title: Safe and sustained vaginal delivery of pyrimidinedione HIV-1 inhibitors from polyurethane intravaginal rings.
abstract: The potent antiretroviral pyrimidinediones IQP-0528 (PYD1) and IQP-0532 (PYD2) were formulated in polyurethane intravaginal rings (IVRs) as prophylactic drug delivery systems to prevent the sexual transmission of HIV-1. To aid in the selection of a pyrimidinedione candidate and the optimal loading of the drug in the IVR delivery system, four pyrimidinedione IVR formulations (PYD1 at 0.5 wt% [PYD1(0.5 wt%)], PYD1(1 wt%), PYD2(4 wt%), and PYD2(14 wt%)) were evaluated in pigtail macaques over 28 days for safety and pyrimidinedione vaginal biodistribution. Kinetic analysis of vaginal proinflammatory cytokines, native microflora, and drug levels suggested that all formulations were safe, but only the high-loaded PYD2(14 wt%) IVR demonstrated consistently high pyrimidinedione vaginal fluid and tissue levels over the 28-day study. This formulation delivered drug in excess of 10 μg/ml to vaginal fluid and 1 μg/g to vaginal tissue, a level over 1,000 times the in vitro 50% effective concentration. The in vitro release of PYD1 and PYD2 under nonsink conditions correlated well with in vivo release, both in amount and in kinetic profile, and therefore may serve as a more biologically relevant means of evaluating release in vitro than typically employed sink conditions. Lastly, the pyrimidinediones in the IVR formulation were chemically stable after 90 days of storage at elevated temperature, and the potent nanomolar-level antiviral activity of both molecules was retained after in vitro release. Altogether, these results point to the successful IVR formulation and vaginal biodistribution of the pyrimidinediones and demonstrate the usefulness of the pigtail macaque model in evaluating and screening antiretroviral IVR formulations prior to preclinical and clinical evaluation.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Todd J
authors.initials: TJ
authors.lastname: Johnson
authors.forename: Priya
authors.initials: P
authors.lastname: Srinivasan
authors.forename: Theodore H
authors.initials: TH
authors.lastname: Albright
authors.forename: Karen
authors.initials: K
authors.lastname: Watson-Buckheit
authors.forename: Lorna
authors.initials: L
authors.lastname: Rabe
authors.forename: Amy
authors.initials: A
authors.lastname: Martin
authors.forename: Chou-Pong
authors.initials: CP
authors.lastname: Pau
authors.forename: R Michael
authors.initials: RM
authors.lastname: Hendry
authors.forename: Ron
authors.initials: R
authors.lastname: Otten
authors.forename: Janet
authors.initials: J
authors.lastname: McNicholl
authors.forename: Robert
authors.initials: R
authors.lastname: Buckheit
authors.forename: James
authors.initials: J
authors.lastname: Smith
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Kiser
mesh_terms: D000282:Administration, Intravaginal; D000818:Animals; D019380:Anti-HIV Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002460:Cell Line; D003274:Contraceptive Devices, Female; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D004355:Drug Stability; D005260:Female; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D020128:Inhibitory Concentration 50; D008254:Macaca nemestrina; D011140:Polyurethanes; D011744:Pyrimidinones / Q000493:pharmacokinetics* / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000821:virology; D014018:Tissue Distribution; D014621:Vagina / Q000187:drug effects* / Q000276:immunology / Q000821:virology; D014779:Virus Replication / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D016207:Cytokines; D011140:Polyurethanes; D011744:Pyrimidinones