HPTLC determination of gallic acid and tannin in extracts of bearberry leaves

A quantitative high-performance thin-layer chromatographic (HPTLC) method for analysis of gallic acid and tannin in extracts of Arctostaphylos uva-ursi (L.) Sprengel, bearberry leaves (Ericaceae), and validation of the method, are described. Analyses were performed on cellulose F,, HPTLC plates with isobutanol-acetic acid-water, 14 + 1 + 3.5 (v/v), as mobile phase. The chromatographic system afforded satisfactory R(F) (0.35 for gallotannin and 0.46 for gallic acid), low RSD (0.14.44%), and effective resolution between components (R(s) = 1.89). The uva-ursi leaves examined contained approximately 14% tannin and 5% gallic acid. Special features of the thin-layer chromatographic (TLC) technique were taken into consideration in the validation process and calculation of validation data for the method. This HPTLC method was found to be simple, reliable, and convenient for routine analysis. Its analytical performance fulfilled acceptance criteria established for TLC methods in the official literature.