Malaria is the most common parasitic disease around the world, especially in 
tropical and sub-tropical regions. This parasitic disease can have a rapid and 
severe evolution. It is transmitted by female anopheline mosquitoes. There is no 
reliable vaccine or diagnostic test against malaria; instead, Artesunate is used 
for the treatment of severe malaria and Artemisinin is used for uncomplicated 
falciparum malaria. However, these treatments are not efficient against severe 
malaria and improvements are needed. Primaquine (PQ) is one of the most widely 
used antimalarial drugs. It is the only available drug to date for combating the 
relapsing form of malaria. Nevertheless, it has severe side effects. Particle 
drug-delivery systems present the ability to enhance the therapeutic properties 
of drugs and decrease their side effects. Here, we report the development of 
Polymeric Primaquine Microparticles (PPM) labeled with 99mTc for therapeutic 
strategy against malaria infection. The amount of primaquine encapsulated into 
the PPM was 79.54%. PPM presented a mean size of 929.47 ± 37.72 nm, with a PDI 
of 0.228 ± 0.05 showing a homogeneous size for the microparticles and a 
monodispersive behavior. Furthermore, the biodistribution test showed that 
primaquine microparticles have a high liver accumulation. In vivo experiments 
using mice show that the PPM treatments resulted in partial efficacy and 
protection against the development of the parasite compared to free Primaquine. 
These results suggest that microparticles drug delivery systems of primaquine 
could be a possible approach for malaria prevention and treatment.