Determination of Fluoxetine and Paroxetine in Pharmaceutical Formulations by Densitometric and Videodensitometric TLC

Two new, simple, rapid, and accurate thin-layer chromatographic methods have been developed for determination of fluoxetine in capsules and paroxetine in tablets. The drugs were chromatographed on silica gel 60 F254 plates in horizontal chambers with benzene-acetone-ethanol-25% aqueous ammonia, 9 + 7 + 2 +1 (v/v) as mobile phase. Densitometric detection was performed at λ = 218 nm and 293 nm for fluoxetine and paroxetine, respectively; videodensitometric detection was performed at λ = 254 nm for both drugs. The range of linearity was 2–10 μg per spot for fluoxetine and 0.5–8 μg per spot for paroxetine. The relative standard deviation for determination of these antidepressants in pharmaceuticals was less than 4.3% for densitometry and less than 4.9% for videodensitometry. Recovery of fluoxetine from capsules was 105.1% by use of densitometry and 104.3% by use of videodensitometry; recovery of paroxetine from tablets was 99.15% and 98.2%, respectively.