Lipophilicity Investigations of Ibuprofen

Abstract

Ibuprofen was investigated with the use of reversed phase thin layer chromatography on RP2F₂₅₄, RP8F_254s, and RP18F_254s (E. Merck), using methanol-water in different volume compositions as a mobile phase. The chromatographic parameters of lipophilicity (R_MW(RP2), R_MW(RP8), and R_MW(RP18)) of the studied ibuprofen were determined. The experimental n-octanol-water partition coefficient (logP_exp) by means of the so called shake flash method was determined for ibuprofen. Lipophilic parameters (R_MW(RP2), R_MW(RP8), and R_MW(RP18)) were compared, both with measured (logP_exp) and calculated partition coefficients (AlogPs, AClogP, AB/logP, COSMOFrag logP, miLogP, AlogP, mlogP, logP_Kowwin, xlogP2, xlogP3, and logP_Rekker). Comparing all calculation procedures, generally logP_Kowwin and logP_Rekker are more appropriate for the chromatographic parameter of lipophilicity R_MW(RP18) and experimental n-octanol-water partition coefficient of the studied ibuprofen. The results indicate that the chromatographic parameter of lipophilicity determined on a RP18F_254s plate may be used as a measure of lipophilicity of the investigated ibuprofen.

Keywords:

• Densitometry
• Experimental n-octanol-water partition coefficient
• Ibuprofen
• Lipophilicity parameter R_MW
• RP-TLC
• Theoretical partition coefficient

ACKNOWLEDGMENT

This research was financed by the Ministry of Science and Information Society Technologies by resources reserved for science in the years 2005–2008 as research project No. 3 T09A 155 29.