Formulation of quinine suppository for initiation of early treatment of malaria - a preliminary study.

Background: In the management of malaria, there is the need for early initiation of treatment. An antimalarial drug for home use must be easy to administer, safe, effective and affordable. Parenteral quinine is the gold standard for treatment of severe malaria. A rectal formulation of quinine will therefore serve the purpose of early initiation of care in patients that lack easy access to medical centers. The main objective of this preliminary work was to develop a quinine suppository with adequate release properties that also meets the dual conditions of affordability and ease of administration. Materials and Methods: Cocoa butter and Fattibase™ were used in the preparation of suppositories containing 200 mg quinine bisulphate. The release profiles of formulations with varying concentrations of polysorbate 80 (0 - 5%) were evaluated by in vitro dissolution in pH 8 buffer medium. Results: The addition of polysorbate 80 improved the release of quinine significantly at 2 and 5%. Cocoa butter suppository with 1% polysorbate 80 released 73.6 mg quinine bisulphate in 1 hr while release from suppositories with 2% and 5% surfactant was higher. Fattibase™ suppositories had better release profiles than cocoa butter formulations. The formulation with 5% polysorbate 80 released 170 mg quinine in 1 hr. Formulations with the two bases released quinine in adequate quantities for the management of malaria. Conclusions: The particle size of quinine is an important factor affecting the physical appearance and drug release from the suppository. The Fattibase™ suppositories were more stable but cost five times the price of the cocoa butter formulations. The cocoa butter formulations, however, still released quinine in sufficient quantities for the management of malaria. Cocoa butter formulations will be more affordable in resource-limited malaria-endemic regions of the world.