gallic acid

Euphorbia Hirta belonging to the Euphorbiaceae family contains more amounts of phenolic compounds and flavonoids which are responsible for the main pharmacological actions like anti-oxidant, anti-inflammatory, anti-dengue and anti-cancer. Considering the current importance of these ingredients, an attempt has been made for the simultaneous estimation of gallic acid, rutin and quercetin from euphorbia hirta by successive extraction involves the use of solvents in an order of increasing polarity in soxhlet extractor at 30-45 °C using 800 ml solvents for 5 hours in increasing polarity to isolate the active constituents without other interferences. Hence we proposed to develop easy, rapid, accurate, precise and reliable analytical HPTLC method for the standardization of Euphorbia hirta(L) using gallic acid, rutin and quercetin as phytochemical markers from its methanolic extract and herbal capsule formulation. The separation was performed on TLC aluminum Plates precoated with silica gel 60F254, good separation was achieved in the mobile phase of butyl acetate: 1,4-dioxane (5:5% v/v) and densitometric determination of gallic acid, rutin and quercetin was carried out at 266nm.The linear regression data showed a good linearity in the concentration range of 136-748ng/spot of gallic acid, rutin and quercetin with a good correlation coefficient of 0.9989. Limit of detection was found to be 102 ng/spot of gallic acid,17ng/spot of rutin and 68ng/spot of quercetin. The limit of quantification for the estimation of gallic acid, rutin and quercetin was found to be 136ng/spot.

Accelerated stability studies of Emblica officinalis, Terminalia belerica and Terminalia chebula have been carried out as per ICH guidelines and its effect on total polyphenol content as determined by Folin-Ciocalteu method and Gallic acid content as determined by HPLC (High Performance Liquid Chromatography) was studied. The samples were kept in stability chamber at 40°C and 75% relative humidity for 3 months for accelerated stability studies. Samples were taken out at periodic intervals and extracted to determine total polyphenol content by spectrophotometric method and gallic acid content by HPLC. The HPLC method was also validated to demonstrate its selectivity, linearity, precision, and accuracy. The results indicate an increase in total polyphenolic content as well gallic acid content under accelerated stability conditions which is indicative of hydrolysis of gallotannic acids present in crude drugs to liberate free gallic acid, thereby increasing the total polyphenolic content.