Dual segment polyurethane intravaginal rings (IVRs) were fabricated to enable 
sustained release of antiretroviral agents dapivirine and tenofovir to prevent 
the male to female sexual transmission of the human immunodeficiency virus. Due 
to the contrasting hydrophilicity of the two drugs, dapivirine and tenofovir 
were separately formulated into polymers with matching hydrophilicity via 
solvent casting and hot melt extrusion. The resultant drug loaded rods were then 
joined together to form dual segment IVRs. Compression testing of the IVRs 
revealed that they are mechanically comparable to the widely accepted NuvaRing 
IVR. Physical characterization of the individual IVR segments using wide angle 
X-ray scattering and differential scanning calorimetry determined that 
dapivirine and tenofovir are amorphous and crystalline within their polymeric 
segments, respectively. In vitro release of tenofovir from the dual segment IVR 
was sustained over 30 days while dapivirine exhibited linear release over the 
time period. A 90 day accelerated stability study confirmed that dapivirine and 
tenofovir are stable in the IVR formulation. Altogether, these results suggest 
that multisegment polyurethane IVRs are an attractive formulation for the 
sustained vaginal delivery of drugs with contrasting hydrophilicity such as 
dapivirine and tenofovir.