Table 2.

Summary of microbicide-releasing vaginal ring devices either previously evaluated or under ongoing investigation

Microbicide(s)	Polymer type	Ring type	References
Dapivirine	Silicone elastomer	Reservoir and matrix	23,24,25
	Polyurethane	Matrix Reservoir	6,7,9
	Biosoluble acacia gum		45
Maraviroc	Silicone elastomer	Matrix	34
CMPD167	Silicone elastomer	Matrix	34
MC1220	Silicone elastomer	Matrix	33
AZT	Biosoluble acacia gum or a hydrogel	Reservoir	44,45
Boc-LBA	Biosoluble acacia gum	Reservoir	45
Tenofovir	Silicone elastomer (carrier) Polyurethane	Pod ring Matrix	38,40
MIV-160	Poly(ethylene-co-vinyl acetate)	Matrix	58
UC781	Silicone elastomer	Matrix	8
	Polyurethane	Matrix	8,37
	Poly(ethylene-co-vinyl acetate)	Matrix	36
Dapivirine + tenofovir	Biosoluble acacia gum or a hydrogel	Reservoir	45
	Polyurethane	Matrix	7
Dapivirine + maraviroc	Silicone elastomer	Matrix	n/a
	Poly(ethylene-co-vinyl acetate)	Matrix	n/a
Tenofovir and acyclovir	Silicone elastomer (carrier)	Pod ring	38
IQP-0528 and tenofovir	Polyurethane	Matrix	n/a
Saquinavir, lopinavir and ritonavir	Silicone elastomer	Matrix	n/a

Abbreviations: n/a, reference not available; MRI, magnetic resonance imaging; PII, Phase II; C, control.