Long-acting formulations can administer medicines through patches or injections that are effective for months, freeing people from daily regimens of pills and making it easier for them to succeed in their treatment.
They take pressure off health systems, combating antimicrobial resistance and halting the spread of diseases.
Unitaid is funding work on solutions for malaria, tuberculosis, HIV and hepatitis C in low-income countries.
The first project seeks to develop a long-acting injectable form of ivermectin, a drug that can interrupt malaria transmission, making it easier to administer and adhere to.
A second project will develop long-acting versions of medicines to cure hepatitis C and to prevent malaria and latent TB, with a view to filing for regulatory approval.
Unitaid is also supporting another project to develop long-acting injections to treat HIV. Simplifying antiretroviral treatment could help people stay on medication, which keeps the virus suppressed and prevents its spread.