Microbicides for the Treatment of Sexually Transmitted HIV Infections

Table 7

Outlook behind the disappointing microbicide strategy.

Prerequisite of microbicide candidates	Probable mechanism	Reason for the failure
Candidates who require coating the vaginal epithelial lining uniformly.	Barrier for invasion and disruption of virus	Inability of the delivery system to provide an effective and durable microbicide fence along the epithelial lining.
Candidates who require retaining at the site to achieve appropriate concentration levels either in local tissues or blood.	Reverse transcriptase inhibitor, integrase inhibitor, and protease inhibitor	Insufficiency of delivery systems to provide sustained and controlled microbicide release.
Candidates who require targeting to a particular site	Entry inhibitors (targeting viral and host cell receptors).	Inability of delivery process to target active molecule to required site.