Abstract

APPLICATION OF HPTLC FOR THE ESTIMATION OF LAWSONE, ITS METABOLITES AND INVESTIGATION OF INTERACTION OF LAWSONE WITH CAFFEINE BY INVITRO METHODS

Gandhimathi Muruganathan*, Bharathi Mandala

ABSTRACT

Lawsone is a bio medicament used in the treatment of psoriasis. A HPTLC method was developed and employed for the investigation of its interaction with caffeine. Lawsone and its two metabolites, viz salicylic acid and catechol were estimated from spiked plasma by HPTLC using invitro methods. HPTLC separation comprised of solvent system toluene: ethyl acetate: ethanol: formic acid in the ratio of 8:2:1:1 drop % v/v/v/v detection was done at 254nm. The Rf value of lawsone, salicylic acid and catechol were found to be 0.37, 0.33 and 0.49 respectively. The interaction study was carried out in two temperature 37°C and 45°C, and in gastric pH. A significant interaction was observed in higher concentration of caffeine both conditions. The Rf value of lawsone and caffeine were found to be 0.47 and 0.29 respectively. For interaction study the linearity was established between 20-640 μg/ml for Lawsone and 20-640μg/ml for caffeine. In the spiked plasma linearity was found to be in the concentration range of 80-280 μg/ml for Lawsone, 40-140μg/ml for salicylic acid, 320-1120 μg/ml for Catechol. The invitro estimation of lawsone and metabolites involved single step extraction from plasma and cost effective, and can be employed for pharmacokinetic studies and further research on lawsone.

Keywords: Lawsone, metabolites, plasma, interaction, caffeine, HPTLC.