetrating the skin and that's why things in larger molecular size, like premarin and CEEs, cannot be delivered by this route). Estradiol is micronized estradiol in brand name form; numerous generics exist as well. Estrace (and its generics) and Elleste Solo are readily soluble and those solubility figures can be provided by a pharmacy getting in touch with a particular manufacturer.

That estradiol is deliverable transbuccally is demonstrable (even though these particular studies were not specifically to test its efficacy as a delivery route, the fact that they caused measurable increase in serum estrogen levels does support the premise that this is a valid delivery route for estradiol) and you may provide your physician with this list of references; more are undoubtedly searchable at PubMed:

• "Sublingual administration of micronized estradiol and progesterone, with and without micronized testosterone: effect on biochemical markers of bone metabolism and bone mineral density"
• "Ação do estradiol sublingual na vasomotilidade coronária dependente e independente do endptélio em mulheres menopausadas portadoras de síndrome X" (scroll down to #014; abstract is in Portugese)
• "The acute effects of sublingual estradiol on left ventricular diastolic function in normotensive and hypertensive postmenopausal women"
• "The acute effects of sublingual 17beta-estradiol on the cardiovascular system"
• "Bioequivalence of a 17 beta-estradiol hydroxypropyl-beta-cyclodextrin complex in postmenopausal women"
• "Pharmacokinetics of estradiol, progesterone, testosterone and dehydroepiandrosterone after transbuccal administration to postmenopausal women"
• Sublingual Mucosa as a Route For Systemic Drug Delivery

One woman we know reported the conversation with her doctor on this topic as initially producing considerable skepticism. He looked over the info she emailed him, though, and talked to some pharmacists, and eventually told her that while he liked the sound of Estrace and thought it a great hrt, he wasn't totally convinced of how much got absorbed transbuccally (as opposed to swallowed). He ultimately said, she reported, that he was fully convinced it was going to get into her system one way or another if she put it in her mouth, so as long as she was happy with the coverage she was getting from her dose amount, he didn't see any reason to quibble with what she chose to do with it between bottle and circulatory system.

And then there is a body of anecdotal evidence from women using it this way who have had enough experience with various HRTs and menopausal symptoms to distinguish effective from ineffective, but of course, we know that this is highly unscientific and unreliable since we are *ahem* easily misled by treatment that successfully alleviates our symptoms.

Of course there's another approach to taking transbuccal hrts, and that's to take home a prescription for oral Estrace or Elleste Solo, adjust the dose for the change in route, and simply take it transbuccally. We wouldn't tell you to do that. But we can tell you it works.