Sublingual absorption of micronized 17/3-

ANDRE M. BURNIER, M.D. PURVIS L. MARTIN, M.D. SAMUEL S. C:. YEN, M.D. PATRICIA BROOKS, R.N.

La Jolla, Cnlifhziu

The sublingual absorption rates, the sustained effects, the biologic activity, and the metabolism of micronized 17p-estradiol (E2) were measured in 10 postmenopausal women. E2 (0.5 mg) was administered in a single sublingual dose to five of the patients. An alternate-day schedule with the same dosage was used for the other five patients. In the single-dose study, a twenty-six fold increase in serum E, and a ninefold increase in serum estrone (E,) concentrations were observed 1 hour after the sublingual deposition of E2 (0.5 mg). Serum concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were significantly decreased within 6 hours. The rise in E2 was early and peaked in the first 2 hours. The rise in E, was slower and progressive, reaching its maximum thirteenfold increase at 4 hours, and remained two and one half times the baseline of 29 pglml at 24 hours, whereas Ez returned to the baseline level of 24 pglml. When micronized E2 was given in a dosage of 0.5 mg subfingually every other night, increased circulating levels of continued to be elevated at a minimum two and one-half fold baseline level for the week of study. (AM. J. OBSTET. GYNECOL. 140:146, 1991.)

THE MICRONIZED form of i7@-estradiol (E,) in a serum follicle-stimulating hormone (FSH) and luteiniz- daily dose of 0.2 mg in a cream vehicle has been shown ing hormone (LH), and its metabolism as evaluated by in recent studies by Martin and associates’ to be more its conversion to E,. rapidly, completely, and physiologically absorbed from the vagina than from the oral route. Levels of E, in the Material and methods blood which are normal for the follicular phase of Ten healthy postmenopausal women between the premenopausal women with regular cycles are rapidly ages of 55 and 65 volunteered for this study. informed reached and sustained by postmenopausal women on consent was obtained from each woman. All prior es- daily vaginal cream therapy, with minimal trogen therapy had been withdrawn for a minimum of conversion to estrone (Et). 1 month. All subjects showed clinical evidence of en- The alternate sublingual route of administration of dogenous estrogen deficiency, all with vaginal atrophy micronized E, was tried clinically, with good response and some with vasomotor flushes that appeared after in the relief of menopausal symptoms, but there is a estrogen therapy was withdrawn. dearth of information in the literature concerning its Two groups were formed. The first group of five absorption by that route. patients comprised a single-dose study and received 0.5 The present report undertakes to fill this gap by de- mg of micronized E, sublingually (one-half tablet of termining the rate and the degree of absorption of commercially available Estrace 1 mg). The women re- sublingually administered Ez as indicated by its serum ported to the clinic at 8 AM on a Monday, levels, its biologic activity as reflected by suppression of had a baseline sample of blood drawn, and were given sublingually a 0.5 mg (one-half) tablet of Ez. Samples of blood were obtained 1, 2, 4, 6, 8, 10, and 24 hours after From the Department of Reproductive Medicine, School of complete disappearance of the half tablet, and again on Medicine, University of Califmia, San Diego. days 7, 14, 2 1, and 28. The half tablets of micronized E, Presented $ invitation at the Forty-seventh Annual were found to dissolve and disappear within 1 to 2 Meeting of the Pacific Coast Obstetrical and Gynecological Society, Monterey, California, October 6-1 I, 1980. minutes when placed under the tongue. Reprint requests: Andre M. Burnier, M.D., 550 The second group of five patients formed the Washington St., San Diego, California 92039. alternate-day study. The women reported at 8 AM on a

146 OOOZ-9378/81/100146+05$00.50/0 0 1981 The C. V. Mosby Co. Volume 140 Sublingual absorption of micronized E2 147 Number 2

Table I. Serum estrogen and gonadotropin concentrations prior to and after sublingual absorption of half a tablet containing 0.5 mg of micronized l’la-estradiol (0.5 mg Estrace-single-dose study)

Estnme* (pglml) 17PEstradioP (pglml) FSH* (mIUlm1) LH* (mIUlm1)

Pretreatment controls 29.0 + 5.5 23.4 k 5.6 92.2 rt 12.3 61.1 f 13.3 Time posttreatment 1 hr 270.4 k 78.3t 773.6 2 289.8$ 85.9 2 9.1 50.0 2 13.4$ 2 hr 346.6 f 93.9t 402.2 f 161.1$ 73.5 2 2.9 52.1 2 19.7 4 hr 384.8 2 89.9-f 133.4 zk 30.6t 76.0 f 11.4 41.5 f 13.6t 6 hr 378.0 k 73.lt 82.0 f lO.Ot 65.7 + 7.08 32.1 + 4.98 8 hr 302.2 k 37.3t 68.8 f 15.41 68.9 f 8.45 43.2 -c 7.2 10 hr 216.8 2 51.4t 47.6 f 6.05 84.4 k 13.9 49.0 2 12.2$ 24 hr 104.2 f 21.lt 24.4 k 2.2 82.1 k 11.4 52.9 " 5.4 1 wk 30.0 + 5.5 17.5 * 4.1 85.7 + 10.9 51.7 2 6.9 2 wk 30.6 f 4.7 16.0 f 2.5 93.7 k 14.4 53.3 f 6.9 3 wk 35.2 + 4.1 16.2 f 2.6 90.2 * 10.7 51.2 2 9.7 4 wk 36.4 + 5.1 22.6 f 6.5 84.8 + 8.5 46.4 + 3.9 *Mean f SE. tP < 0.01 (One-tailed t test). $P < 0.05 (One-tailed t test). $P < 0.025 (One-tailed t test).

Table II. Serum estrogen and gonadotropin concentrations prior to and after sublingual absorption of half a tablet containing 0.5 mg of micronized 17P-estradiol every other evening at 9 PM (0.5 mg Estrace-very other day)

Estrone* (pgiml) 17~EstradioP (pglml) FSH* (mIUld) LH* (miVld)

Pretreatment controls 19.0 + 4.5 12.4 ? 3.9 108.0 + 4.1 73.7 + 11.2 Day 1, 12 hr 192.2 f. 53.9t 50.4 2 8.6$ 84.6 " 6.3$ 54.5 k 13.49 Day 2, 36 hr 52.8 f 9.6t 36.6 + 18.4 102.6 + 19.9 71.3 + 12.2 Day 3, 12 hr 169.8 f 40.2t 29.8 f 6.0 104.3 f 19.8 76.5 f 12.7 Day 4, 36 hr 68.8 + 15.3$ 21.0 f 6.4 82.6 + 12.00 62.7 + 13.68 Day 7, 12 hr 206.8 zk 49.4$ 40.6 +: 10.88 96.9 +- 16.8 70.6 2 9.2 Day 14, 36 hr 56.8 f 14.7t 16.8 + 3.2 99.8 2 20.0 64.6 2 8.2 Day 21, 12 hr 190.8 + 47.3$ 58.6 f 17.50 84.6 + 16.5 53.7 f 8.5 *Mean 2 SE. tP < 0.025 (One-tailed t test). $P < 0.01 (One-tailed t test). $P < 0.05 (One-tailed t test).

Monday for the drawing of baseline samples of blood, levels were all in the normal postmenopausal range, and then were sent home after being given a 1 month with a significantly higher concentration of E, than Ez. supply of 0.5 mg of E2 (1 mg scored tablets precut in After the sublingual absorption of 0.5 mg of mi- half), with instructions to place half a tablet under the cronized Ez, there was a ninefold increase within 1 tongue at 9 PM of that same day, then every other day at hour in serum levels of E, and a twenty-six fold in- 9 PM-continuously for a month. Samples of blood crease in the levels of Ez. At 10 hours, the increase was were drawn 12 hours later at 9 AM, and every day at 9 eightfold for E, and only twofold for EP. At 24 hours, AM for 4 consecutive days, then at weekly intervals on the level of E, still showed a significant three and one- Monday at 9 AM, for 3 more weeks. half fold increase, whereas E2 had gone back to the Serum El, Ez, FSH, and LH were measured by radio- baseline level (Fig. 1). At 1 to 4 weeks, El, Ez, FSH, and immunoassays.*- LH all were in the pretreatment baseline range. Gonadotropin values were expressed as mlU/ml. Alternate-day study. Table II shows the mean levels All samples in a serial study were measured in a sin- of circulating El, Ez, FSH, and LH. Pretreatment levels gle assay. The data were analyzed statistically by the were also in the normal postmenopausal range, with Student’s one-tailed t test. higher concentrations of El than Ez. After the alter- nate-night sublingual absorption of 0.5 mg of micron- Results ized El, there was an average tenfold increase within 12 Single-dose study. Table I shows the mean levels of hours in serum levels of El, and a threefold increase in circulating El, E2, FSH, and LH; the pretreatment levels of Et, with a corresponding drop in FSH of 148 Burnier et al.

3200 Table III. Effect of sublingual absorption of Ei on 3000 cornified vaginal cells (‘% cornified cells, mean ? SE) 2800 Single dose of .4ltmkzte-duydosage vf 2600 0.5mgE,(N = 5) 0.5 mg E, (N = 5) 2400 Pretreatment 9.6 t 14.50 0 2200 At 28 days 0 53.4 + “3. I 2000 P < 0.005. 1800 I” 1600 and steadily increased, presumably through conversion 1400 f from E, to E,, reaching a peak at 2 to 4 hours and a v 1200 sustained, significantly higher level until 24 hours. 1000 % Thus, serum levels of E, and E2 were reached after : 800 sublingual administration of only 0.3 mg of micronized 400 E2 which compared closely with serum levels that fol- 400 lowed the oral administration of 2 mg of micronized EP. 200 four times the sublingual dose.” Early studies by Kyan 0 and Engel showed that the small bowel can convert IX2 to E,. Conversion also occurs when E2 is applied sublin- -10 gually, which suggests that another major pathway for -20 this metabolism also exists, possibly the reticuloen- -30 dothelial system. since the region of’ the neck is very -40 rich in lymphatic channels and lymphoid tissue. By- -50 -lWi passing of the portal circulation would appear to be a -60 --e- potential advantage of the sublingual route for patients 0 2 4 6 8 10 24 with liver disease. Kecent reports in the literature sug- gest an occasional link between the prolonged use of liOUftS oral contraceptives and the development of liver Fig. 1. Relative changes in serum estrogen and gonadotropin tumors.’ Bypassing the liver should be important if concentrations after the sublingual administration of a single such patients were later to need estrogen therapy. half tablet containing 0.5 mg of micronized 17@-estradiol. Clinically, sublingual E2 taken in a dose as small as 0.5 mg every other day brought on marked improvr- 21.6% and LH of 26.0% below baseline. At 36 hours, ment in vaginal atrophy. with complete reversal of the the average increase was still two and one half fold for maturation index to an estrogeni;led pattern. This E,, but EQ, FSH, and LH dropped only slightly on the alternate-day timing was chosen after preliminary clin- average, but not significantly so. ical trials had shown that it was the minimal amount In both groups, vaginal smears for maturation index which still produced an acceptable degree of subjective were carried out at the pretreatment visit and again at relief from symptoms attributable to the menopause.’ the last visit (Table III). The single-dose women expe- Yen and associates,” Martin and associates,’ and Schift rienced marked worsening of their vasomotor symp- and associate? have shown that vaginal E2 accom- toms, and a decrease in the average number of plishes physiologic sustained estrogenization with min- cornihed cells. In the alternate-day women, symptoms imal doses, without a high conversion rate to E,, and attributable to estrogen dehciency subsided or were for many patients this would seem to be the preferable markedly ameliorated. By the twenty-eighth day, then route of administrat.ion. Nevertheless, a substantial vaginal cornihcation had strikingly improved. number of patients objects to the messiness of vaginal creams, or to the daily manipulation necessary for in- Comment sertion of a tablet into the vagina. For them, sublingual The findings of this study demonstrated that mi- micronized E, may well be the alternate method of cronized Ez was rapidly absorbed from the sublingual choice. mucosa in postmenopausal women, resulting in serum The significance of this new information is that a 0.3 EZ levels which rose to a peak within an hour and then mg dose of micronized Ez is absorbed quickly and dropped back rapidly to levels close to baseline. In con- efficiently into the circulation and reaches levels com- trast, as the E2 level dropped, the level of E, gradually parable to those with oral administration of a 2 mg Volume 140 Sublingual absorption of micronized E2 149 Number 2

dose. The conversion of E, to E, after sublingual ad- We would like to thank Mr. Daniel W. Williams for ministration is similar to the conversion after oral ad- the statistical evaluations, Ms. Jill Audad and Mr. ministration, even though the gastrointestinal tract is William Hopper for their excellent technical assistance, bypassed. This differs from vaginal absorption, in and Ms. Cathie Drew for her administrative assistance. which case this major conversion does not take place.

REFERENCES 1. Martin, P. L., Yen, S. S. C., Burnier, A. M., and Hermann, Yen, S. S. C., Martin, P. L., Burnier, A. M., Dzekala, N. M., H.: Systemic absorption and sustained effects of vaginal Greaney, M. 0.. Jr., and Callantine, M. R.: Circulating es- estrogen creams, J.A.M.A. 242:2699, 1979. tradiol, estrone and gonadotropin levels following the ad- 2. Yen. S. S. C.. Llerena. 0.. Little. B.. and Pearson. 0. H.: ministration of orally active 17p-estradiol in postmeno- Disappearance rates of endogenous luteinizing hbrmone pausal women, J. Clin. Endocrinol. Metab. 40:518, 1975. and chorionic gonadotropin in man, J. Clin. Endocrinol. Ryan, K. J.. and Engel, L. L.: The interconversionofestrone Metab. 28: 1763, 1968. and estradiol by human tissue slices, 52:287, 3. Yen, S. S. C., Llerena, L. A., Pearson, 0. H., and Littell, 1953. A. S.: Disappearance rates of endogenous follicle-stimulat- Nissen, E. D., and Kent, D. R.: Liver tumors and oral con- ing hormone in serum following surgical hypophysectomy traceptives, Obstet. Gynecol. 46:460, 1975. in man, J. Clin. Endocrinol. Metab. 30:325, 1970. Schiff, I., Tulchinsky, D., and Ryan, K. J.: Vaginal absorp- 4. DeVane, G. W., Czekala, N. M., Judd, H. L., and Yen, tion of estrone and 17&estradiol, Fertil. Steril. 28:1063, S. S. C.: Circulating gonadotropins, estrogens, and andro- 1977. gens in polycystic ovarian disease, AM. J. OBSTET. GYNECOL. 121:496, 1975.

Discussion postulated that this may occur in the reticuloendothe- DR. GILBERT A. WEBB, San Francisco, California. lial system. It seems unlikely that the blood circulating This paper is a continuation of a series of papers dealing through the liver would be responsible for the conver- with the absorption rates, biologic activity, and the me- sion, since the absorption sublingually and vaginally tabolism of micronized 17p-estradiol (E2) by these same would give the same rate of liver profusion. Thus, a authors, beginning in 1972. It had been shown that Ez very interesting finding awaits further elucidation. was ineffectual when given orally. The fact that the sublingual method of absorption However, the first of the series of studies begun in yields such good clinical results, as demonstrated in the 1972 showed that the micronized preparation allowed relief of postmenopausal symptoms, allows one to uti- effecive absorption and metabolism, and, therefore, re- lize this method of administration of this hormone if it lief of associated menopausal symptoms. is necessary to bypass the liver or portal circulation. Since that time, these authors have demonstrated the The speculation has been that the passage of estrogen absorption, sustained effects, and metabolism of Ez in through the portal circulation with the use of oral the micronized preparation by vaginal administration. contraceptives has possibly contributed to the benign The current paper dealing with the sublingual absorp- liver tumors observed. It would be interesting to see tion of Ez has demonstrated some very interesting phe- whether the sublingual administration of oral con- nomena. As the authors have pointed out from Ryan’s traceptives would minimize or prevent that particular original work, the intestinal mucosa will convert E2 to problem. El, thus giving a high degree of metabolization of the One of the most interesting findings was that the micronized Ez to estrone (E,) when given orally. How- authors demonstrated blood levels of both estrone and ever, they demonstrated in the study on vaginal ab- 17/l-estradiol with the use of a sublingual dose one sorption that this did not occur. It has also been shown quarter of the oral dose. This would certainly seem to that, when drugs are administered rectally, they bypass be a very significant economic advantage, as well as the portal circulation. Therefore, this bypassing of the reducing the total dose of estrogens administered to portal circulation has been postulated to minimize the these patients. The relationship between the use of es- conversion of vaginally administered Ez to El, since the trogens and the initiation of uterine malignancy has same circulation patterns exist. certainly been a subject of considerable discussion. In the current study, it was interesting that the sub- Estrone has been postulated to be the estrogen that lingual administration of Ez gave a very high initial predominantly stimulates carcinogenesis. Therefore, concentration of E$. but that there was conversion by advantages supposedly reside in the use of an Ez prep- an unknown pathway to El in essentially the same pro- aration that is not converted to estrone. The authors portion that was observed with oral administration. It demonstrated that this was not feasible with the sublin- will be very interesting to see whether these authors are gual method, but that it is feasible with the vaginal able to discover how this conversion occurs. They have method. 150 Burnier et al.

These authors are to be congratulated for their COW inf’ormation. A large nuniber of women could benellt tinued interest in a drug which is very usef’ul ill pre- tram these data. 1%‘~ look forward to laboratory and venting menopausal symptoms and effective in estro- clinical studies which will explore tltrther this route of gen replacement therapy. It is hoped that they will estrogen administration. continue their investigation of the means bp lvhich the DR. PURVIS MARTIN, San Diego, (;alifijrllia. 1 \\ould body metabolizes E2 to E,. like to emphasize some of’ the clinical practicalities of DR. LEO LAGASSE, Los Angeles, Calif’ornia. Any this work. .4r the present time in ww ~~~mop;l~~sc clinic. method of’ delivery of estrogenic hormone that would WC LIW micronized estradiol, or Estracc, in two thirds of achieve the desired effect with reduced dosage and noi our patients. It is more physiologic than other clinicall!~ rely upon the liver would seem to be beneficial. Dr. available estrogens. M’e are using as much vaginal Es- Howard Judd, of our endocrinology division, has trace in tablets as orally. We think that the vaginal route stresssed that, it’ one can decrease the’involvement of is much more physiologic. The bottom line is. it’ YOU the liver in hormone metabolism, then some of’ the want to bypass the liver. there are two I\-ays to do it \rittl complications of hormone therapy, such as blood pres- Estracc. Use the 1 mg tablet. which is almost colorless. sure problems. can be avoided. If‘ one can achieve an rather than the 2 mg tablet. which colors clothing blue. equivalent ef’f’ect by taking a smaller dose, then the Give a half milligram sublingually CYTJ-~ other (lay. and risk-to-benefit ratio would swing in t‘avor of’ benefits. ~OLI will achieve a ver!’ good symptomatic result whiclt Reduced incidence of osteoporosis, alleviation of’ hot IS \‘er)- acceptable to the patients. Or !Y,U GUI give halt ;I flashes, and the maturation of’ vaginal mucosa, all arc milligram of Estracc vaginallp ever) other da\ ~JKI important benefits. Certainly, there are risks. The chief produce the physiologic estrogen lc\el o! ;I prr- one is the risk of’ endometrial cancer. Between 19’iO menopausal woman, lvithout conversion to cstrone. \Vc- and 197.5, the incidence of’ endometrial cancer iti- believe that the tnost physiologic !~-a\ of administering creased by W,, in Caucasian women. There was essen- estrogen is vaginally. and this is act-cp~ablc to at least tially no increase in incidence during the preceding 50 5% ot the patients. The next most ph\siologic- route is years. There is no evidence that estrogen-associated sublingually, with a much lowel- effecti\-c dose than tn endometrial tumors are of’ lower grade, demonstrate the least physiologic route, which is orallv. less myometrial invasion, are seen with lower stage, and DR. BURNIER (Closing). In answer tc, Dr. \Veber’s demonstrate a lower death rate. Nevertheless, the large question, the endotnetrium was not tnonitorcd during increase in estrogen-associated cases is apparent. There this stud\-. is some evidence that increases in rhe risk of cancer are \l’ith t’egard to the vaginal maturzatioll index. tllere related to both duration of drug therapy and the dose was JIO improvement. as would be cxpec ted. i monrh administered. The lowest effective dose is the best. The af’ter a single dose of estrogen: whereas patients who suggestion of‘this study that a dose given sublingually is received 0.5 mg of micronized estradiol e\‘rry other more effective than one given by the oral route, and, clay showed marked improvement in their vaginal at- therefore. that a smaller dose can be used, is ~~setul roph\~.