Researchers at SRI International say a bioadhesive-based platform delivery could help slow the spread of HIV and HSV in Africa.
The organisation – a non-profit institute that conducts research for government and industry – made the comments after receiving a National Institute of Allergy and Infectious Diseases (NIAID) grant to fund development of the new delivery technology.
The idea is to create a bioadhesive sustained-release formulation that can deliver the antiretroviral tenofovir - used to treat HIV - and the antiviral acyclovir - used to treat HSV - directly to the vaginal surface, which is something that has been attempted before without success according to the grant abstract.
“Several microbicides have failed clinical trials because of lack of efficacy, possibly from limited residence time on the vaginal surface…bioadhesives, which are classified as biocompatible polymers, may lengthen vaginal microbicide residence time, thus minimizing the need for frequent dosing, and their polymer scaffold can also help solubilize drugs.”
SRI will use its patented SR-2P formulation, which contains two pH and temperature-responsive polymers that - when mixed and applied - form an adhesive gel that attaches to the mucosa, creating a platform for drug release.
Gita Shankar, director of formulations R&D at SRI Biosciences, said: "The inexpensive and easy-to-use combination therapy in development could help contain the spread of HIV and HSV, and possibly other sexually transmitted diseases."
"One of the strongest benefits of a topical gel formula is that it can offer protection when options such as condoms are unavailable or unacceptable."
The project will run for an initial period of two years with an option to extend until 2017.
The grant follows just weeks after the US Department of Defense awarded SRI’s bioscience division a one year grant to fund the development of an orally deliverable multiple sclerosis (MS) treatment.
If developed successfully the drug would be a potential rival for the only approved oral MS treatment - Novartis’ Gilenya – which is currently the subject of some safety concerns.