Calculation procedures and HPLC method for analysis of the lipophilicity of acyclovir esters

Acyclovir (ACV) belongs to a class of drugs with low bioavailability. Selected ACV esters including acetyl (Ac-), isobutyryl (iBut-), pivaloyl (Piv-), ethoxycarbonyl (Etc-) and nicotinoyl (Nic-) were synthesized, and their lipophilicity was determined by the high-performance liquid chromatography (HPLC) RP method. Statistical analyses of the comparative values of log P and clog P were carried out using computational methods. It was proved that the AC log P algorithm can be useful for the analysis of these compounds and has a statistically justified application in the assessment of the quantitative structure-activity relationship. Moreover, the lipophilicity determined by the HPLC method appears as follows: ACV < Ac- < Nic- < Etc- < iBut- < Piv-.