Estimation of trans-resveratrol in herbal extracts and dosage forms by high-performance thin-layer chromatography.

A simple, sensitive and precise high-performance thin-layer chromatographic (HPTLC) method of analysis of trans-resveratrol in Polygonum cuspidatum root extracts and in dosage forms was developed and validated. The separation was carried out on a TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase, eluted with chloroform-ethylacetate-formic acid (2.5 : 1 : 0.1) as mobile phase. Densitometric analysis of trans-resveratrol was carried out in the absorbance mode at 313 nm. This system was found to give compact spot for trans-resveratrol (Rf value of 0.40+/-0.03). A good linear regression relationship between peak areas and the concentrations was obtained over the range of 0.5-3.0 microg/spot with correlation coefficient 0.9989. The limit of detection and quantification was found to be 9 and 27 ng/spot. The method was validated for precision and recovery. The spike recoveries were within 99.85 to 100.70%. The RSD values of the precision in the range 0.37-1.84%. The proposed developed HPTLC method can be applied for identification and quantitative determination of trans-resveratrol in herbal extracts and dosage forms.