Carrageenan/MIV-150 (PC-815), a Combination Microbicide

Objective: The objective of this article is to study the effect of PC-815, a novel combination microbicide containing carrageenan and the nonnucleoside reverse transcriptase inhibitor (NNRTI) MIV-150, in blocking HIV-1 and HIV-2 infections in vitro as compared with Carraguard alone. Goal: The goal of this study was to develop a combination microbicide that is more efficacious than Carraguard against HIV-1 and HIV-2. Study Design: The microtiter syncytial assay was used to evaluate: 1) the antiviral and virucidal activity of MIV-150 against HIV-1MN; 2) the additive effect of MIV-150 when combined with carrageenan; and 3) a possible interference of seminal fluid in the antiviral activity of these compounds. Results: MIV-150 effectively inactivated free virus. Combination of MIV-150 and Carraguard demonstrated an additive antiviral effect. Seminal fluid had no effect on the antiviral activity of MIV-150 or Carraguard. The average concentration that blocks 50% of infection (EC50) for PC-815 was approximately 10 times stronger than Carraguard for the different clinical isolates used in the study. Conclusion: Theoretically, PC-815 is likely to be a more efficacious microbicide than Carraguard.