RESUMEN
OBJECTIVES: To assess pharmacodynamic and pharmacokinetic outcomes of a novel copper (Cu) intrauterine system (IUS) releasing ulipristal acetate (UPA) in healthy women. STUDY DESIGN: In this single-blinded, randomized proof-of-concept study, ovulatory women received one of three Cu-IUSs releasing low-dose UPA (5, 20 or 40 µg/d) for 12 weeks. The study included a baseline cycle, three 4-week treatment-cycles and 2 recovery cycles. Primary outcomes included effects of the IUS on bleeding profile, ovarian function, and the occurrence of progesterone receptor modulator associated endometrial changes (PAEC). Pharmacokinetics and safety profile were secondary outcomes. We compared outcomes in treatment-cycle 3 with baseline, using generalized linear mixed models with orthogonal contrasts. RESULTS: We randomized 29 women (5 µg/d = 10, 20 µg/d = 10, 40 µg/d = 9). All had a successful IUS insertion; 27 completed the 12-week treatment period. Compared to baseline, the mean number of bleeding-only days at treatment-cycle 3 declined by 16.7% in the 5 µg/d group (3.6 vs 3.0, p = 0.66), 40.5% in the 20 µg/d group (4.2 vs 2.5, p = 0.14), and 77% in the 40 µg/d group (3.9 vs 0.9, p = 0.002). Most women reported reduction in the amount of bleeding: 4/8, 8/10, and 7/9 for the 5 µg/d, 20 µg/d, and 40 µg/d groups, respectively. During IUS use, ovulation occurred in most cycles [5 µg/d: 23/24 (96%), 20 µg/d: 26/30 (87%), 40 µg/d: 22/27 (81%)]. The frequency of PAEC at IUS removal was 1/10 (10%), 1/10 (10%) and 4/9 (44%) in the 5 µg/d, 20 µg/d, and 4 0 µg/d groups, respectively. No serious adverse events occurred. CONCLUSIONS: Reduction in bleeding, low incidence of PAEC, and no serious adverse events are reassuring findings of the novel Cu-UPA-IUS. The 20 µg/d seems the lowest dose promoting a favorable bleeding profile and limiting PAEC. IMPLICATIONS: The preliminary results of this short-term study of a novel copper intrauterine system (IUS) delivering ulipristal acetate showed reduction of bleeding, low incidence of progesterone receptor modulator associated endometrial changes, and absence of serious adverse events. By preventing copper-induced increase in bleeding, this IUS could provide a noncontraceptive benefit, especially for women with low hemoglobin.
Asunto(s)
Anticonceptivos Femeninos , Dispositivos Intrauterinos Medicados , Norpregnadienos , Femenino , Humanos , LevonorgestrelRESUMEN
Steroid molecules have a long history of incorporation into silicone elastomer materials for controlled release drug delivery applications. Previously, based on in vitro release testing and drug content analysis, we demonstrated indirectly that the contraceptive progestin levonorgestrel (LNG) chemically and irreversibly binds to addition cure silicone elastomers, presumably via a hydrosilylation reaction between the levonorgestrel ethynyl group and the hydrosilane groups in the poly(dimethylsiloxane-co-methylhydrosiloxane) crosslinker of the silicone elastomer. Here, for the first time, we report that solid state 13C nuclear magnetic resonance (NMR) spectroscopy provides direct evidence for the irreversible binding of ethinyl estradiol (EE) - an estrogenic steroid molecule also containing an ethynyl functional group - to an addition cure silicone elastomer. By preparing silicone elastomer samples containing 13C-labelled EE, signals in the NMR spectra could readily be assigned to both the free and bound EE. Additional depolymerisation studies, performed on an addition cure silicone elastomer system from which the unbound EE fraction was completely extracted, further confirmed the presence of bound EE through the formation of coloured reaction mixtures resulting from the reaction of bound EE and trifluoroacetic acid (TFA). These methods will be particularly useful in the ongoing development of new steroid-releasing silicone drug delivery devices, including various vaginal ring devices for contraception, HIV prevention and multipurpose prevention technology applications.