Development and Validation of Stability Indicating HPTLC Method for Simultaneous Estimation of Domperidone Maleate and Naproxen Sodium in Pharmaceutical Formulations

A high-performance thin-layer chromatographic method was developed and validated for simultaneous determination of Domperidone maleate (DOM) and Naproxen Sodium (NAP) in combined dosage formulation. The chromatography was performed on pre-coated silica gel 60 F 254 plates using Toluene: Dichloromethane: Ethyl acetate: GAA (5:3:2:0.1 v/v/v/v) as mobile phase. Densitometric evaluation of the chromatograph was performed at 272 nm. The two drugs were satisfactorily resolved with Rf values 0.12 ± 0.02 and 0.70 ± 0.03 for DOM and NAP, respectively. The accuracy and reliability of the method was assessed by studying linearity for DOM (10-60 ng/band) and for NAP (250-1500 ng/band), presicion and accuracy and specificity, in accordance with ICH guidelines. The method determined the two drugs simultaneously from dosage forms without any interference of the tablet excipients. DOM and NAP were also subjected to acid, base, oxidation, heat and photo-degradation studies. The degradation products obtained were well resolved from the pure drugs when subjected to acid and alkali degradation and oxidative stress. The developed method could effectively separate the drugs from its degradation products and hence can be used as a stability-indicating assay.