Elution from intact and broken vaginal contraceptive rings: an in vitro study

Objective The in vitro elution of the active substances etonogestrel and ethinylestradiol of the vaginal ring Ornibel® was determined after active breakage of the ring and compared to the standard elution and hormone release of unbroken rings under the same conditions.

Methods 6 Ornibel® contraceptive rings were broken deliberately and, in parallel with 6 non-broken rings from the same batch, were subjected to a standardized in vitro elution (IVE) procedure for 21 days. Hormone dissolution was determined by HPLC. In a second approach, rings were broken only at day 7 and their elution profiles were compared to that of intact rings. For all utilized batches, the stability conditions established were 24 months at 5 °C.

Results Average elution for non-broken rings was for etonogestrel on day 1: 119 µg/day; for days 2-20: 132 µg/day and for day 21: 111 µg/day. For broken rings average elution was as follows: day 1: 118 µg/day; days 2-20: average: 132 µg/day and for the day 21: average: 111 µg/day. The following average values were obtained for ethinylestradiol: non-broken rings: day 1: average: 15 µg/day; for days 2-20: 18 µg/day and for day 21: 18 µg/day. For the broken rings the following values were obtained on average: day 1: 14 µg/day; days 2-20: 19 µg/day and for day 21: 18 µg/day. Correspondingly, the IVE results from intact rings and their counterparts broken on day 7 did not differ.

Conclusions It can be concluded from this study that broken vaginal rings display the same hormonal release for etonogestrel and ethinyl estradiol as intact ones.

Interessenkonflikt

Anna Müller, Manuela Sailer und Pedro-Antonio Regidor sind Angestellte der Exeltis Germany GmbH. Alle anderen Autoren haben erklärt, dass kein Interessenkonflikt besteht.

Publication History

Article published online:
07 October 2020