SIMULTANEOUS DETERMINATION OF PARABENS IN PHARMACEUTICAL PREPARATIONS USING HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY AND IMAGE ANALYSIS

Abstract

A study for quantitative evaluation of thin layer chromatographic plates by using, for the first time, the BioDit Thin Layer Chromatography (TLC) Scanner device in UV mode was developed for simultaneous determination of the parabens (methyl, ethyl, propyl, and butylparaben) in pharmaceutical preparations. ImageDecipher-TLC software and Sorbfil TLC Videodensitometer were used for image processing analysis. After their chromatographic separation, the quantification of the parabens was made by the conversion of RGB colored images of TLC plates (obtained by UV light scanning at λ = 254 nm) into grey scale. Experimental results showed a strongly linear correlation between area of grey spots and concentration of parabens covering a relatively large domain of concentration in all cases. The linearity of the analytical procedure was in range of 0.46–2.47 µg/spot for methylparaben, 0.50–2.99 µg/spot for ethylparaben, 0.54–3.24 µg/spot for propylparaben, and, respectively, 0.58–3.49 µg/spot for butylparaben, the regression determination coefficient being higher than 0.9977 in all cases. The recovery studies performed on two levels of concentration gave values higher than 96.32% in the case of ImageDecipher-TLC software for all studied parabens. The limits of detection and quantification varied in that case between 0.10–0.37 µg/spot and 0.20–0.44 µg/spot, respectively. The proposed method was found to have a good precision and accuracy and their applicability was assessed for commercial pharmaceutical syrup samples analysis.

Keywords:

• HP-TLC
• image processing
• parabens
• quantitative evaluation
• UV scanning

Notes

* – x: sample concentration; y: peak area.

(I) ImageDecipher-TLC software for image analysis.

(II) Sorbfil TLC Videodensitometer software for image analysis.

(I) – data obtained with ImageDecipher-TLC software.

(II) – data obtained with Sorbfil TLC Videodensitometer software.

*The data refer to the mean obtained for three replicates spots.