VALIDATED STABILITY INDICATING HPTLC METHOD FOR PROTOCATECHUIC ACID

Protocatechuic acid (PCA) is a type of widely distributed naturally occurring phenolic acid, commonly found in bran, grain, brown rice, fruits such as plums, gooseberries, grapes and also in onion peels. A new, simple, precise, accurate and sensitive stability-indicating HPTLC method for Protocatechuic acid was successfully developed. This method is based on HPTLC separation followed by UV detection at 258 nm. The HPTLC method is used to determine the presence and quantify the protocatechuic acid in onion peel extract. The separation was carried out on Merck TLC aluminum sheets precoated with silica gel 60F254 using Toluene: Ethyl Acetate: Formic acid (6:6:1.2 v/v/v) as a mobile phase and scanning was done by using TLC Scanner III. Protocatechuic acid gave well defined and sharp peak at R-f 0.52 +/- 0.03 at 258 nm. The calibration curve was linear in range 100-500 ng/band. Protocatechuic acid was subjected to stress conditions like hydrolysis under acidic, basic and neutral conditions, oxidation, heat, and photolysis.