Effect of membrane filtration of antimalarial drug solutions on in vitro activity against Plasmodium falciparum

Authors

J. Kevin Baird, Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, DCFollow
C. Lambros, Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, DC

Date of this Version

1984

Citation

Bulletin of the World Health Organization, 62 (3): 439-444 (1984)

Comments

U.S. Government Work

Abstract

Antimalarial activities ofchloroquine, mefloquine, amodiaquine, and quinine in vitro against Plasmodium falciparum were diminished as a consequence ofmembranefiltration. Filtered drug solutions gave ID₅₀ values up to 25-fold greater than those of non-filtered (ethanol-sterilized) drug solutions. Loss ofactivity byfiltration was overcome by increasing the drug concentration prior to filtration. Water solutions filtered through Millex-GSfilter units consistently showed an absorbance maximum at 277 nm, accompanied by a lesser peak at 225 nm. Water filtrates from Nucleopore and Millex-G Vfilters showed no absorbance at 277 nm and only slight absorbance was evidentfor the Gelmanfilter unit. Activity losses were attributed to extractable contaminating moieties in the membranefilters and/or drug binding to the membrane filters.