Formulation of anti-malaria capsules based on the fruit of Picralima nitida (Stapf) T. Durand and H. Durand (Apocynaceae

Abstract

Malaria is a parasitic disease that is widely spread throughout the world. The annual number of cases is estimated at around 500 million; the African continent is the most affected, accounting for 95% of cases. For the treatment, WHO recommends artemisinin-based combinations; unfortunately, the cost of these combinations is relatively high, making them difficult to afford. This justifies the search for new antimalarial drugs. A large number of plant species in Cameroon have been identified as anti-malarial medicinal plants. Picralima nitida is one of the plants traditionally used to treat malaria in traditional medicine, and its in vitro and in vivo antimalarial activity and toxicological profile have already been scientifically demonstrated. The aim of the present study was to formulate capsules based on the aqueous extract of Picralima nitida fruit, in an attempt to rationalize its use in the treatment of malaria. The aqueous extract of Picralima nitida fruit was prepared by maceration and then stabilized; its physicochemical characteristics were determined. The daily quantity of extract required for the treatment of malaria was determined in milligrams of total alkaloids. Finally, the extract was stabilized before being filled into capsules using European pharmacopoeia techniques. The capsules were also tested according to European Pharmacopoeia 11th edition techniques. The extract was obtained in 6.25% yield. The extract was soft, hygroscopic, brown in color, very bitter in flavor and caramel in odor. The following phytochemical groups were present in the extract: alkaloids, phenolic compounds, flavonoid tannins, anthocyanins, saponins, terpenes, sterols. Total alkaloid content was 0.11g per gram of extract. To stabilize the extract and make it suitable for capsule filling, 25% colloidal silica and 13% microcrystalline cellulose were added. The stabilized extract showed good flowability (flow time 6s, Carr index 11.8% and Hausner index 1.13), a moderately fine powder texture (d50 < 300um) and homogeneous distribution. The daily dose determined for a 60 kg adult was 3900mg of extract, corresponding to 313 mg of total alkaloids, which could be divided into 8 N°0 or 12 N°00 capsules. On inspection, the capsules were found to comply with the requirements of the 11th edition of the European Pharmacopoeia. The characteristics of the formulated capsules are favorable to make them a good candidate for the various phases of clinical trials with a view to making them an improved traditional medicine (ITM)