In 2018, Veranova carried out stability and compatibility studies for the development of an anti-retroviral and contraceptive vaginal ring.
Due to the target region and the limited availability of medical supplies and refrigerated storage conditions in this particular area, the stability of both APIs was critical at elevated temperatures. Longevity and stability of release rate from the polymer blends was also key to ensure that dosing/use could be prolonged over a 3 month period.
Previous data had been collected on both dapivirine and darunavir, but not in combination with one another, so interaction of both APIs with the polymer matrices was also of interest.
Scope of work carried out at Veranova:
- HPLC method compatibility for analysis of both APIs simultaneously
- Assay and % recovery
- Purity profiling
- Dissolution to confirm stable release rate over time
- Storage of the supplied polymer discs at 3 different conditions
- XRPD and DSC method development for analysis of the discs at each time point
The study showed that both APIs remained stable over the 3 month period investigated, but some loss in purity of the darunavir API was observed during sample preparation, when heat was applied to melt the polymer blends. A recommendation was made for a particular blend of polymer (silica based) that showed little or no variation even at extreme temperatures (70 °C).