Application of a Validated Stability-Indicating HPTLC Method for Simultaneous Estimation of Paracetamol and Aceclofenac and their Impurities

Abstract

A sensitive, accurate, precise and stability indicating HPTLC method has been developed and validated for the simultaneous detn. of Paracetamol (PCT), Aceclofenac (ACF) and their impurities namely, 4-amino phenol (AP) and Diclofenac acid (DA), resp., which are the hydrolytic degrdn. products and related substances of the drugs. The chromatog. sepn. was achieved using optimized mobile phase, Et acetate: methanol: glacial acetic acid (8.5:1.5:0.25 V/V) on pre-activated silica gel 60 TLC plates with UV detection at 231 nm. Statistical anal. revealed linear relationships in the concn. ranges of 3900-9100, 1200-2800 for PCT, ACF resp. and 100-600 ng/band for AP and DA with correlation coeff. more than 0.99. The chromatog. conditions gave compact spots at Rf value (± SD) 0.60 (± 0.011), 0.21 (± 0.01), 0.83 (± 0.01) and 0.08 (± 0.015) for PCT, ACF, AP and DA resp. The method was validated as per ICH guidelines, demonstrating to be accurate and precise within the corresponding linearity range of analytes. Inherent stability of these drugs was studied by exposing drug substances to stress conditions as per ICH guidelines namely oxidative, thermal, photolysis and hydrolytic conditions under different pH. Relevant degrdn. was found to take place under these conditions. PCT and ACF were found to undergo extensive acidic and basic hydrolysis while ACF was also susceptible to neutral hydrolysis; producing stated impurities as their major degrdn. products. The developed method resolved the drugs from degrdn. products generated under stress conditions; with the peak purity values greater than 0.999. Thus, a new simple, accurate, precise, sensitive and economic stability-indicating High Performance Thin Layer Chromatog. (HPTLC)/densitometry method has been developed and validated for the simultaneous estn. of the titled analytes and their stated impurities in pharmaceutical dosage form. The high sensitivity and specificity make it valuable quant. method suitable to be employed in the routine estn. of impurities and in stability studies. [on SciFinder(R)]