title: Dependence of the kinetic and thermodynamic parameters on hydrophilic-lipophilic character of alprazolam, clonazepam, diazepam, doxepin and haloperidol in alkaline environment.
abstract: Examination of the stability of clonazepam, diazepam, alprazolam, haloperidol, and doxepin in basic solutions was performed, together with an assessment of the kinetic (k, t0.1i t0.5) and thermodynamic (Ea, ΔH(++)i ΔS(++)) stability-indicating parameters, which were compared with the lipophilicity (logP) of the studied drugs. It was observed that the calculated values of Ea, ΔH(++) and ΔS(++) for the studied drugs increased from 41.04 kJ/mol to 125.50 kJ/mol, from 37.82 kJ/mol to 122.24 kJ/mol and from -167.09 J/Kmol to 53.02 J/Kmol, respectively, along with an increase of lipophilicity (logP) from 2.12 to 4.30 for the most hydrophilic alprazolam to the most lipophilic haloperidol. The degradation products were identified using UPLC/MS/MS method.
authors.affiliation: Department of Inorganic and Analytical Chemistry, Jagiellonian University, Collegium Medicum, 9 Medyczna Street, 30-688 Cracow, Poland. amasl@cm-uj.krakow.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Maślanka
authors.forename: Jan
authors.initials: J
authors.lastname: Krzek
authors.forename: Marek
authors.initials: M
authors.lastname: Szlósarczyk
authors.forename: Paweł
authors.initials: P
authors.lastname: Żmudzki
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wach
mesh_terms: D000525:Alprazolam / Q000737:chemistry*; D002998:Clonazepam / Q000737:chemistry*; D003975:Diazepam / Q000737:chemistry*; D004316:Doxepin / Q000737:chemistry*; D004355:Drug Stability; D006220:Haloperidol / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D013816:Thermodynamics
chemical_list: D004316:Doxepin; D002998:Clonazepam; D006220:Haloperidol; D003975:Diazepam; D000525:Alprazolam
keywords: LC/MS; Lipophilicity; Stability studies; TLC