Hydrophobicity and antifilarial activities of 4-aminoquinolines

The apparent partition coefficients (Papp.) of eight 4-aminoquinolines in 1-octanol/pH 7.4 buffered solutions have been determined and correlated with their reported antifilarial activities. Antifilarial activity appears to be present only in those 4-aminoquinolines which have log Papp. values falling within a narrow range of 2.8 to 3.2.