RPLC gains acceptance in pharmaceutical research for the rapid determination of lipophilicity but remains limited for the determination of partition coefficients of moderate to strong basic compounds under their neutral form because stationary phases are not compatible with high pH conditions. In this work, HILIC technique was used to accurately measure log P(oct) of the neutral form of basic drugs by measuring the difference between 2 isocratic log k values (Delta log k(0-95)) of their cationic form.