CORRELATION BETWEEN ANGIOTENSIN-CONVERTING ENZYME INHIBITORS LIPOPHILICITY AND PROTEIN BINDING DATA

Angiotensin-converting enzyme (ACE) inhibitors represent a significant group of drugs primarily used in the treatment of hypertension and congestive heart failure. In this research, seven ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril) were studied to evaluate the relationship between their protein binding and calculated (logP values) or ultra-high performance liquid chromatographytandem mass spectrometry (UHPLC-MS) and reversed-phase thin-layer chromatography (RP-TLC) lipophilicity data ( 0, CHI or C0 parameters, respectively). Their protein binding data varied from negligible (lisinopril) to 99% (fosinopril), while calculated logPKOWWINvalues ranged from -0.94 (lisinopril) to 6.61 (fosinopril). The good correlations were established between protein binding values and logPKOWWIN data (R2=0.7520) as well as between protein binding and chromatographic hydrophobicity data, 0, CHI or C0parameters (R2 were 0.6160, 0.6242 and 0.6547, respectively). The possible application of hydrophobicity data in drugs protein binding evaluation can be of great importance in drug bioavailability.