Progesterone release from a silicone intravaginal ring in pigtailed macaques

Sara E. Butler, Priya Srinivasan, Deborah Lowry, Susan Fetherston, James Smith, Karl Malcolm, Jaime Moscoso

Research output: Contribution to journalConference abstractpeer-review

Abstract

Background: Heterosexual HIV transmission continues to spread worldwide. Intravaginal rings (IVRs) formulated with antiretroviral drugs hold great promise for HIV prevention in women. IVRs provide the benefit of being coitally-independent and coitally-covert for an extended period. As a proof-of-concept, we tested the in vivo release of progesterone from a silicone elastomer vaginal ring device. Methods: Six female pig-tailed macaques were treated with a GnRH agonist (Lupron) prior to ring placement. Four macaques received a progesterone-loaded silicone ring, and two macaques received a blank silicone ring. Blood, vaginal swabs, CVL, and/or biopsies were collected during ring placement, and after ring removal. Results: The median plasma progesterone levels for macaques with a progesterone IVR were 13,973 pg/ml (day 3), 12,342 pg/ml (day 7), 10,112 pg/ml (day 14), 8445 pg/ml (day 21) and 8061 pg/ml (day 28), with a significant decrease from day 14 to day 21 (P = 0.0286). The median plasma progesterone levels for macaques with a blank IVR were 221±±± ±±88 pg/ml. Macaques with a progesterone IVR had CVL progesterone levels of 20,935 pg/ml (day 7), 6892 pg/ml (day 21) and 11,515 pg/ml (day 28). Macaques with a blank IVR had CVL progesterone levels of 29 �± 13 pg/ml. There were no disturbances to the normal vaginal microflora, and plasma and CVL cytokine analysis did not indicate a proinflammatory response due to ring placement. The vaginal biopsies did not display any pathology following ring removal. Overall, the IVRs were well tolerated without any indication of inflammation or significant changes in the vaginal compartment.
Original languageEnglish
Article number64
Pages (from-to)267
Number of pages1
JournalJournal of Medical Primatology
Volume40
Issue number4
Early online date22 Jul 2011
DOIs
Publication statusPublished - Aug 2011
Event8th Annual Symposium on Nonhuman Primate Models for AIDS - New Orleans, LA, United States
Duration: 19 Oct 201022 Oct 2010

Bibliographical note

28th Annual Symposium on Nonhuman Primate Models for AIDS, 19-22 October 2010, New Orleans, LA (US)

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