Lipofilnost lijekova. III. dio : Fragmentarni sustav Hanscha i Leoa

Lipophilicity is a property of molecular structure which is essential in predicting the transport and activity of drugs, pesticides and various xenobiotics. The most important parameter which describes lipophilicity in a numerical way is partition coefficient P. It describes the manner in which a bioactive solute partitions between polar and nonpolar phases. For that reason, beside experimental methods for it's determination, there are developed numerical approaches for it's calculation. The most common methods are: by substituting groups for hydrogen (II system) and by summing the appropriate structural elements (fragment systems). In log P calculations today more often are in use computer programs based on this methods. Log P is a widely used parameter in QSAR for quantitative description of lipophilic character of biologically active compounds. Molecular modeling in pharmacy and chemistry is used to rationalize drug design process in order to predict properties and activity, and to reduce the number of compounds to be synthesized.