Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Evaluation of Dimethylformamide (DMF) as an Organic Modifier in Hydrophobicity Index (Rm) Determination

Olakunle S Idowu , Adedigbo A Fasanmade, Ajibola A Olaniyi

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Nigeria;

For correspondence:- Olakunle Idowu Email: olakunleid@yahoo.com Tel:+ 234 802 309 4981

Published: 23 December 2002

Citation: Idowu OS, Fasanmade AA, Olaniyi AA. Evaluation of Dimethylformamide (DMF) as an Organic Modifier in Hydrophobicity Index (Rm) Determination. Trop J Pharm Res 2002; 1(2):83-89 doi: 10.4314/tjpr.v1i2.5

© 2002 The authors.
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Abstract

Purpose: Ideal behaviour of mixtures of organic modifier and water is reflected by a linear relationship between refractive index and fraction of organic modifier in the mixture. This study was carried out to investigate dimethylformamide (DMF) as an organic modifier in hydrophobicity index (Rm ) determination.
Method: We quantitatively evaluated the problem of partial miscibility of phases associated with the reversed phase thin layer chromatographic (RPTLC) system, using liquid paraffin as stationary phase and acetone/water mixtures as mobile phase. Ideality of behaviour of acetone /water mixtures was investigated by refractive index measurements. Rm values of compounds were determined using mixtures of acetone and water as mobile phase.
Results: DMF/water mixture behaved ideally across the whole concentration range investigated (0-100%) while acetone/water mixture deviated from ideal behaviour when the concentration of acetone in the mixture was 80%. DMF also gave a better extrapolation of Rm value from linear regression of partition data than acetone for bezafibrate used as a test-drug molecule.
Conclusion: DMF is a better organic modifier than acetone in this RPTLC system. These findings could be extended to drug-receptor and drug design studies. The use of dimethylformamide (DMF) in preference to acetone as organic modifier is proposed in this study.

Keywords: Drug design, dimethylformamide, hydrophobicity index, organic modifiers