STABILITY –INDICATING DENSITOMETRIC METHOD FOR SIMULTANEOUS DETERMINATION OF DONEPEZIL HYDROCHLORIDE AND CURCUMIN IN INSITU NASAL GEL

A stability indicating high performance thin layer chromatography (HPTLC) method was developed and validated for determination of Donepezil hydrochloride and curcumin in in situ nasal gel. Study was performed on pre-coated silica gel HPTLC plates using toluene: methanol: glacial acetic acid (8: 2: 0.1 v/v/v) as the mobile phase. A TLC scanner set at 254 nm was used for direct evaluation of the chromatograms in the reflectance/absorbance mode. Method was validated according to ICH guidelines. The correlation coefficients of calibration curves were found to be 0.994 and 0.988 in the concentration range of 300–1800 and 120–720 ng band−1 for donepezil hydrochloride and curcumin, respectively. The method had an accuracy of 100.6 % for donepezil hydrochloride and 99.08% for curcumin. The method had the potential to determine these drugs simultaneously from dosage forms without any interference of the excipients. Donepezil hydrochloride and curcumin were also subjected to acid, base, oxidation, heat and photo-degradation studies. The degradation products obtained were well resolved from the pure drugs with significantly different Rf values. As the method could effectively separate the drugs from its degradation products, it can be used for stability-indicating analysis. Keywords: High-performance thin-layer chromatography, Donepezil hydrochloride and Curcumin, Stabilityindicating method