title: Synergistic activity of tenofovir and nevirapine combinations released from polycaprolactone matrices for potential enhanced prevention of HIV infection through the vaginal route.
abstract: Polycaprolactone (PCL) matrices were simultaneously loaded with the antiviral agents, tenofovir (TFV) and nevirapine (NVP), in combination to provide synergistic activity in the prevention of HIV transmission through the vaginal route. TFV and NVP were incorporated in PCL matrices at theoretical loadings of 10%TFV-10% NVP, 5%TFV-5%NVP and 5%TFV-10%NVP, measured with respect to the PCL content of the matrices. Actual TFV loadings ranged from 2.1% to 4.2% equating to loading efficiencies of about 41-42%. The actual loadings of NVP were around half those of TFV (1.2-1.9%), resulting in loading efficiencies ranging from 17.2% to 23.5%. Approximately 80% of the initial content of TFV was released from the PCL matrices into simulated vaginal fluid (SVF) over a period of 30 days, which was almost double the cumulative release of NVP (40-45%). The release kinetics of both antivirals over 30 days were found to be described most satisfactorily by the Higuchi model. In vitro assay of release media containing combinations of TFV and NVP released from PCL matrices confirmed a potential synergistic/additive effect of the released antivirals on HIV-1 infection of HeLa cells. These findings indicate that PCL matrices loaded with combinations of TFV and NVP provide an effective strategy for the sustained vaginal delivery of antivirals with synergistic/additive activity.
authors.affiliation: The University of Queensland, School of Pharmacy, St Lucia, Australia.
authors.forename: Nhung T T
authors.initials: NT
authors.lastname: Dang
authors.affiliation: Queensland Institute of Medical Research, Molecular Virology Laboratory, Brisbane, Australia.
authors.forename: Haran
authors.initials: H
authors.lastname: Sivakumaran
authors.affiliation: Queensland Institute of Medical Research, Molecular Virology Laboratory, Brisbane, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Harrich
authors.affiliation: The University of Queensland, School of Pharmacy, St Lucia, Australia.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Shaw
authors.affiliation: The University of Queensland, Clinical Medical Virology Centre and Royal Children's Hospital, Sir Albert Sakzewski Virus Research Centre, Brisbane, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Davis-Poynter
authors.affiliation: The University of Queensland, School of Pharmacy, St Lucia, Australia. Electronic address: AllanCoombes@imu.edu.my.
authors.forename: Allan G A
authors.initials: AG
authors.lastname: Coombes
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000737:chemistry; D004333:Drug Administration Routes; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D019829:Nevirapine / Q000008:administration & dosage* / Q000737:chemistry; D063065:Organophosphonates / Q000008:administration & dosage* / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D000068698:Tenofovir; D014621:Vagina
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D011091:Polyesters; C016240:polycaprolactone; D019829:Nevirapine; D000068698:Tenofovir; D000225:Adenine
keywords: Anti-HIV drugs; Drug combination; Microbicides; Nevirapine; Polycaprolactone matrices; Synergistic activity; Tenofovir; Vaginal drug delivery