[New antimalarial sustained-release formulations based on bioresorbable polymers: therapeutic evaluation using the...

Chemotherapy keeps an important place in malaria control programme. The development of schizonticidal formulations, which may maintain their efficacy for at least one month after single administration, becomes needful. These formulations should allow to assure a suitable patient compliance and to avoid the disadvantages of high plasmatic peaks. The aim of this study is to evaluate the therapeutic efficacy of implantable bioresorbable reservoir-forms. The use of these polymers allow to avoid the surgical extraction of implanted preparations. Two drug delivery systems were prepared: microspheres and rods. Pyrimethamine, as a drug model was incorporated. Therapeutic activity of these preparations was evaluated on a TB mice-Plasmodium berghei model. Polycaprolactone and polylactide 100 microspheres are not suitable for long-term treatment. In contrast, implantable subdermic rods allowed to fulfil the long-term coverage requirements. Their activity depend on the administered dose and the drug content in implants. Polycaprolactone, polylactide 100 and polylactide 50 implants containing respectively 21.5%, 19-40% of pyrimethamine have protected animals for at least three months.