Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies

Area of Science:

• Reproductive Health
• Drug Delivery Systems
• Infectious Disease Prevention

Background:

• Intravaginal rings (IVRs) are established for delivering contraceptive steroids and treating vaginal atrophy.
• A novel application is the delivery of antiretroviral drugs (microbicides) for HIV prevention.
• Multipurpose Prevention Technology (MPT) IVRs aim to prevent pregnancy and reproductive tract infections, including HIV.

Purpose of the Study:

• To review microbicide and MPT IVRs currently in development.
• To focus on the clinical aspects of IVR assessment and product development challenges.
• To highlight challenges in clinical testing and implementation of these novel IVRs.

Main Methods:

• Literature review of PubMed searches.
• Inclusion of data from a microbicide/MPT product development workshop.
• Focus on clinical assessment, safety, pharmacokinetics, and pharmacodynamics.

Main Results:

• IVRs offer sustained, controlled drug release, bypassing first-pass metabolism.
• Advantages include discreet, woman-controlled use without a trained provider.
• Several MPT IVRs are in development, requiring rigorous clinical evaluation.

Conclusions:

• Early clinical testing must prioritize safety, efficacy, and minimal disruption to vaginal health.
• Key challenges include achieving active tissue drug concentrations, avoiding mucosal alterations, and preventing antimicrobial resistance.
• Successful implementation requires addressing drug resistance, expulsion rates, and user experience.